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Eimeria leukarti "coccidium"
Small Intestine. Europe and India. Uncommon in U.S.A. Large characteristic oocysts, dark brown in color. Enteritis has been reported.
Have been recovered from horses. its importance is not well defined, though association with diarrhea has often been reported. Trichomonas fecalis has been incriminated in one outbreak of acute diarrhea with 40% morality. Liquamycin recommended treatment.
Horse, South American, nonpathogenic
Common. 51 known species recovered from large intestine and cecum. Large number are associated with diarrhea (Equine Protozoal Diarrhea). The role of these protozoa is not clear -- they may cause the diarrhea, or be there as a result of the diarrhea. Levine’s book on Protozoa of Man and Domesticated Animals (Burgess) pictures several species.
Tincture of time and supportive therapy generally seems sufficient, unless dehydration and/or electrolyte occur.
The horse ascarid is very similar to A. lumbricoides, both in appearance and in its Life Cycle. Females about 15"; males about 11".
The adults live in the small intestine; pass eggs which contain a central mass which develops into an infective larva in about 2 weeks. Its migration through the body is the same as the pig ascarid. The prepatent period in the horse is 10-12 weeks.
Prevalence: Parascaris equorum has a cosmopolitan distribution. It is more severe in the south but it can survive rather severe winters and is not geographically limited in the U.S.
Ascarid infection is primarily a problem in young horses. Sucklings and weanlings are more susceptible than yearlings, while in mares this infection is uncommon and the infections are characteristically light. This decreased susceptibility as age increases is credited to an acquired immunity resulting from the earlier infections. Horses undoubtedly continue to pick up infective ascarid eggs in contaminated food and water throughout their lives, but the worms are generally unable to establish and maintain themselves in the older immune animals.
Ascarid eggs are very resistant to environmental conditions and may live for years in stalls, paddocks and pastures. Thus, the source of the infection for the young horses is the contaminated ground that was seeded down with ascarid eggs by proceeding crops of infected foals.
The injury produced by ascarids covers a wide range, from light infections producing moderate untoward effects to heavy infections which may be the essential cause of death. Death from ascarid infection is usually due to a ruptured intestine. Serious lung damage caused by migrating ascared larvae may result in pneumonia. More common, and probably more important, is a retarded or impaired growth and development manifested by potbellies, rough hair coats and digestive disturbance in colts (2 to 5 months old often). A thousand or mor worms are associated with clinical signs of disease.
Antemortem diagnosis can be made by findings characteristic eggs in the feces (very similar to those of ascarid lumbricodes). The large nematodes are often seen in the feces, particularly afte anthelminitic treatment. Recovery of adults during a post mortem examination is common.
Good sanitation and management practices can play an important role in the prevention and control of this infection. Actually, sanitation in the control of ascarids, as with the strongyles, is essentially the proper disposal of manure. The same general procedures apply to both infections; however, in comparison, ascarids are more difficult to cope with because of the extreme resistance to environmental conditions exhibited by the ascarid larvae enclosed in their tough eggshell.
A regular treatment program results in the best control of ascarids. No known agent can be employed prophylactically against ascarids in the way small doses of phenothiazine are used agaisnt strongyles. For the present, then treatment is limited to the administration of therapeutic doses at intervals. Periodic removal of the worms by treatment interrupts the contamination of the environment with eggs for the dame or succeeding crops of foals.
15.7.1 Strongyloides westeri - Intestinal threadworm
General Appearance:
Very slender, 8 to 9 mm long. Only females are parasitic. Characteristic esophagus.
Prevalence - Horses, donkeys and zebras. More probable in warm moist climates and unsanitary stable conditions.
Life Cycle:
Homogonic and heterogenic life cycle patterns. filariform parasitic femals produce larvated eggs - 40 mm x 50 mm. Rhabdidiform L1 may develop through 2 molts into infective filariform L3 (homogonic cycle) or through 4 molts into free living males and females (heterogonic cycle). Infection occurs through penetration of skin, transmammary or by ingestion of filariform L3.
Disease:
Acute doarrhea in nursing foals may occur with heavy infections. Onset has been noted to coincide with "foal heat" diarrhea in some cases. S. westeri may cause many diarrhea problems in nursing foals. Animals over 4 to 6 months of age are rarely infected. Immunity seems to develop after exposure.
Epidemiology:
Heavy exposure is thought related to poor sanitation and large number of L3s resulting from free-living generation. Oral ingestion and percutaneous infection are the usuall routes of infection but nursing foals become infected primarily by transmammary infection. Sanitation is the key. The larvae are susceptible to natural adverse environmental factors.
Diagnosis:
Small larvated ova typical of genus in diarrheic feces of foals. Scrape mucosa and examine for nematodes with magnification at necropsy.
Treatment and Control:
Thiabenzole is probably the drug of choice. Cambendazole, Ivermectin, Sanitation is essential to prevent heavy exposures.
15.8.1 Anoplocephala perfoliata
Posterior S. I. Anterior cecum. Cosmopolitan distribution. More common. One Europen Suvey. 15%-20% occurrence. 2.5 - 5 cm. Segments wilder than long.
15.8.2 Anoploecephala magna
S.I. Jejunum. Rarely the stomach. Relatively rare. 1%-3% incidence. Relatively rare. 80 cm. x 2.5 cm. short, board segments. Wide distribution.
15.8.3 Paranoplocephala mamillana
S.I. Duedenum. Relatively rare. 1.0 -4.0 cm. x 4-6 mm. Uncommon. Less than 1% Monieza pallida
Rare. Less than 1% in the USA, South Africa, Angola. 4 meters long. Resembles the Bovine and Sheep Tapeworms.
Life Cycle:
All indirect. Oribatid mites are intermediate hosts. Prepatent period = 4 tp 6 weeks.
Diseases produced and Epidemiology: Light infections cause no disease. Heavy infections: A. perfoliate - May seclude ileo-cecel opening. May see ulceration there A, magna - May cause catarrhal or hemorrhagic enteritis -- Paranoplocephala-no disease.
Diagnosis:
- 1. Eggs in feces + clinical signs
- 2. Post mortem examination
- 3. Signs usually related to multiple problems, such as stongyles or teeth
Treatment and Control:
Drugs -- Bithinol 7 mg 1 kg. Diphenthane - 70. Control -- Crop Rotation and cultivation in mite nos.
There are 40 species of strongyles represneted in the horse. Most are relatively small -less than an inch in length. The smaller ones are commonly known as small strongyles or cyliocostomes. The species of the genus strongylus are referred to as large strongyles, sclerostomes, palisade worms, red worms and blood worms. Although some strongyles occur in every horse, these three species are the most important pathogens.
15.9.1. Strongylus vulgaris - "two tooth strongyle"
15.9.2 Strongylus edentatus - "Toothless stongyle"
15.9.3 Strongylus equinus - "Large strongyle" (has 3 teeth)
15.9.4 Tridontophorus serratus - "Large small strongyles"
15.9.5 Tridontophorus tenuicallis " " "
15.9.6 Small strongyles or "cyclisotomes"
Strongylus vulgaris is the most important of the three due to the larval migration. It is the smallest of the red worms, females measure 20-24 mm. (almost 1"). Strongylus edentatus females -- 33-44 mm., and Strongylus equinus females -- 38-47 mm. are about twice as long.
Tridontophorus measure 10-25 mm, and have 3 pair of teeth. This genus overlaps with S. vulgaris in size, but has life cycle typical of the small strongyles.
Life Cycel:
The life cycle is direct. Eggs passed in the feces are typical strongyle and develop on the ground before hatching. They may hatch in as little as to hours. Larvae develop to the infective stage within 5 to 6 days. The third stage larvae is very resistant and may live many years (at least 4) on the pastures in fecal masses. The horse becomes infected per os. The larvae go the large intestine and burrow into the wall (muscular coat) where they undergo as short period of growth and molting. The exact time that they remain in the muscular coat of the intestine is not known because nodules are formed by their presence. But it possible for the 4th stage larvae (11 days). Migrate thry peritoneal cavity to liver (6-7 weeks) and pancreas and back again to cecum. Require a 5 month prepatent period. Smith and Jones suggest a hepatic-pulmonary type of migration.
Strongylus edentatus may be similar to that of strongylus equinus or may reach liver by portal vessels or may stay in wall of intestine for 3 months and return to lumen without migration.
Strongylus vulgaris according to Drugs and others, migrates toward the heart within the media of the arteries.
Life Cycle and Pathogenesis of Strongylus vulgaris:
The arterial lesion caused by Strongylus vulgaris are though by Poynter to originate as small microscopic deposits on the endothelium. They consist of fibrin accumulations which occasionally contain entrapped RBC’s. It is thought that these lesion are a result of injury to the endothelium by the passage of Strongylus vulgaris larvae. The fibrin deposit is incorporated into the intima by the endothelium groing over it. Similarly a larvae can incorporated into the intima.
In the tunica media where a larvae is located, there will be an increase of leukocytes between the muscle fibers. Eosinophils are numerous in these areas. As these lesions become chronic, muscle cells degenerate and deposits of fibrous tissues occurs.
The adult large strongles are all heavy blood suckers and may cause bleeding ulcers.
The larvae penetrate the mucous membrane of the caecum and colon. Some arrive in colic lymph nodes, others penetrate into a part of the small arteries -- intima, media, adventitial layers, or even into the lumen. They migrate up these intestinal arteries which lead ultimately tot he cranial mesenteric artery and aorta. The majority probably do not get as far as the aorata, but many certainly do particularly in heavy infestations. Possibly it is disadvantageou to go so far. In very heavy infestations, larvae "spill out" somewhere into the aorta. It is only a very short distance to the origins of the renal arteries and some migrate along these. Others roam about in all directions, some as far forward as the origin of the coronary rteries. Some migration takes place within the media of the arteries, even those of the largest size. This layer of the aorta has often been found to be the site of extensive irregular inflammatory lesion just as would be expected to follow wandering nematode larvae. These inflammatory areas contain large numbers of eosinophils among various types of round cells and some unidentifiable cells showing marked karryorhexis. They were plentiful in our present case. Frequently, above them, there is pronounced endothelial proliferation, and within this a portion of a larva is often visible. We think that larvae migrating within the media may gradually come to the surface at random, penetrating the intima little by little. The endothelium proliferates very rapidly in an attempt to contain and cover the irritating parasite. The question of these being difficulty in envisaging the progression of larvae towards the heart against the acrtic flow does not really arise if the migration is either within the media or is sub-endothelial. In any case, it is easier to imagine this than that immature nematodes can deliberately select, from various possibilities, and appropriate vessel to enter.
The occurrence of well-developed larvae, or juvenile adult worms, in situations which seem to suggest that they could have arrived there obly passage through the heart and lungs might be explained by the possibility of the migration of a minority of the larvae through the ymph vascular system. As we have mentioned, we frequently find stongyle larvae in the colic lymph nodes, of which there are a great number. Their efferent vessels give a direct access into the thoracic duct and on into the right heart.
Effect of Strongylus vulgaris:
The larvae of Strongyle vulgaris are important because of their location in the artery-primarily the anterior mesenteric artery which supplies blood to the large intestine. Their attachment to the lining of the vessel causes:
- 1. roughened lining of vessel -- produces an ideal site for fibrin and leukocytes to be taken out of the blood stream thrombi. These tend to block the vessel.
- 2. Weakened arterial wall--In addition to sucking blood the worms may have a secretion which weakness the epithelium. The weakened wall of the vessel results in an aneurysm (verminous aneurysm) which is quite common and which may rupture. The auerysms tend to thrombose quickly and throw off emboli when the animal is overworked. These aneurysms interfere with the circulation of the blood. This produces a lack of blood supply to the intestine which becomes predisposed to colic, (severe abdominal pain). Death may occur in severe cases. If an embolus lodges in the vessels which supply the muscles of the hind legs, sudden lameness occurs. It goes away as the circulation gradually supplies the affected areas, but repeated lameness is common. As a result of the larvae and adults feeding on epithelium and blood, typical signs of parasitism occur. The condition is called strongyloidosis or strongylosis. Both large and small stongyles damage the lining of the intestinal wall at the point of attachment. As they wander from place to place, abandoned areas may ulcerate, hemorrhage or become infected by bacteria. Infections seem to be more severe in colts and young horses. Enough worms will produce anemia, edema, digestive disturbances and emacition.
Postmortem Findings:
- 1. + anemia, emaciation, edema and/or ascites.
- 2. Erratic Strongylus larvae may be found in man organs and tissue, i.e. spleen, kidney aortic valves, etc.
- 3. Normal locations: nodules in small intestine and large intestine, liver, beneath peritoneal surfaces of body wall, (especially in right flank area) in the crnial mesenteric artery, iliac arteries, abdominal aorta, also found in the thrombi and in intmal proliferations in vessels.
- 4. Aneurysms, Thrombus. Emboli. Infarcts. + gangrenous enteritis, + fibrotic arterial lesions (healed) in 50% of the horses. Hemorrhagic nodules on serosal surfaces.
- 5. + Ulcers in large intestine, colon and cecum.
- 6. Nematodes, usually red in color, ranging between 1-30 mm. These parasites are recoverable from feces (13-36 hours?) after anthelminitic treatment. Their presence is helpful to your clients’ understanding of
- (1) the nature of the problem and
- (2) you are indeed with it (the problem) effectively.
Treatment: Summarized elsewhere
Diagnosis:
Although about 40 species are inclued in the small strongyles group, these forms are generally regarded as being much less pathogenic than the large strongyles. This impression is gained front their usuall small blood sucking actively and the loose association of the adult worms with the large intestinal mucosa. In addition, the migrations of the larvae are limited for the most part to wall of the intestine. Nonetheless, the encystment of the larvae and associated tissue damage, including nodule formation, may be extensive in heavy infections and undoubtedly impairs digestion.
Ordinarily, the large and small strongyles are nor differentiated by fecal examinations for eggs. The presence ad relative number of strongyle eggs in the feces do not necessarily indicate the presence of or extent of an aneurysm in an animal. However, the number of stongyle eggs in the feces may be regarded as a general index of the animal’s exposure to Strongylus vulgaris, because it is known to occur widely along with the other strongyles. Fecal culture examinations can be used to diagnose the presence of adults of this species by its characteristic third (infective) larval stage.
Strongyle infection is ubiquitous. Although horses of all ages are infected, the younger animals are particularly liable to serious injury. The worms carried by the older animals were as the important source of the infection for the highly susceptive foals. Grass and other vegetation on paddocks serve as the chief means of the spread of the infection.
Control:
- A. Several saitary and management practice will add in the control of stongyles. These are
- (1) clean, dry stalls
- (2) protection of feed and water from contamination with feces,
- (3) frequent pick-up of manure from paddocks and pastures,
- (4) manure composting,
- (5) chain harrowing,
- (6) clipping of pastures and
- (7) rotation of animal species in pastures.
Unformatately, with the advant of more effective medicinal agents, there is a tendency of neglect the hygienic aspects. Medication should supplement rather than replace wholesome food and water and clean surroundings.
Prevention and Control:
- B. The low level phenothiazine system functions in a prophylacitic or preventive way by markedly reducing or preventing the contamination of pastures with infective larvae. Thus, the liability of exposure is lowered considerably. This net effect is brought about the rather peculiar fourfold action of small amounts of phenothiazine on the strongyles. It results in
- (1) practically a complete cessation of egg production by the adult female worms, and further,
- (2) inhibits the development of infective larvae in the feces from the eggs that are produced. in addition,
- (3) this system is though to bring about the slow removal of the adult worms from the digestive tract, and
- (4) hinder the development of infective larvae after tey have been taken into the body.
The low level system consists of the daily feeding in the grain ration of 2 gm. of phenothiazine for the first 21 days of each month, followed by a rest period for the remainder of the month during which no drug is feed. The intermittent periods of dosing are repeated, month after month, on a year round basis in herbs with permanent pastures, where reexposure is heavy.
The recommendations for the application of the low-level system have been detailed as follows:
In foaling mares, the schedule of treatment should be started when the mares are brought up in preparation for foaling and breeding and continued as long as the mare has a foal by her side. If, after weaning, the mares are fed individually, the treatment should be continued. Barren mares should be placed under treatment when they are prepared for breeding, and providing the barren mare are fed individually each day, it is advisable to have them on a low level treatment. Sucklings may, however, be treated by tying the mare and allowing the foal to fed first from the mare’s feed box containing the 2 gm dose of pehnothiazine or by providing the foal with a separate feed box and feeding 1 gm. of phenothiazine daily for the first 21 days of each month. Weanlings and yearling should be placed on the regular 2 gm dose schedule. This may be continued in yearlings taken up for breaking and light training, and in horses in light training. Horses in heavy training and racing should not receive the low level phenothiazine treatment. Stallions should be on low level phenothiazine throughout the year.
There is no direct evidence of any toxic manifestation from the low level system of treatment in the horse. Horses have been observed to tolerate low level phenothiazine administration for as long as four years, during which time the drug was fed daily, rather than for the regular 21 day per month schedule. Some of these animals received 4 gm. of phenothiazine daily for the first two years of this study. No untoward toxic effects were observed in any of the animals. The mares were successfully bred each year and foaled normally, and monthly blood examinations over the four-years period gave no evidence of developing anemia.
The continuous administration of phenothiazine as practiced under the low-level system raises the question of whether drug resistant strains of strongyles will result from the nearly continued contact with the small concentrations of the drug. Although such as a development must be regarded as a possibility, there is no evidence that it has occurred in this country. One farm in central Kentucky has successfully used the system for a period in excess of 12 years without experiencing a decline in effectiveness.
In contrast, therapeutic doses have been regarded as less prone to result in phenothiazine resistance. However, investigations in England indicated that the efficacy of therapeutic doses for the removal of large strongyles has decline form 80% in 1942 to 15% in 1957. Quite recently, evidence of phenothiazine resistance has been found two farms in the central Kentucky region. Both of these farms have employed periodic therapeutic doses for strongyle control and preliminary evidence shows that the worm populations consisting of both large and small strongles are completely refractory to full (25 gm.) doses of phenothiazine administrated by stomach tube. The advant of new, broad-spectrum wormers reduces the importance of this finding. Thiabendazole, trichlofofon and dichlorvos should be considered along with phenothiazine -- CS2-- piperazine complex, in a program where therapeutic wormers are alternated. Resistance can be minimized in this way.
G. Good nutrition and health management are essential to a successful preventive medicine program.
Life Cycle:
Direct. Females deposit eggs in the perianal region. Eggs embryonate in 3-5 days. infective eggs fall off or are rubbed off and get into the bedding, feed, or water. When embryonated eggs are ingested, they hatch in the small intestine where larvae move to crypts of the glands. Larvae enter the lumen, move to the large intestine and develop to adults. Adults in te lumen of the large intestine feed on ingesta. Autoinfection or retroinfection, which is common with other pinworm infections, does not occur with Oxyuris sp.
Prepatent Period: Five months.
Pathology and Pathogenesis:
Larvae in crypts of the small intestine may cause a localized inflammatory process with inflammatory cell infiltration and ulceration due to loss of epithelium. Adults in the large intestine are nonpathogenic. When females lay eggs, there is an intense anal pruritis. Rubbing may cause hair loss on the tail, hyperkeratosis, and secondary bacterial infections. When the skin becomes thickened and scaly, horses may appear "rat-tailed". Affected animals are restless, nervous and loe condition.
Diagnosis:
presence of eggs around the anus. Since eggs are laid outside the intestine, fecal examination is not a dependable diagnostic aid . A history of anal pruritis and the characteristic loss of hair at the tail head are suggestive of a pinworm infection.
Control:
Good sanitation. Prevent feces from reaching managers and throughs. Bedding should be removed often. Treatment with compound that are effective against "strongyles" are usually effective against pinworms.
Large intestine of horses.
World wide. The parasite is found throughout North America, but is rare. It is also present in Hawaii.
Males are 2 mm long; females are 3 mm. Adults have a clubshaped esophagus similar to that or that of Oxyuris.
The entire life cycle is completed within the host resulting in autoreinfection. Transmission from one animal to another probably takes place by the ingestion of larvae in food or water that has been contaminated with feces from an infected horse.
The parasite is nonpathogenic. Tremendous numbers of worms may be found in individual animals with no apparent detrimental effects.
Finding parasites in feces at necropsy.
15.11.1 INTESTINAL PARASITES (con't)
Protozoa (coccidia) (*) - Prepatent period
1. Eimeria zur nii (15-17)*
7. Eimeria auburnensis (18-20)
2. Eimeria bovis (15-20)*
8. Eimeria alabamensis (6-11)*
3. Eimeria canadensis (p)*
9. Eimeria subspherical (P)*
4. Eimeria ellipsoidalis(8-13)*
10. Eimeria brasiliensis (p)*
5. Eimeria bukidononesis (15-17)*
11. Eimeria wyomingensis (p)*
6. Eimeria cylindrica (11-12)*
12. Eimeria illinoisensis (p)*
Coccidia. Protozoa. in Ox, Zebu, water buffalo
Large and small intestine
E. Zurnii in elk, caribou. Occysts from 9 to 46 microns - check book Protozoan Parasites by Norman D. Levine For more detail on size of individual species and other morphology
Eimeria zurnii - is the most pathogenic species in catle, followed by E. bovis in its severity. The latter along with E. auburnensis are two of the commonest in prevalence. The other common species are E. alabamensis, E. canadensis, E. cylindrica, E. ellipsoidalis and E subspherica. E. braziliensis is uncommon and nothing is metioned abut the prevalence of the other species. In regards to pathogenicity most species (other than E zurni, E. bovis and E.alabamensis) are only mildly pathogenic, however, they may add to the overall effect when multiple infections exist.
A diagnosis - of coccidiosis is made on symptomatology and the existence of large numbers of oocysts in fecal sample along with history of overcrowding and/or fecal unsanitary environmental conditions. It is primarily a young animal or calf problem . Older animals are for the most part resistant carriers. Maintaining animals under intensive conditions of overcrowiding in barns or lots results in heavier fecal contamination with the build-up of sporulating oocysts. This leads to the ingestion of large numbers of infective oocysts and even some resistant animals my develop symptoms of disease.
Symptoms - associated with the two most pathogenic species includes a bloody diarrhea in calves. With E. zurnii the feces are streaked with blood during the initial sign of disease, and becomes more severe with blood fluid, clots of blood and liquid feces being passed. Straining and coughing causeS this mixture to spurt out as much as 6-8 feet. The hind quarters may look as if smeared with red paint. Anemia, emaciation and weakness accompany the dysentery along with secondary infection (as pneumonia).
Lesions of hemorrhagic enteritis are present in the small intestine and cecum. In E. bovis infections, the lesions are more in the cecum and colon. The symptoms of disease appear long before oocysts begin to passing feces. This sometimes makes it difficult to confirm a diagnosis. However, the scraping of the intestinal mucosa ( of lower bowel) on clinically examination should reveal developing schizonts. On necropsy examination the microscopic examination of lesions reveal the diagnostic or etiological agent.
Prevention - should be aimed at avoiding over crowding and unsanitary environmental condition. AMPROLIUM ( 5 mg/kg) daily for 21 days is recommended as an aid in the prevention of coccidiosis caused by E. zurnii and E. bovis during the period of exposure. This same drugs used as a drench (9.6%) or soluble powder, or 1.25 percent feed crumbles as a top feed dressing in ration at a dose of 10/kg for 5 days is recommended for treatment for the same 2 pathogenic species. Decoquinate is also recommended for preventative measures - see textbook
13. Entamoeba bovis - amoeba - 20 microns - Protozoa
In rumen - feces - cysts 15 microns - nonpathogenic
14. Flagellates:
Several species have been recovered from the cecum colon, rumen and in the feces of ruminants, however, all are nonpathogenic species as Tritrichomonas enteris, Protrichona ruminantium and and genera: Monocercoma bodo, Spiromonas cercomonas and mono are recorded, however, must be taken into consideration when making a diagnosis of genital Trichomoniasis ( in cattle) caused by T. Foetus, a very common pathogenic species ( to be discussed under Genital System)
15. Giardia bovis - Giardiasis- flagelle - 19.6 microns - Protozoa in the duodenum and ileum.
The body is piriform to ellipsoidal and bilaterally symmertical-anterior end broadly rounded and the posterior end is drawn out - A large sucking disc is present on ventral side - The dorsa/side is convex - There are 2 anterior nuclei, 2 slender median rids - (axostyles), 8 flagella in 4 paris and a pair of darkly staining median bodies which are curved bars.
Pathogenesis
Not entirely known, however, large numbers of the trophozoites have been seen in cases of severe eneritis associated with severe diarrhea. They are very actively motile when observed on fecal flotation when using a normal saline mount or sugar flotation solution.
15.11.2 Flukes
- 1. Paramphistomum microbothroides - "common "rumen fluke" - Trematode
- 2. Paramphistomum cervi - 11 mmu " common remen fluke"- Trematode
- 3. Paramphistomum liorchis - 11 mm. "common rumen fluke" - Trematode (see rumen) young flukes produce eneritis in duodenum.
15.11.3 Tapeworms
1. Moniezia expansa- Large tapeworm - 4-5 meters -cestode
These cestodes inhabit the small intestines of sheep, goats, cattle, deer and other wild ruminants. M.expansa is generally distributed throughout the United States.
Life Cycle:
The eggs may be liberated from the segments in the intestinal tract of the host, or they may be passed out of the animal's body in sheared segments where as they are extruded from the proglottids.
Oncosheres are contained within a membrane known as a pyriform apparatus and after being expelled in the feces, eggs apparently cannot be ingested by mites unless they are anchored and fairly dry. A number of species of free-living oribatid mites serve as capable intermediate hosts, and these arthropods literally pierce a hole in M. expansa eggshells and ingest the contents which include oncospheres. The embryos subsequently are liberated in the digestive tract of the mites, and by means of their hooklets and penetration glands they pass through the gut wall to the bobdy cavity. During the summer months cysticercoids may develop in 6 to 8 weeks. Infection of ruminants results from the ingestion of infected mites which a free on the vegetation.
The cysticercoids are libaerated in the alimentary tract and mature tapeworms are found in the small intestines 35 to 38 days after infection.
Pathogenesis
These cestodes apparently cause very little trouble unless present in extremely large numbers. Pure infection in sheep have not resulted in any noticeable clinical signs nor in failure to gain weight. It should be emphasized that mature M. expansa are easily detected, whereas thousands of smaller nematodes may escape notice. There are some indication that heavy infections with trichostronglyles may influence the pathogenic potentials of M. expansa. It probably is for this reason that M. expansa has been associated with scouring in range lands.
Diagnosis:
These tapeworms can be diagnosed by finding characteristic eggs in the feces. The ova of M. expansa are triangular in shape.
Treatment and Control:
Although it is generally agreed that these tapeworm are not worthy of therapy, farmers frequently will demand it. Copper sulfate and nicotine sulfate soulutions are supposedly effective in removing these cestodes. This consists of 1% copper sulfate by weight and 1% nicotine sulphate by volume in water. The mixture is administered at the rate of 60 ml. for adult sheep, 30 ml. for lambs 6 months or older, amd 15 ml. for lambs under 6 months. Newer drugs includes the albendazoles. Kamala in 4 gram dosages has been widely used for treatment in lambs.
Arsenious trisulfide in a copper sulfate solution also has been reported effective for expelin M. expansa from sheep. Critical work has not been done on the treatment of cattle for these parasites. Where control is concerned, there is no practical method for eradicating the intermediate host of M. expansa.
2. Moniezia benedeni - "Large Tapeworm" - 6 meters X 26 mm - Cestode
These cestodes are found in the same host as M. expansa, and combined infections frequently occur. M. benefeni is very similar to M. expansa, and this parasite also is generally distributed throughout the United States. In contrast to the triangular shaped eggs of M. expansa, the eggs of this species usually are cuboidal.
3. Thysanosoma actinoides - "fringe tapeworm" - 150-300 mm -Cestode
This species is found in the small intestines and bile ducts of sheep, cattle and a number of other ruminants in the western United States In so far as is known these parasite have not been found east of the Mississippi River. Adult forms of T. actinoides usually are from 150 to 300 mm. The segments are short and conspicuously fringed posteriorily.
Life Cycle:
The life history of this species is not know, but probably it involves some arthropod intermediate host.
Pathogenesis:
These cestodes at one time were throught to be responsible for constant losses in sheep, and it was assumed that their pathogencity was associated with clogging of bile passages. Little emphasis now is being place on the pathogenesis of these helminths, however this type infection is of decided economic importance due to liver condemnations of infected animals. In endemic areas this might constitute 30 to 60 percent of all lambs slaughtered.
Diagnosis:
The eggs of T. actinoides can be demonstrated by fecal floation procedures. Some investigators described the oncospheres of these parasites as being contained in a pyriform apparatus, however, thorns are not present as in M. expansa. Eggs are described in capsules.
Treatment and Control:
There is no know therapy for the forms occuring in the liver while those in the small intestines may be removed by the same drugs employed for expelling M. expanasa. Because of lack of knowledge concerning the life history of these cestodes control measures cannot be recommended. Lead arsenate, niclosamide, cambendazole and albendazole are effective against tapeworms in cattle and sheep-only niclosamide (250 mg/kg) has been reported to be effective against T. actinoides.
15.11.4 NEMATOES
1. Toxocara vitulorum - "Ascarid" - 20-30 cm - Nematode
Host: cattle, zebu, Indian buffalo. Location, small intestineIt is a stout whitish worm.
Life Cycle:
Similar to T. canis - somatic migration leads to prenatal infection. Intestinal parasitic infection appears to be confinded to the first few months of calfhood. Apparently not a common parasite in U. S., however, is a serious pathogen of calves of Africa, Phillipines, Ceylon and India. (See T. canis.)
Diagnosis:
Is made on finding characteristic thick shelled unicellular egg in feces of calves from 3 weeks of age.
2. Oesophagostomum radiatum: Nodule worm - 22 mm - Nematode
In intestine cecum and colon of cattle and bison.
3. Oesophagostomum venulosum- Nodule worm 22 mm - Nematode
In cecum and colon of cattle rarely sheep goat, deer, elk.
The larvae of both nodule worms are found in the intestinal walls well as in other visceral organs as the omentum, liver, spleen and the regional lymph nodes where the former produce nodules. O. venulosum is not considered too pathogenic and rarely produce nodules. The adults are found only in the large intestine (lumen) and characterized by a rounded mouth collar, a large cephalic vesicle which is constricted behind its middle and the absence of an external leaf crown - Internal leaf crown has 38-40 minute elements (O. radiatum).
O.venulosum has no cervical alae but has both an eternal leaf crown with 18 elements and an internal leaf crown with 36 elements. The cervical papillae is located at the base of the esophagus in O. venulosum and just below the transverse groove in O. radiatum.
Life Cycle
Direct-Larvae penetrate intestinal wall where they remain 5 or 10 days/return to the lumen as 4th stage larvae. The prepatent period is around 6 weeks but subsequent infective larvae become arrested for some time and many may never return to the lumen.
Clinical findings included anorexia, severe and constant diarrhea which is dark and fetid, weight loss and death with some heavy infections in the young animal. In the older resistant host the nodules become caseated and calcify, thus decreasing the intestinal motility causing the possibility of stenosis and or intussusception.
Diagnosis:
Is difficult clinically because the strongyle type eggs are similar to the many other found in ruminants - palpation of nodules per-rectum is possible. Fecal culture technique may be used - Tratment similar to other gastro-intestinal trichostrongyles.
4. Bunostomum phlebotomum-hookworm -25 mm - Nematode Adults in small intestine.
Host:
cattle, zebra. Male 10-18 mm. Female, 24-28mm. Eggs, 10X40 microns and have blunt ends and blackly pigmented embroyonic cells, so they can be readily differentiated from other worms eggs in feces. In stable cattle an itching of the legs, probably caused by the entry of the larvae through the skin makes the animals stamp their feet and lick their legs. Hemorrhagic diarrhea, anemia and marked weakness especially in calves are the clinical signs- bottle-jaw also. This hookworm belongs to the subfamily Bunostominae which include nematodes whose buccal capsuls ventral margin bears instead of teeth, cutting plates but these are usually absent from Globocephalus-Includes
Genera: Necator, Bunosotmum, Gaigeria, Uncinaria.
Life Cycle ( see other hookworms) direct.
5. Cooperia bisonis Cooperid -9/5 mm - Nematode
6. Cooperia curticei - Coopered - 6.2 mm - Nematode Sheep-goat, cattle rarely.
7. Cooeria McMasteri 9mm - Namatode in cattle
8. Cooperia oncophore rarely 8 mm - Nematode in cattle and sheep
9. Cooperia pectinate- "Cooperid" - 9mm - Nematode
10. Cooperia punctate Coopered 7.5 - Namatode In cattle and sheep.
The above species are similar in size to other trichosrongyles of rumminants, in being very difficult to see groosly on necropsy examination although evidence of parasite lesions may be visible. As a means of distingishing these small trichostrongyles and others from gastro-intestinal tract debri or content, a strong iodine solution may be used to stain some on the mucosal scrapings etc., for 5 minutes. After the background ingesta and tissue are decolorized with a 5% sodium thiosulfate the nematodes are easily seen.
The cuticle of the anterior extremity of the worms frequently forms a cephalic inflation and the rest of the body cuticle bears 14-16 longitudinal ridges which are transeveresly striated. The spicules are stout, relatively short, pigmented brown and usually have a ridged wing-like expansion - vulva may be covered by a flap see Soulsby for more detail.
Life Cycle:
Similar to other trichostrongyles
11. Trichostrongylus spp. - small stomach worm - 5 mm - Nematode
( See stomach of cattle fro intestinal spp.)
12. Capillaria bovis - cappillarid - 25 mm - Nematode
13. Capillaria brevipes capillarid - 12 mm - Nematode
The above two species belongs to a group of nematodes which are closely related to Trichuris, however, they are small and slender and the posterior part of the body is not conspicuously thicker than the anterior part. The life cycle of species found in mammals is direct where as some of the life cycles of those found in fowl are indirect. Eggs are double plugged.
a. Capillaria bovis of the intestine of ruminants is fairly consmopolitan and the eggs measures 50X25 microns.
b. C. brevipes - is also listed in the intestine of sheep and cattle in U. S. and P. R.
14. Trichuris ovis "whipworms" - 70 mm - Nematodes
In cecum of cattle sheep and goats
15. Trichuris discolor - Whipworm - to 52 m - Nematode
in cecum of cattle sheep and goats.
The above whipworms belong to the family Trichuridae. Members of this genus are commonly call "Whipworms" since the anterior parts of the body is long and slender while the posterior part is thicker and much shorter. The hind end of male is curled and there is one spicule with a protrusible sheath which bears spines and a oblong swelling. Eggs are barrel shaped with double plugs. They measure 70 X 80 X 43 - microns and are unicellular when laid.
Life Cycle:
Direct- eggs hatch after being ingested by definitive host. The infective stage is reach in 3 week after pasing in feces, adults develop in cecum 3 months after infection. Heavy infections are not common but may occur in very young labs or in drought conditions where sheeps are red graduly ground. The eggs are very resistant. Congestion and edema of the cecal mucosa accompanied by diarrhea and unthriftiness are seen.
16. Nematodirus filicollis - "Thread neckedworm" - Nematode In cattle, sheep, goat and deer.
17. Nematoduirus helvetianus "Thread neckedworm" - 25 mm Nematode
18. Nematodirus spathiger Thread - necked "worm" 23 mm Nematode
The above species are often found entangled like thread. They are relative long with filiform anterior portion which is also inflated at anterior end. The tail end of the female is trucate with an appendage In the males the spicules are long and fused at the posteror end - The eggs are the largest of all nematode ova (to 260 microns) with 8 dark segments when freshly laid.
Life Cycle
Eggs hatch only after the 3rd stage (infective) larvae is reached. Further under natural conditions a period of esposure to low temperature followed by exposure to a high temperature is necessary for hatching Therefore the. infective larvae surrive cold winters to cause heavy infections in spring, while other trichostrogyles larvae are asually killed. These trichostrongyles are important in Great Britian, however, not necessariily so in USA. Severe dirrhea, may lead to dehydration and prostration. Such would be assoicated with heavy infections. The results of ingesting large numbers of freshly hatched larvae under spring raising conditions.
19. trongyloides papillosus- "Thread worm" 6mm - Nematode
In cattle, sheep, goat - similar to other species ( in equine and pigs)
Diagnosis:
larvated eggs in feces must be differientiated from ova of Dictyocaulus and Gongylonema
(See life cycle)
20. Chabertia ovina "Large mouthed bowl" worm - 20 mm
in cecum and colon of cattle, sheep, goat, and deer.
This species has a large cup-like buccal capsule which is surrounded by a double row of small cuticular elements leaf-crown) at its aperture. The eggs measure -105 x 50-55 microns.
Life Cycle:
Is direct and resembles that of Storngylus equinus.
Pathogenesis:
Worms are plug feeders and produce mucosal edema. In sheep more anemia is observed - blood sucking activity is incidental however, not as voracious as that of hookworms.
Diagnosis:
On fecal culture since strongyles type eggs resembles eggs of other nematodes etc. Infection in sheep causes unthriftiness. Feces are soft and contain much mucus, and may be streaked with blood. Strong immunity quickly develops and outbreaks are only seen under conditions of severe stress.
Eristalis tenax larvae - "Rat-tailed maggots, Dipterous insect - In feces and vagina (pseudoparasite). In cattle, man, (rarely) to 25 mm
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Found in Small and large intesines of sheep, domesticated and wild. Species in North American goats are not well know. Oocysts from 14 to 45u.
The disease state in sheep and goats is chiefly confined to young animals up to 4-6 months of age. Mixed infections are the rule and the species of clinical importamce are E. alongingi E. parva and E. nina - kohl-yakimovi.
In the U. S. it is a disease of feed lot lambs, with outbreaks of disease occurring when range reard lambs are move to intensive conditons of husbandry. Within 2-3 weeks of their arrival. Mortality may be as high as 10%.
Clinical signs- include brownish to yellowish greenish diarrhea which may be stroked with blood. Abdominal pain, some anemia, in appetence, weakness and loss of weight may occur. The pathological changes vary with the species involved. E. aloingi produce large gaint schizonts which cause enlargement of the villi. Pseudo-adenomatous lesions (papillomatous-like) observed from both the serosoal and mucosal surfaces of the intestine. The intestinal wall also may be edematous, thickened and hemorrhagic. These latter lesions in addition to being common with the other pathogenic species may also accompany those which characterizes E. aoingi infections. E. aloingi os probably the most common coccidium of sheep being found in 90% of sheep in a U.S. survey.
Is based on history, evidence of poor hygenic condition lesion on necropsy and presence of oocysts in feces.
Several sulfonamides are recommended as well as nitrofurazone.
15.12.1 FLUKES
1. Paramphistomum spp. see stomach "Rumen Flukes"
2. Cotylophoron spp. see stomach Rumen Flukes
15.12.2 TAPEWORMS
1. Moniezia expansa - Large tapeworm - 6 meters x 16 mm -cestodes
2. Moniezia benefini Large tapeworm - 6 meters x 26 mm -ces-tode
3. Thysanosoma actinioides-finge tapeworm - 30 cm-cestode (see cattle intestine)
15.12.3 NAMATODES
1. Ascaris suum swine ascarid -41 cm- Nematode
Insheep accidentally (see intestine: swine)
2. Oseophagostomum columbianum - Nodule worm
3. Oesophagostomum venulosum - Nodule worm
This genus is also sometimes referred to as "nodular worm" With O. columbianum the cuticle forms a mouth collar which is fairly high, shaped like a truncate cone and separted from the rest of the body by a constriction. The latter is followed by a cervical groove which extend around the ventral surface to the latera aspects of the body- A cervical alae extends from this point posteriorly on both sides/a cervical papillare is just below cervical groove.
The external leaf crown with 20-40 elements and the internal leaf crown has 2 elements to each of the external - with O. venutlosum, there is no cervical alae the cervical papillae is situated behind the level of the esophogus. External leaf crown with 18 and internal the leaf crown with 36 elements.
Life Cycle
Similar to Strongylus spp Infectivity is reached in 6-7 days and the larvae on being ingested may migrate into gut mucosa from pylorus to rectum and molt, growing to the length of l.5 - 2.3 mm and return to lumen of gut in 5-7 days and pass to colon to mature- with eggs being passed in 41 days.
Pathogenesis:
O. venulosum is relatively harmless and seldom produce nodules with heavy infections. O. columbianum is a serious pathogen of sheep, 200-300 worms constituting a severe infection in young sheep. Extensive nodular formation of both large, small intestine seriously interfers with absorption, bowel movement and digestion. Nodular formation is related to resistance or immunity, therefore in lambs and older sheep with no prior exposure no nodules are formed when the infective larvae enter the mucosa and return to gut lumen - In this case more adult worms are seen - cases where the resistance is high fewer larvae return to the lumen to mature but are walled off fibroblasts of the inflammatory reaction.
In regards to symptoms a marked and persistant diarrhea is observed in lambs. The feces may be dark green in color and contain much mucus and sometimes blood. In chronic cases constipation and diarrhea may alternate from time to time with conditon becoming progressivley worse leading to emaciation, cachexia and even death.
Diagnosis:
Feces may show 4th stage larvae in chornic cases with diarrhea or eggs - an identification of L3 in fecal culture is best since eggs- are not characterisitic. History and symptons also have to be taken into consideration.
4. Bunostomum tugonocephalum hookworm-26 mm - Nematode in small intestine of sheep - goat. larvae in stain.
Life cycle and Pathogenesis similar to other hookworms
5. Cooperia spp.
See Bovine intestine
6. Trichostrongylus spp See bovine stomach
7. Nematodirus abnormals- thread-necked worm-25 mm--Nematode
8. Nematodirus filicollis - Thread-necked worm- 20 mm-Nematode
9. Nematodirus rufacevastitatis Thread- necked worm - ?
10. Nematodirus spathiger - Thread-necked worm 23 mm - Nematode
See bovine intestine
11. Strongyloides papillosus Thread worm - 6 mm - Nematode
12. Capillaria bovis capillarid - 20 mm - Nematode
13. Capillaria brevipes - cappillarid - 12 mm - Nematode
See Bovine intestine
In regards to symptoms a marked and persistent diarrhea is observed in lambs. The feces may be dark green in color and contain much mucus and sometimes blood. In chronic cases Constipation and diarrhea may alternate from time to time with the condition becoming progressively worst leading to emaciation cachexia and even death.
Diaqnosis: feces may show 4th stage larvae in chronic cases with diarrhea or eggs - an identification of L3 in fecal culture is best since eggs - are not characteristic. History and symptoms also have to be taken into consideration.
Treatment:
Thiabendozole 50 mg/kg piperazine (4 gr per animal) 125 mg/kg.
4. Bunostomum tuqonocephalum - hookworm -26 mm -Nematode. In small intestine of sheep - goat. larvae in slain.
Life cycle and Pathogenesis similar to other hookworms
5. Cooperia sPP.
See Bovine intestine
6. Trichostrongylus spp.
See Bovine stomach
7. Nematodirus abnormals Thread-necked worm - 25 mm - Nematode
8. Nematodirus filicollis - Thread - necked worm - 20 mm
15.12.3 Nematode
9. Nematodirus rufaevastitatis Thread - necked worm - ?
10. Nematodirus spathiqer - Thread-necked worm 23 mm - Nematode
11. Strongyloides paoillsos - Thread worm - 6 mm - Nematode
12. Capillaria bovis - capillarid - 20 mm - Nematode
13. Capillaria brevipes - capillaried - 12 mm - Nematode
See Bovine intestine
14. Trichuris ovis - whipworm to 70 mm - Nematode
15. Trichuris discolor - whipworm - To 52 mm - Nematode
Both of the above whipworms are found in cecum of sheep cattle goat and bison - See Bovine - Nematode
16. Chabertia ovina - Larse - mouthed bowel worm - To 20 mm - Nematod
17. Skriabinema c)vis - Pinworm to 8 mm - Nematode
In cecum of sheep, goat - adult worms have 8 large complicated lips. The tail of the male is bluntly rounded and has a circular caudae expansion supported 2 pairs of processes. Tnere is a single in the male.
FLUKES
1. Paramphistomum spp. see stomach Rumen Flukes 20 CotYlophoron Spp see stomach Rumen Flukes
TAPEWORMS
1. Moniezia expansa - Large tapeworm - 6 meters x 16 mm - cestode
2 Monieza benedini - Large tapeworm - 6 meters x 26 mm- Cestode
3. Thysanosoma actinioides - fringe tapeworm - 30 cm - Cestode
NEMATODES
1. Ascaris suum - swine ascarid - 16 cm - Nematode
In sheep accidentally (see intestine: swine)
2 Oesophaqostomum columbianum - Nodule worm
3 Oesophaqostomum venulosum - Nodule worm -
This genus is also sometimes referred to as ''nodular worm". With 0. columbianum the cutical forms a mouth collar which is fairly high, shaped like a truncate cone and separated from the rest of the body by a constriction. The latter is followed by a cervical groove which extend around the ventral surface to the latera aspects of the body - A cervical alae extends from this point posteriorly on both sides/a cervical papillae is just below cervical groove.
External leaf crown with 20-24 elements and the internal leaf crown has 2 elements to each of the external - With O. venulosum, there is no cervical alae/the cervical papillae is situated behind the level leaf crown with 18 and the internal leaf crown with elements.
Life Cycle
Similar to strongylus spp. Infectivity is reached in 6-7 days and the larvae on being ingested may migrate into gut mucosa from pylorus to rectum and molt, growing to the length of 1.5 - 2.3 mm and return to lumen of gut in 5-7 days and pass to colon to mature - with eggs being passed in 41 days.
Pathogenesis:
0. venulosum is relatively harmless and seldom produce nodules even with heavy infections. O. columbianum is a serious pathogen of sheep, 200-300 worms constituting a severe infection seriously interfers with absorption, bowel movement and digestion. Nodular formation is related to resistance or immunity, therefore in lambs and older sheep with no prior exposure no nodules are formed when the infective larvae enter the mucosa and return to gut lumen - In this case more adult worms are seen - cases where the resistance is high fewer larvae return to the lumen to mature but are walled off fibroblasts of the inflammatory reduction.
Life Cycle:
is direct/eggs are fully embryonated when deposited by the female on the perianal skin - prepatent period in 25 days. S. alate is observed in the above hosts in South Africa. These worms are not too pathogenic, however, maybe confused with nematodes in the area. (OesoPhagostomum spp.) The eggs are asymmetrical, being slightly flattened on one side and measure 47-63* 27-36 microns.
18. Skraiabinema caprae - pinworm - 5-8 mm- Nematode
This species is reported in domestic goats and sheep in New Mexico and Peru. Similar to above species.
19. Sitarandi
Is found in the reindeer and caribou in Alaska.
The candian Northwest Territory and Siberia.
- *1. Eimeria debliecki - Coccidia 25 x 14 microns - Protozoa
- 2. Eimeria Perminuta - Coccidia 11 - 16 x 10 - 13 microns Protozoa
- 3. Eimeria cerdonis - Coccidia 29 x 21 microns Protozoa
- 4. Eimeria scabra - - Coccidia 16 - 23 x 10 - 17 microns Protozoa
- 5. Eimeria -- Coccidia 17 x.13 microns - Protozoa
Found in Large and small intestine
Coccidia are common in swine but little is known about the disease state or its importance. The disease state occur primarily in young pigs and the same conditions of environment as with other animals are the responsible factors. E. debliecki is the most prevalent species found in U.S.A.
Balantidium coli. Ciliate - Protozoon - Cecum and colon of Swine, man and several other hosts.
Primates, however. less prevalent in man and primates. The trophozoites are ovoid,m 30-150 by 25-120 microns. The micronucleus lies near the center of one side. Food vaculoes are also present containing blood cells, bacteria or other fragments. The surface is covered with oblique longitudinal rows of cilia. The cysts measures 40-60 microns.
Pathoqenesis:
usually a commensal in lumen of large intestine, however, may invade gut mucose when lesions produced by other pathogens exist. In man and primates it causes a dysentery and produce lesions similar to those of Enatomoeba histolytica.
7. Entamoeba coli. Amoeba, Protozoon In large intestine Swine, dog, man. to 30U
8. Entamoeba histolytica. Amoeba. Protozoon
In intestines of Swine, man. Trophozoites to 60u cysts to 20u
The above two species belong to family Endamoebidae which contain exclusively the parasitic amoeba which occur in the digestive tract of vertebrates and invertebrates. Multiplication is by binary fission and encystment is common. This family should be diggerientated from the family amoebidae which contain the free-living amoeba of water and soil. Member of the genus Entamoeba have a vesicular nucleus with a comparatively small endosome at or near center of nucleus, a varing number of chromatin granules occur in the periendosomal region and attach to nuclear membrane-cystscontaining one to 8 nuclei are produced.Levine recognises 4 major groups: 1. Histolytica group of which the cysts have 4 nuclei when mature and their chromatoid bodies are rods with rounded ends - In this group are E. histolytica, (in man and other primates, dog, cat rarely pig), E. Hartmanni (in some hosts), E. equi (in horse~, E. anatis (in duck), 2. Coli group of which the cyst contain 8 nuclei and their chromatin bodies are splinterlike. In this group are E. coli (which occur in the same hosts as E.(histolytica) E. wenyoni of goats, E. muris (in rodents), Eo caviae (in guinea pigs), E. cuniculi (in rabbit) E. Gallinarium in fowl.
(3) Bovis group contain l-nucleated cysts and their chromatoid bodies are either rods with rounded ends and less often splinterlike. In this group are E. ovis of sheep and goats E. bulbalis of the carabao, E. chattone of monkeys and endosome and a ring of small peripheral granules, but not cysts - members are found in the mouth. E. ginqivalis in man, other primates, the dog and cat E. equibuccalis found in the horse.
E. histolytica is the cause of amoebic dysintery in man, It is the only specles of importance. It is more prevalent in the tropics and subtrophic than in cooler climates. The trophozoite ranges in size from 10-60 microns. It has a finely granular endoplasm and the the ectoplasm in hyaline in appearance. Movement is by pseudopodia which are finger like. A single nucleus contains a centra endosome which is surrounded by a clear halo zone. The nuclear membrane is lined with fine chromatin granules giving the appearance that the nucleus is outlined by a ring of small beads. Active trophozoites contain food vaculoes with red blood cells
This feature differientiats this species from the non pathogenic members of the group.
Pathogenesis:
Penetration of host tissues believe to be related to lysis of epitheliu, by proteolytic enzymes. Bacteria (Aerobacter aerogenes, Escherichia coli) apperantly plays an important role in the invasion process. Lesions occur primarily in the cecum and ascending colon of man in which deep flask - shaped ulcers are observed when the protozoa invade deeper tissues. They may gain access to the lymphatics. This gaining entrance into the liver and more vital organs even the lungs in which absesses may develop. Although other hosts may become infected, the cat is especially susceptible. Monkeys infections may be of public health importance.
90 Giardia sp - Flagellate - 20 microns - Protozoa
100 Chilimastix mesnili - Flagellate - to 20 microns - Protozoa
110 Trichomonas sp - Flagellate - to 11 microns - Protozoa
The latter 3 protozoa are little importance in swine.
NEMATODES
1. Ascaris suum - ascarid - to 41 cm - Nematode
In small intestine - larvae in liver and lungs Reported from sheep. The adults sometimes migrate into the stomach bile duct etc. or lower bowel. It is cosmopolitan in distribution and is probably the economically important parasite of swine causing great annual losses in the meat industry .
Morpholoqy.
These are large stout bodies white round worms. The females measure up to 41 cm while males are from 15-25 cm long with a ventrally curved posterior end. The eyes are thick - rough shell and measure 50 -75 by 40-50 microns and unicellular when passed in feces.
Life Cycle.
The female produce large numbers of eggs (250.000 per day) that develop to the infective stage in 2-3 weeks. On being ingested they hatch in the intestine, penetrate intestinal wall and enter portal ciruclation to reach the liver within 24 hours after infection and by the 4th or 5th day molt here and in living to L3. The larvae are then carried to the lung (VIA the Hear) where they are arrested in the capillaries, later to break out and passed up the tracheal tree (hepato tracheal migration) to be swallowed to end up in the intestine 7-8 days after infection. The 4th molt occurs around the 1Oth day in the intestine. The 5th molt occurs in 21-29 days and the adults develop after 50-55 days with eggs appearing in feces 60-62 days (2-2 1/2 mos.).
Clinical Siqns
Depends upon the severity of infection with young pigs being primarily affected. During lung larval migration a cough ("thumps") is frequently observed indicating verminous pneumonia/stunted growth or unthriftness as evident by "pot belly" is also a common sign in moderate to heavy infetions. Postmortem lesions are those of focal hepatitis or cirrhosis (milk spots) along with pneumonia. Adult worms may oclude intestine and bile ducts causing other symptoms. Diagnosi is made by finding eggs in feces, sysmptoms and history (presumptive diagnosis).
Treatment:
Piperazine is probably the drug of choice. Dichlorvos, fenbendazole, and pyranted are also very effective with broad spectrum activity.
Prevention:
See Mclean Co. Swine sanitation program
20 Macracanthorhynchus hirudinaceus . "Thorny - headed worm" to 47 cm acanthocephalid - In small intestine. Seen in swine, cattle, fox and squirrel.
The adults have a transversely slightly pink colored cuticle. No alimentary canal exist. The proboscis has 6 rows of hooks. The body sometimes appear flat but in fixed preparation appear round. Adults are found attached. Egg measure 67-110x40-65 microns and have 4 shell which are dark amber.
Life Cycle:
lndirect - involving grubs or bettle.
Clinical Siqns: are not specific but on necropsy necrotic foci (surrounds the attached proboscis) can be seen thru the serosa
perofration leading to peritonitis and death sometimes is observed.
Diagnosis:
Difficult because egg do not usually float by the usual laboratory technics. Levamisole has been an effective therapeutical agent.
3. Ostophagostoum denattum - Nodule worm to 14 mm - Nematode
5 . O. lonqicadum - Nodule worm - 8 -14 mm - Nematode
6. O. brevicaudum Nodule worm - 8 14 mm - Nematode
7. O. qeorgianum - Nodule worm - 8 - 14 mm - Nematode
Adults in large intestine - larvae in mucosa. The most important species is O. dentatum. The cephalic vesicle is prominent but cevical alae are nearly absent. Cervical papillae are toward posterior end of esophagus. Nine elements are present in the extrenal leaf crown and 18 are in the internal crown.
Life Cycle:
Similar to other species in sheep.
Lesion:
similar to other species
Treatment:
Thiobendozole, levamisol piperazine dichlorvous and pyrantel are effective drugs.
Diagnosis:
Strongyle type eggs resembles those of Hyostronglus, m chostrongylus Globocephalus and necator. The use of fecal culture is required.
8. Trichinella spiralis - Trichina worm 3.6 mm - Nematode
Hosts
Occurs in small intestine of man pig, rat an many other meat eating mammals. Larval stage encyst in muscles of above host indefintely. Probably cosmopolitan in distribution. Male is 1O4 - 1.6 mm. long and female is 3-4 mm. The hind end of the male bears a pair of lateral flaps on each side of cloacal situated near middle of esophageal region.
Life Cycle:
is initiat2d with the intestion of infected meats with the liberation of encysted larvae within a few hours by the digestive process. Adults develop in 4 days with corpulation in 40 hours after infection - Male die shortly thereafter - Females penetrate gut mucosa and produce larvae which gain entrance into lymphatics and circulation to be carried all parts of body tobecorne eventually encysted in voluntary muscles especially very active muscles are those of diaphragm, tongue, larynx, eye, masticatory and intercostal Longivity of Encysted Larvae indefinite-reported cases for 11 and up to 24 years.
Prenatal Infection Rare - has been experimentally produced.
Pathogenesis:
Of public Health Importance - rarely diagnosed in swine and of no clinical importance in this host. Importance is in man in which the disease is acquired through the ingestion of infected meats from either wild or domestic animals, usually rare or insuffiiciently cooked pork or bear meat:
Symptoms in general may be similar to those of other conditions which include diarrhea fever, muscular pain and stiffnes, dyspnea, boarseness, sometime edema of face and deafness. Marked eosinophilia. Crisis in 4 days when larvae become encapsulated.
Diagnosis.
Symptoms, History, Larvae in feces? Biopsy section, Immunodiagnosis Tissue digestion using a 1% pepsin or Trypsin most reliable.
Animalo At meat insoection ??? Not practical
Treatment:- Thiabendazole
Control:
Human infection - controlled through cooking of park and other infected meats by exposing deepest portion to a temperature of 137F. Larvae also killed at - 35C for short period - C for 24 hours. U.S. Government regulation. Store mears not higher that 5F for 20 day or all parts should be heated to 137F.
9. Globocephalus urosuhulatus Hookworm - to 7.5 mm -Nematode
Adults in small intestine - larvae in skin.
Life Cycle and Pathogenesis:
similar to other species uncommon in USA
10. Stronqyloides ransomi - Threadworm - To 5mm - Nematode
Adults in small intestine larvae in skin a common cause of pig scours - since infective lare transmitted VIA milk of sow. It is primarily a problem in the very young.
Life Cycle
Similar to species of other hosts.
11. Trichuris suis - whipworm - to 50mm - Nematode
Adults in cecum and colon
This species closely resembles or identical to T. trichurua in man and other primates, yet not interchangeable. Male 30 50 mm long -female 35-50 mm, spricu spricule 2-3 m.m with blunt tip. Its sheath variable in the extent of its spinous armature?
Life Cycle
Eggs reach infective state in 3 weeks to several months depending on temperatures and environmental conditions. On being ingested, egg hatch, the larvae migrate to where adult states reached in 8 month, Anterior end or worm partially embedded.
Pathogenesis:
Quite severe in heavy infections in swine.
Annual loss in 1954 - $13,171,00 1965 - $34,000 in deaths and $683,000 in morbidity for a total of $717,000O
Clinical effects of large numbers of T. suis are anemia anorexia dysentery.
CANINE
Protozoa
- 1. Isospora canis - coccidium . 32-2x27-88 microns
- 2. I. ohioensis - coccidium - 1927 x 18-28 microns
- 3. I. burrouski coccidium 10-18 x 10 - 18
- 4. I bigemina coccidium 10 - 13 x 10 - 13
- 5. S. cruzi - most pathogenic cyst in cattle - coccidium
- 6. Sc miescheriana cysts in swine
- 7. S bestrami - S. ovicanis in sheep
- 8. S. betrami cysts in horse
- 9. 5. hemionilatrantis cysts in mule deer - coccidium
In regards to species of coccidia in dogs and cats there has been a tremendous amount of research and new discoveries in the past 10 years. The idea that these two host shared many of the same species has been disproven. Both genera IsosPora and Eimeria require one host in which they undergo schizogony and gametogony within the intestinal mucosal cells. Further development (sporulation) of oocyst passed in feces takes place in the external environment. Infection of definitive host occurs with the infective of sporulated infective oocysts etc. Sarcocystis require 2 host; the definitive predacious host in which gametogony and sporulation occurs in the intestinal mucosal cells and the intermediate host (herbivores) in which schizogonay occurs in the endothelial cells of the vascular system with cysts (Bradyzoites) development in skeletal muscle cells (fig. 9.8) Grossly these appear as yellowish or white spindle or cylindrical shaped structures lying in the muscle bundles, ranging in size from microscopic to several centermeters in length (latter in intermediate host only). Infection of definitive hosts occurs on ingesting bradyzoites in muscles etc. of intermediate hosts (livestock). Recently it has been shown that this genus may cause absorption and other clinical signs in cattle. Hammondi, a rare coccidium of cats resembles Isospora morphologically but are similar to sarcocystis in that it re~uires 2 hostsO The cat in which schizogony and gametogony occurs in the intestinal mucosal cells and the intestinal muscles after ingesting sporulated oocysted.
Pathogenesis
In dogs I. canis, although common is not that pathogenic. I. biqemina is the least common, but markedly pathogenic, puppies being seriously affected while adults are carries. The first signs usually appear around the 6th day infection. Catarrhal bloody diarrhea, rapid emaciation and anemia occur. Affected animals are weak, depressed and show loss of appetite There may be a rise in temperature or muscular tremor of hind legs. If animals survive the acute phase, the dysentery is replaced by a mucous stool for 3-4 days. Post mortem changes are those of a hemorrhagic enteritis. The other species of coccidia of dogs are only mildly pathogenic.
Sarcocystis spp are probably overlooked too frequently in stool sample and not that pathogenic in definitive host. Sporulated occysts passed in feces of host serve to identify this genus, usually only the sporocysts are observed. (micrometry is needed to differientiate the species of coccidia of the various host species). All other genera of coccidia sporulate several hours or days after passing in feces.
10. Balantidium coli - ciliate - 75 microns - Protozoa see Swine intestine
11. Entamoeba coli - amoeba - to 80 microns - Protozoa
12. Entamoeba histolytica - amoeba - to 60 microns - Protozoa
See swine intestine - primarily in man It produces a mild to severe hemorrhagic enteritis
13. Giardia canis - Flagellate - to 17 microns - Protozoa
Trematodes
1. Nanophyetus (Troglotrema) salmincola - "Salmon-poinoning fluke"
Host and Location: Small and large intestine of dog, fox bobcat, and coyote. Recorded from Oregon, Washington, and California. Case east of Mississippi would be "import" case.
Disease:
"Salmon poisoning" has been associated with this fluke; however, the etiological agent is Neorickettsia helmintheca. The flukes serve as transmission agents. Apparently disease is found only in dogs.
Life Cycle:
Three hosts are involved. aquatic snails (Goniobasis plicifera), fish (salmon and other members of Salmonidae) and carnivores. Eggs hatch is 3 months. The metacercariae are visible up to 3 1/4 months if kept just above freezing. Eggs passed 5-10 days after ingesting cyst.
Symptoms:
It appears that the rickettsia are so prevalent in flukes that anytime dog becomes infected with flukes "salmon poisoning" develops. The following are due to the rickettsia; onset is sudden; body temperature 103F to 107F, which continues for 1-2 days. By 3 to 6 days temperature returns to normal or subnormal Anorexia is an early sign which persists throughout the course of the disease. Depression, dehydration, and loss of weight can be noted. The dog exhibits extreme thirst and frequent emesis. Severe diarrhea usually commences at the time of temperature drop and the feces often contain great quantities of blood. A conjunctival exudate may also be presence at the medial canthus. Deaths usually occurs 10 to 15 days after ingestion of the fish. The somatic lymph nodes become moderately to greatly enlarged after fever.
Pathological Alterations:
Hemorrhagic enteritis usually extending from pylorus to ansus. Lymph nodes are hemorrhagic and edematous.
Diagnosis:
Symptoms and finding eggs in feces plus history of eating raw fish.
Treatment: Shaw and Howarth reported success with sulfonamides given when appeared in an artificial infection. Recovered animals immune. High levels individual doses of penicillin, chlortetracycline, oxytertracycline.
2. Alaria americana - Intestinal fluke - to 5 mm - Trematode
3. A canis Intestinal fluke - to 8.2 mm - Trematode
4. A. arisaemoides Intestinal fluke - to 10 mm- Trematode
5. A .michiganensis Intestinal fluke - To 109 mm - Trematode
The above species are characterized by a constriction which divides the body into an anterior expanded part. They are mostly in the lake regions of the country. Several species have been reported from the small intestine of carnivores (dog, cat, fox, mink) in the U.S. and in other countries. Heavy infections may cause a catarrhal duodenitis. The life cycle involve certain types of snails as the first intermediate hosts and frogs or rodents as the second intermediate host. Other flukes are as follows:
Family-Heterophyida:
Small trematode, usually not over 2 mm. long and wider posteriorly than anteriorly. Parasites in the intestines of mammals and birds where known, the life cycle includes two intermediate hosts--snails and fishes or frogs.
*Cryptococtyle linqua:
Occurs in intestines of carnivores (dog, cat, seal, silver fox, mink) and common in intestine of such aquatic birds as gulls and herons. Large numbers cause enteritis. Parasites are stunted in size in cats.
*Metagonimus yokogawai:
Occurs in the small intestine of the dog; cat pig, man and pelican in Eastern Asia and the Balkans.
Phagicola longa:
Has been reported from the small intestines of dogs, cats and foxes in North America and Israel.
TAPEWORMS
1. Dipylidium caninum- "Double-pored " or' cucumber seed tapeworm - to 70 cm.
Because of an unusual shape of segments, D. caninum often is referred to as the "cucumber worm". Thesë cestodes are found in the small intestines of dogs, cats, foxes wolves and related carnivores. Approximately 100 human cases are recorded, and nearly all of the these have been in children. The length of mature D. caninum specimens various from 5 to 70 cm, and the scolex is extremely small (250 of 500 microns in width). These tapeworms are cosmopolitan in distribution and the most common cestode parasite in dogs.
Life cycle:
The eggs are contained in "packages" within gravid proglottid and these are passed in the feces of dogs. Further development does not occur until the eggs are ingested by flea larva or biting lice. When this occurs, the tapeworm embryos hatch in the intestine an bore through into the body cavity of the arthropod intermediate host. D. caninum embryos then precede with their development into cysticercoids in about in about 30 days. D. caninum reaches maturity in a susceptible host within approximately three weeks following ingestion of cysticercoids.
Pathogenesis:
D. caninum infections in the dog usually are associated with no more than chronic enteritis, and often there is no change at all. In very heart infections, a severe hemorrhagic enteritis may occur, and in rare cases this species has been reported in the bile ducts.
D. caninum like many tapeworms does not produce arny marked clinical signs in the host unless present in large numbers. Diarrhea has been noted in dogs 48-72 hours after infection, but his subsides in a few days. The most frequently observed symptoms of this infection in dogs, although not cats, is the irritation produced by the passage of the gravid segment from the body. These, passing through the rectum or lodging in the anal frequently cause the animal to assume a sitting position and draw its anus over the ground. (bleb sliding) This is frequently observed by the owner, who often fail to notice the segments in the stool. Fresh or dried segment are often found in the perennial regions of infected dogs. Irritation of the abdomen is sometimes apparent in dogs, who will roll or drag over the ground or bite at the abdomen in an attempt to allay the itching.
Mild hyperesthesia with local muscle twitching, posterior incoordination and frequently recurring paroxysma of the characteristic "running fit" have been attributed to the presence of tapeworms. Convulsions and epileptiform fits occur, particularly in heavy infections in the cat.
Diaqnosis:
This infection may be diagnosed by finding the segments in the perianial region or occasionally the presence of the egg capsules in a fecal preparation. Dogs dragging their Anus over the ground shculd be suspected of diplidiasis or taeniasis.
Treatment and Control:
Di-Phenthane - 70 has been reported to be effective in the removal of cestodes from the dog. It is reported that his drug causes the disintegration of all the tapeworms in the small intestine. This drug will not remove all cestodes, but when used in combination with avesoline gives more satisfactory results. The toxic dose is approximately 10 times the therapeutic dose. The dosage suggested is 200 mg per kilogram (4 gr. per 3 pounds of body weight). Di-phenthane - 70 should not used in cats.
"Nemural: is also used in removing tapeworms from the small intestine of dogs, but its' use cats is inadvisable. It is given at the rate of 18 mg (1 table) for each 8 pounds of weight. Dogs should be accurately weighed and this drug does not act in 25 to 40 minutes it should be followed by a saline purge Aercoline hYdrobromide may be used for the removal of tapeworms, either alone or in combination with diphenthane-70. It is used at the rate of 0.0005 to 0.065 mg depending on the size of the dog. It should not be used in cats or very young dogs.
Kamala is useful in the removal of cestodes from cats. It is given at the rate of 0.6 to 1.0 grams depending on the size of the animal. It is frequently dispensed in combination with santonin and calome.
Gastro-intestinal lavage with 2 percent hydrogen peroxide has been used for the removal of tapeworms from the dog, but its use should be attended with care to avoid damage in the intestinal tract. It is advisable to fast over-night all animals that are to be treated.
The control of Dipylidium caninum depends on the control of the intermedia host, the flea and louse. Since these ectoparasites are almost universal present, constant attention must be paid to the treatment of infested animals. In the case of fleas, careful attention must be paid to the bedding of animals. Bedding should be cleaned at regular intervals with hot water or dry heat in order to kill the eggs and larval fleas. In homes of pet owners, the eradication of fleas is difficult due to the development of the larval stages in the furniture and rugs.
2. Taenia pisiformis - Rabbit cyst tapeworm - To 200 cm
Cestode
This cestode is found in the small intestines of dogs, cats, foxes wolves and related carnivores. T. pisiformis is very common parasite of dogs throughout the Southeast, and next toDipvlidium caninum it is the most common tapeworm of canines.
Life Cycle:
The eggs are passed out of the body in the gravid proglottids or rarely free in the feces. The eggs are ingested by the intermediate host, which may be a rabbit, squirrel, rat or a number of other rodents. The oncepshere is liberated in the stomach or small intestine of the intermediate host, and soon penetrates the mucosa, enters a blood vessel and is carried to the liver. The oncosphers migrate about in the liver parenchyma and after 22 days are usually to be found under the liver capsule where they have capsule and are found in the peritoneal cavity attached to the viscera. Numbers of large cysts, in old infections, are frequently found together filling the pelvic cavity. Infection of the host occurs by the ingestion of the cysticercus in the viscera. More common in rural dogs.
Pathogenesis:
Please refer to Taenia hydatigena of dogs. The pathologic manifestations of T. Pisiformis are very similar to those described for T. hydatiqena.
3. Hydatigera (Taenia) taeniaeformis - Cat tapeworm - to 60 cm
This cestode is found in the small intestines of cats, dogs, foxes, and related carnivores. It probably is the most common cestode of cats, and it is widely distributed throughout the United States.
Life Cycle:
The eggs of this species are ingested by various rodents, particularly rats and mice and also rabbits. The forms found in the livar differ markedly from those previously described (To pisiformis). The bladder is small and the scolex is not invaginated, but is attached to it by a long segmented neck. The larva is known as a strobilocerus (Cysticercus fasciolaris).
Pathogenesis:
Very little is known about the pathologic potentials of tapeworms in cats. It is probable that heavy infections will produce a syndrome similar to that described for T. hydatiqena in dogs.
Treatment and Control:
Kamale is considered the drug of choice for removing feline tapeworms. Di-phenthane - 70 also is commonly employed in feline medicine. The control of this species is virtually impossible, therefore frequent examinations and treatnent are necessary to prevent infection.
4. Taenia hydatigena - Sheep cyst tapeworm - to 5 meters
This cestode is commonly known as the "thin-necked bladderworm'', and it is found in the small intestine of dogs and closely related carnivores. Tn hydatiqena is the largest species of taenia occurring is dogs and it measures up to 5 meters in length. It is not a common parasite of dogs in the Southeast, however, "thin-necked bladderworms" have been found among white-tailed deer and sheep from Virginiar.
Life Cycle:
Dogs pass mature proglottids in the feces, whereas cattle, sheep, deer and swine ingest either the ripe proglottides or eggs. The oncosphere subsequently are released in the small intestine, bore through gut wall, and migrate to the body cavity. Cysticerci, technically known as Cysticercus hydatiqena, develop, attached to the liver capsule, mesesnery etcO Dogs acquire infection by ingestion of cysticerci.
Pathogenesis:
Light infections in the intermediate host do not produce clinical signs, but severe infections may cause the animal to be weak and unthrifty for several weeks and even death might result.
Infections with T. hydatiqena in dogs usually are not associated with more than a chronic enteritis, but severe enteric hemorrhage has been associate with heavy infections. Heavy infections also may affect the nutrition of the host by absorption food or interference with digestion.
Diagnosis:
This condition may be diagnosed in the dog by finding segments or ova in the feces. Necropsy is necessary for diagnosing cysticercosis in the intermediate host.
Treatment and Control:
For expelling T. hydatigena, either of the following drugs or combination therefox will suffice:
- a. Di-phenthane - 70
- b. Di-phenthane - 70 plus arecoline hydrobromide
- c. Nemural (Brand of Drocabil - Winthrop Laboratories).
Dogs should be kept from feeding on parasitized meat and viscera. Offal from farm animals and slaughter-house refuse should be carefully disposed or cooked if fed to dogs. Dogs owners should keep their dogs free of tapeworms through regular medicinal treatment. This will prevent contamination of pasture or hay.
5. Taenia oviso _ Sheep "measles" tapeworm - to 100 cm
This cestode is found in the small intestines of dogs and closely related carnivores. Mature specimens are about one meter in length. This species apparently is restricted to the western part of the United States.
Life Cycle:
Eggs are ingested by sheep and goats and the cysticerci develop in the musculature of these intermediate hosts. Infection of definitive hosts occurs by the ingestion of infected mutton of goat meat. Mature tapeworms are found in the dog about sever weeks after ingestion of viable cysticeric.
Pathogenesis:
"Sheep measles" has been applied to the condition where the cysterci infect sheep. Little is known concerning the reaction of sheep to this parasite, however, one worker produced death in expeximental subjects by feeding 10 gravid segments. Further loss can be expected from the condemnation of heavily infected carcasses by meat inspectors.
Diagnosis:
Fecal floation procedures will demonstrate T. ovis ova from dogs, and necropsy or slaughter will make possible the detection of cysticeric in muscle tissue.
Treatment and Control:
The standard drugs previously recommended for expelling T. hydatignea are effective against T. ovis. Since the farm dog is of greater importance in transmitting this infection it is essential that he be kept as free of tapeworms as possible. All carcasses of infected should be disposed of in such a manner that they are not accessible to dogs or related carnivores. As far as possible range animals which die should be disposed of so that they are incapable of infecting the definitive host.
6. Taenia crassiceps -to 170 mm - Cysts in subcutis and body cavity of rodents.
7. Taenia krabbei - to 20 cm. Cysts in moose, deer
8. Taenia Multiceps - Gid tapeworm - to 100 mm
This cestode is found in the small intestines of dogs, foxes, coyotes and related carnivores, but it is not a very common parasite in the Southeast. Multiceps is found primarily in the western United States.
Life Cycle:
The embryonated eggs pass in the feces of the infected dog or related carnivore, either free or contained within the gravid segments. These are ingested by sheep and the oncopshere is liberated in the small intestine. It penetrates the intestinal muscoa, and usually only those which reach the central nervous system continue their development. The cyst will wander around, on or in the brain or spinal cord and is fully formed in 7 to 8 months. The definitive host obtains the infection by eating the coenurs contained within the brain of spinal cord. About 3 to 4 weeks are required for the mature tapeworm to develop in the intestinal tract of the dog.
Pathogenesis:
The pathologic processes associated with M. multiceps in dogs are very similar to those described for T. hydatiqena. In sheep however here is a different story. The coenuri frequently located within the central nervous system and produce a condition known as "grid" or "sturdy".
The degree of clinlcal manifestations will be determined by the location of coenuri (coenurus cerebralis) in the brain of spinal cord.
Clinical Signs:
During early infection in sheep there are no marked clinical signs except for slight fever and restlessness. However, if the animal has been subjected to a heavy infection death may result. If the animal does not die no further symptoms are noted for 6 to 7 months, at which time the parasite will produce pronounced symptoms in various parts of the body, depending on the location oflthe cyst in the brain.
The worm also occurs in Ireland, Siberia, (Palestine), Japan, Central Africa, Chile, and in Michigan, Minnesota, Wyoming, Maintoba, Alaska, and Florida in North American. It has been thought that the worm was introduced in North American by Scandinavian lumbermen, but it may also have entered by the Bering Straits, or there may have been a native species in our wild carnivores before European or Asian man or dogs arrived. Worm from Manitoba and from Xussia look different, but there is so much variation in different host, and in worms differently prepared, that no specifically differential characters have been found.
Do latum reaches maturity in many domestic and wild species of the dog and cat families, in bears, and possibly other fish-eating carnivores. In North American the brown bear may be the normal host; dogs may not be as important since many of the eggs passed by them are not vaible.
D. latum is a vertiable monster, reaching a length of 10 to more than 30 ft,with a width of 10 to 12 or even up to 20 mm., and with a total of 3000 to 4000 proglottids in large specimens. Tarassov tells of a Russian woman who harbored six worms, aggregating over 290 ft.,and of another who supported 143 worms. Fortunately in tapeworm infections the size of the worms usually is in inverse proportion to their number. The proglottids for the most part are much broader than long, although the terminal ones become approximately square.
Life cycle:
Ciliated coracidia are ingested by suitable crusacean hosts in which procercoids are formed. The second intermediate host can be one of many fish species. Infection of the definitive host occurs through ingestion of partially cooked flesh of infected fish.
Pathogenesis:
Tapeworm infection in man and dogs usually are associated with no more than a chronic enteritis, but in heavy infections this condition may become severe and hemorrhagic in nature. In heavy infection mechanical blockage also may occur with partial or total obstruction of the alimentary cana. Some damage may be inflicted upon the digestive and nervous systems. This is thought to be a result of toxic substances that are produced by these cestodes and subsequently absorbed by the host. Tapeworms are capable of absorbing enough nourishment to produce the proverbial "tapeworm appetite".
Dipyllobothrium latum is unique among tapeworms in that sometimes it may cause a very severe anemia of the pernicous type. It once was thought that the anemia was produced by a toxic effect, but Chandler once suggested the absorption of a vitamin-like substance by the worms as a possible explanation. It subsequently has been demonstrated that D. latus actively soaks up Vitamin B12, absorbing 10 to 50 times as much as other tapeworms. In fact, the administration of powdered D. latum, along with gastric juice, is as effective in curing pernicious anemia as the administration of vitamin B12. Fortunately, the severe anemia cause by D. latum infection is exception rather the rule.
Diagnosis:
Finding characteristic pseudophyllidian ova by fecal floation procedures and correlation of clinical signs should afford adequate justification for diagnosis.
Treatment and Control:
Di-phenthane - 70 or kamale probably constitute the drugs of choice for expelling D. latus infection must depend mainly on more careful cooking of fish. Housewives and cooks preparing gefilte fish" should refrain from tasting the raw fish to test their skill flavoring. Some reduction in the infection of fish could be obtained by education and regulation with respect to pollution of lakes, and the practice of feeding raw fish to dogs and cats should be discouraged.
13. Spirometra mansonoides - Broad Tapeworm
This species has been reported from the small intestine of dogs and cats in New York and Louisiana. It is though the bobcat is the natural host for S mansonoides. These tapeworms are relatively small in comparison to D. latum, and they seldom a meter in length.
Life Cycle:
The life cycle of S. mansonoides is very similar to that described for D. latum, with the second intermediate host being and only exception. In this respect, plerocercoids develop primarily in mice and snakes.
Pathogenesis:
The disease producing potentialities of S. mansonoides are essentially the same as those described for D latum. Anemia apparently occurs more commonly in this infection than with the other cestodes of dogs and cats.
Treatment and Control:
Probably Nemural (Brand of Drobacil Winthrop Laboratories) would be the drug of choice for expelling S. mansonoides from its host. Control of this species revolves about controlling infections in mice and snakes. Since the intermediate host themselves would be virtually impossible to control, the problem must be primarily attacked by keeping the definitive host free from infections. In the case of wild hosts this would not be possible.
14. Spirometra mansoni occur in dogs and cats of far East. Closely resembles.
Diphyllobothrium. However, the first intermediate are cyclopidae and the second are frogs, and snakes rather than fish in which a sporganum develops. Sorgani are ribbon-like wrinkled pleurocercoid - Humans become infected when ingesting the infective stages in intermediate host or using infected reptiles as a therapeutic measures for conjunctives (Far East areas) Sporagnosis.
15. Mesocestoides variabilis - Mesocestoides tapeworm 50 cm
The genus Mlesocestoides has peculiar characters which include a posterior parunterine organ or egg ball. The number of species has been much disputed since the worms show considerable variation and there are no good differelltial characters. M. variabilis has been reported from dogs, cats, raccoons skunks, an in one incidence a child from east Texas. These parasites are extremely rare in domestic animals, however, they seem to enjoy a very wide distribution. M
variabilis measures approximately 40 to 50 cm. in length and the entire life cycle is unknown. Larval forms of these cestodes have been found in the bodies of reptiles, birds and small mammals, but the exact stage has not been determined. The significance of M. variabilis for dogs and cats is extremely vague.
16. Mesocestoides lineatus
Mesocestoides tapeworm - to 250 cm. Intermediate host for above two species are oribatid mites in which a cysticercoid develops and birds, dog, cat, reptiles in which tetrathyridium is formed.
17. Mesocestiodes carty
See attached page
Tapeworms of Man only
Taenia saginata (Adults in man only) - cysts in beef "beef tapeworm"
This is the commonest large tapeworm of man and is cosmopolitan in distribution. In some localities, e.g., parts of Africa, Tibet, and Syria, where meat is broiled in large chunks over open fires, searing the surface hut making the cysticerci in the interior only comfortably warm, it infects 25 to 75 percent of the people old enough to eat meat. In Hindu section of India T saqinata is relifiously ostracized, since only the lowest outcast will eat the meat of the scared cow or even of water buffaloes.
The beef tapeworm ordinarily reaches a length of 15 to 20 feett but specimen up to 35 to 50 feet have been recorded; the proglottids of an average worm number 1,OOO or more. The scolex is slightly larger than T solium, and without hooks.
Life cycle:
The life cycle is similar to that of T. solum, except that usually the intermediate host are cattle or related animals. This species also differs from T. solium in that bladderworms are prone to develop in man.
Pathogenesis:
The pathologic potentialities of T. saqinata are nearly identical to those ascribed to T. solium. T. saqinata does not constitute nearly as serious condition in man, however, as is the case with T. solium. This is because bladderworms of this species do not develop in man, and only the adult forms occur.
Treatment and Control:
Refer to recommendations pertaining to T. solium
Taenia solium in (adults in man only) cyst primarily in pork. "pork worm"
This worm is common in parts of the world where pork is eaten without through cooking, especially in some localities in Europe, but it is rare in the United States. In Jewish and Moslem countries, where the eating of pork is a serious religious misdemeanori this parasites has little chance of survival and is scandalous evidence of moral turpitued when it does occur, just as is the beef tapeworm in Hindu. It is a remarkable fact that in parts of the word e.g., North American, India, and the Philippines, human infectious with adult worms are so rare that many laboratories are unable to obtain specimens; yet bladderworm of this species are commoner than infections with the adult. This is one of the unsolved mysteries of Parasitology.
The pork tapeworm usually attains a length of 6 to 10 feet, and there are form 800 to 900 proglottids. The scolex is smaller than the head of pan and has a rostellum armed with 22 to 32 hooks.
Life Cycle:
A man infected with a pork tapeworm expells white segrnents singly or in short chains, almost everyday. These gravid segments are loaded with thousands of eggs, however, free eggs cannot consistency be found in the feces. The eggs probably survive in moist conditions for a long time. The filthy way in which hogs usually are kept especially susceptible, but bladderworms also can develop in camels, dogs, monkeys, and man.
Upon ingestion by a suitable intermediate host, oncospheres are liberated within the intestinal tract. The oncospheres bore through the intestinal wall and make their way via blood or lymph channels to muscle tissues in almost any part of the body. Having arrived at their destination they grow into bladderworms or cysticerci, technically called Cysticercus cellulosae. The cysticerci are small, oval, whitish bodies with an opalescent transparency. Pork containing these larvae is called "measly" pork, and it is infective for humans.
Pathoqenesis:
The damage done by adult taenias to their host is often either under or overrated. There are some who believe that the presence of a tapweworm is more or less of a joke, and as such to be got out of the system but not be taken seriously, whereas others become unnecessarily disturbed over them. They may cause mechanical injury by obstructing the intestinal canal and by injuring the mucous membranes where they ad here and they may absorb enough nourishment to produce the provorbialy raven "tapeworm appetite", although much more frequently they causes loss of appetite.
This species, however, is particularly dangerous because the bladderworms as well as the adult can develop in man, causing cysticercosis. Self infection with the eggs can result either from contaminated hands or by hatching of eggs liberated in the intestine.
Treatment and Control:
Tapeworms are affected by a number of drugs of vegetable origin-filix mas, Cusso, Kamala, Pelletierine, arecoline hydrobromide which have not been found effective against other helminths. Ethereal extract of Aspidium (filix mas or male fern) was the standard drug for expelling tapeworms from man for many years, and arecoline hydrobromide is still most extensively used for dogs. Prevention of cysticercus infections in cattle or pigs depends on care to prevent contamination of animals water of food by human feces.
Species: (Genera as listed under subfamilies)
1. A. caninum:
Host, dog, fox cosmopolitan distribution, probably most common helminth of dogs. (90% infection) Male 10-12mm; female 14-16 mm long --- color, red, due to blood in alimentary canal, 3 pairs of teeth on ventral margin of mouth opening.
Life Cycle: Direct
Transmission:
Ingestion of infective Larvae from soil or transclostrial transmission (larvae in milk of bitch keing transmitted to pup during first week after birth per cutaneous transmission (Larval penetration into skin) Transuterine transmission to unborn pups Stone and others have shown that transclostrial (Transmmary passage) transmission is not a major route of infection, whereas, it uters transmission is not a maior route of infection. Larvae ingested in milk mature in the small intestine without hepatotracheal migration larvae entering host through skin do pass through lungs and on to intestine. Larvae which infect pups prenatally pass through liver and lungs, etc., eggs 56 -75 microns 34-46 microns.
2. A. braziliense:
Host, dog, cat, fox, found in most trophical and subtrophical countries. Males 6-7mm, females, 7-10 mm; 2 pairs or teeth on ventral margin of mouth opening (one small and one large (eggs, 75-79 microns by 41-45 microns. The larvae of this species is noted for producing "creeping eruptions" in man (cutaneous larval miyrans).
3. U Stenocephals:
Host:
Dog, fox, cat. Male 5-8 mm. female, 7-12mm it has a pair of chitinous plates instead of teeth at ventral border of mouth opening. Eggs 65-80 by 40-50 microns; more prevalent in the colder parts of U.S. and Canada where it is common in foxes.
Pathogenesis:
Various degrees of anemia. Severe anemia in heavy inflections, hemorrhagic enteritis. Each worm is capable of sucking .8ml of blood in 24 hours. igrating larvae produce only mild reactions in lungs. Death in three weeks after birth in prenatal and transmammary transmission dark tary stool frequently observed in heavy infections.
Diagnosis:
Symptoms and presence of eggs in feces.
4. Physaloptera rara
Physaloptera worm - to 44 mm - Nematode seen in Duogenum and stomach of dog, cat and fox.
(see stomach parasites)
5. Stronqyloides sterocoralis - Tread worm - 202 mm - Nematode
In dog, fox, cat and man - Many books list Strongyloides canis or both.
Life Cycle
Similar to other species of genus. Clinical signs in puppies usually begin with a lack of appetite, purulent conjuctivitis, soft cough which may develop into broncho pneumonia. The cough is seen 7-10 days before diarrhea begins which is frequently blood stained. This develops shortly after prepatent period has been completed - Dehydration, anemia coma and death may follow depending on the severity of the infection. Infection is by transmammary (oral) or percutaneous routs.
Diagnosis:
is made by finding larvae in feces. Only other larvae found in the feces of dogs are from the genus Filaroides which have a wavy tail. Care should be taken when handling such cases since the larvae gains entrance thru skin - treatment in man, dog and cat has always been a problem.
Treatment:
Dithiazanine is effective in man and dogs. Thiabendazole will prevent mature Strongyloides infections in dogs when fed continuously at levels between 0.01 and 0.05% in ration. Diethylcarbamazine has also been effectively employed.
8. Trichinella spiratis - Trichina worrm - To 3.6mm - Nematode
9. Oncicola canis - Thorny- headed worm - To 14 mm
Acanthocephalid (similar species in swine)
The above coccidia are similar in many respects to those of other host species except those requiring 2 hosts - (Sarcocystis Toxoplasma and Hammondia, a rare species in cat). SarcocYstis sporulate within the host and are passed as such in the feces (a diagnostic feature) or in the sporocyst (9-15x7-12 microns) containing 4 sporozoites. Since the oocyst wall often ruptures. It is impossible to differientiate between species of sarcocystis by micrometry. The latter genus has come economic importance since meat carcases containing cysts stages on postmortem inspection are condemned for food consumption. The findings of oocysts smaller than 14 microns in cat feces should be regarded as Toxoplasma which ls of public health importance. This parasite has been reported from just about all species of animals (both wild and domestic) as well as man. Although sarcocystis does not usually cause any harm to the definitive host, it is of great importance to the herbivores host in which it may produce a fatal disease (see textbook - page 137 - 149).
Above genus in intestine of canine and feline also mink
Include species of snails in which sporocysts produce cercaria with bificated tails-- The latter sometimes (some species) encyst in frogs, etc. rodents (Paratenic hosts). Adult flukes develop in 10 days after infection. Pathogenesis - duodenitis.
Diagnosis ? Eggs 98 -134 x 62 - 68 microns
40 Other Intestinal flukes include genera Apophallus venustus, phagicola lonqa and Mesostephanus spp. all of which are less than 2 mm long.
See Dog Intestine since all species in this host also are reported in cats.
In cat, bobcat, lynx - intestine, stomach (rarely) similar to T. canis, however, no prenatal infection reported?
Similar to species in the dog - A.tubaeforme is comparable to A. caninum in dogs - but only slightly different morphologically - cats are seldom infected with many hookworms .
See intestine of swine
Similar to species in the dog - A. tubaeforme is comparable to A. caninum in dogs - but only slightly different morphologically - cats are seldom infected with many hookworms.
Chicken (Coccidia) See attached chart with species characteristics from W. REid.
OOcysts 11-42 microns-Protozoon - In intestine. Listed in order of their pathogenicity.
Oocyst in intestine of turkeys (*bobwhite quail pheasant, grouse)
Oocysts on sporulation contain 8 naked sproozoites (no sporocyst) uncommon -highly pathogenic
Coccidiosis in domesticated poultry is of great importance especially in chickens in which E. tenella and E. necatrix are the two most important species and are known as the "Killer type". However, in recent years, the use of excellent cocciostats has greatly decreased their importance therefore the other species of lesser pathogenicity are becoming more prevlent. In 1965 the USDA estimate the annual losses due to ooccidiosis at $34,854,00 To this should he added the cost of medicated feed and other related costs.
Infections of ccccidia begin with tne ingestation of sporulated oocysts cantaining the infective sporozoites.
Each spororozoite can prduce 900 first generation merozoitesp 350 second generation merozoites or one oocyst can yield 2 million second generation merozoites.
Host lesions are clirectly related to the growth phase of the second generation Schizont; for they cause loss of intestinal lining, hemorrhage and Lpredispose the bird to secondary infections.
The different species affect dirferent parts of the intestinal tract and in different degrees.The symptoms for each are genrally the same and incude loose of bloody stool, droopiness, listlessness and paralysis. Oocyst may be passed in droppings of birds which survive.
E.tenella- most easily recognized., causing a cecal coccidiosis (slight thickening in young birds especially. It is a progressive disease with hemorrhagic dropings first seen 5 days after infection. Oocyst appear onday 7 in the feces. Birds looses appetite and energy and those that survive loose normal functions of the cecum.
Most common rsponsible for laying house coccidiosis and is most prevalent in broilers. Surviving birds are more susceptible to other infectious and a drop n egg production is a common seguella. The lesions are confined to the upper part of the small intestine, which can be seen as whitish streaks and petechial hemorrhage.
Effects weight gains and pigmentation which have an effect on market price of the birds. Lessons in the middle and lower portion of the small intestine are found in the form of dusters of red or blush-red spots. this species may coincide with E. acervulina infection. E. Brunetti, E. mitis, E. Pracecox and E. mivati attack the upper intestine mainly and are of little pathogenic importance in the bird although there may be some latent economic backlash.
Attacks the lower G.I.T. causing round pin point hemorrhagic spot which may eventually cause a sloughing of the intestinal lining. The species of Eimeria in turkeys attack mainly the cecum on rectum and small intestine causing the same types of symptoms.
In some test it has been shown that the gastrointestinal flora is necessary for the development of the typical focal cocidiosis in poultry. The specific role of the flora is not understood but a lack of it causes a delayed development and reduction in the number of coccidia.
Severe coccidial infection have been shown in test to cause significant increases in prothrombin time in broilers thereby decreasing blood coagulation and may involve only one clotting factor affecting the extrinsic cloting pathway and is undoubtably the cause of the hemorrhage.
Finding oocyst in feces; past flock history; symptom of bloody droppings differential diagnosis include
Because of the excessive production of oocyst, coccidiosis is difficult to control. Crowded ad unsanitary conditions help propagate the infectious.
In turkeys' E. adenoeides, E. meleagnmitis, are considered to be the most pathogenic species with E. dispersa being only slightly pathogenic. The other species are relatively non-pathogenic. However, none reach the severity as those in chickens.
The above species are given to impress upon your mind that there are others which could have been listed, many of which are non-pathogenic.
In ceca and liver - Turkey, chicken,duck, goose, guinea fowl, pigeon, grouse, partridge peafowl, pheasat, quail.
Morphology
Some what pleomorphic, depending on the organ location and stage of the disease. In cecum it has a amoeboid appearance and at times has 1 and 2 flagella which arise from a small belpharoplast. Flagella are absent when organisms are in tissues.
Reproduction by binary fission - Primary infection through ingestion of ova of Heterakis gallinae (cecal worm) or direct ingestion of freshly passed organisms from acutely infected bird.
Essentially a disease of young poults in which high mortality is observed. Chickens are more resistant- Earlier lesions bseen in ceca consist of small, raised pin-point ulcers which enlarge to involve entire Ceca/Mucosa become necrotic and contain an hard core of caseous material. Ceca may be enlarged and hemorrhagic. In the liver circumscribed depressed areas of caseous necrosis are prouced, these are yellowish green in color- Synergism is suggested as a factor responsible for death and lesions?
appear 8th day after infection (3) decline in feed intake, degression, drooping wings ruffeled feathers, sulfur-yellow colored droppings - cynosis of comb and wattles and skin (Blackhead) is not constant.
Postmortem lesions in liver - cecal lesions may be confused with cecal coccidiose -Demonstrate eitiological agent?
Enheptin in drinking H2O or food Nithiazide and 1% Furazolidone are also two other very effective drugs.
Avoid raising Turkeys and chickens together - utilize regular treatment schedule for controlling cecal worms (phenothiazine-raise bird on wire floors.
In cecum and liver- chicken, turkey guinea fowl, quail, pheasant, partridge.
The organism is pear shape with 4 anterior flagella and axostyle project beyond posterior end of body. Lesions similar to those of histomoniasis. However lesions are irregular and raised.
In intestine of turkeys, partridge, pheasant, quail
Bilaterally symetrical, pear-shape with 6 anterior and 2 posterior flagella-transimission through contaminated feed and water-Enteritis -upper digestive tract-distended bulbous areas with watery content-foamy diarrhea.
Hexamita columbae - to 9 microns
Trematodes Mostly in Waterfowl
In intestine of ducks and chicken - A Strigeidae in which worms are constricted to form anterior flat or cup hape portion posterior part cylindrical.
In chicken, wild waterfowl
In duck goose chicken turkey swan
In duck, goose
The above latter 3- (Nos 2, 3, 4) belong to family
Echinostromatidae which include worms which are more or less enlongate with oral and vevtral suckers not to far apart with latter displaying a stronghead collar - oral sucker with 1-2 rows of spines.
Similar to Fasciola however, cercaria may enter another snail, amphibian or fish in which it becomes incysted.
5. Other genera include Motocotyle, Paramonostomum, Riberoia, Strigea, Zygocotyle.
Some eighteen or more species have been reported - The following species are more common.
This is one of the most common tapeworms of turkeys and it inhabits the small intestines of these birds. These cestodes measure approximately. 20 mm in length. Although chickens have not been experimentallyinfected with M. lucida, it is reported that they occur in this host. From 2 to 6 weeks are requied for the cysticercoids to develop in grasshoppers.
Turkey become infected by ingestion of cysticercoid containing grasshoppers. Little is know concerning the pathogenicity, treatment or control of these parasites.
This cestode inhabits principally the jejunal region of the small intestine of chickens and turkeys and is widely distributed among these birds in the United States. These tapeworms measure approximately 20 mm. in length. From 3 to 4 weeks are required for the cysticercoids to develop in a variety of insect intermediate hosts, which include houseflies, grasshopper and several species of Beetles.
Chickens and turkeys become infected by ingestion of these cysticercoid containing insects. Little is known concerning the pathogenicity, treatment or control of these parasites.
This is the smallest adult tapeworm found in man, but it makes up for its diminutive size by the large numbers which often are present. The "dwarf tapeworm" has a worldwide distribution, and it has been estimated that in the southern United States from 1 to 2 percent of children are infected at one time in their lives. The adult worm ranges in size from 7 to 0ver 100 mm. in length.
Hymenolepis nana differs from almost all other tape worms in being able to complete its entire life cycle in a single host. In this it is radically progressive, having broken away from age-old tapeworm custom of utilizing intermediate hosts. It can, however, still revert to the habits of it's ancestors and develop in fleas or grain bettles. When the eggs are ingested by man, rats , or mice, the oncospheres begin to claw actively inside their shells, and escape in the lumen of the intestine. They burrow into the interior of the villi and there develop into tailless cysticercoids in about 4 days. On reaching maturity these escape into the lumen of the intestine, the scoleces attach themselves, and the worms grow to maturity in about 15 to 20 days. In grain beetles, however, development of the cysticercoids takes 12 to 14 days.
H. nana causes rather evere toxic symptoms, especially in children including abdominal pain, diarrphea, convulsions, epilespsy, insomia, and the like. Diagnosis is easily made by finding the eggs in the feces: like nematode eggs, they float in strong salt solutions.
This cestode had been reported from chickens and turkeys in the United States, and also from quail collected in Maryland. These tapeworms measure approximately 2 cm. in length. About 3 weeks are required for the cysticercoids to develop in dung beetles. Definite pathologic conditions have not been associated with this species.
This is one of the most common tapeworms of the duodenum of chickens and turkeys in the United States. It also has been reported from quial in Michigan and Mississippi. These cestodes measure from 3 to 8 cm. in length and are composed of many hundreds of segments.
7. Eimeria innocua equired for the Cysticercoids to develip in a variety of insect intermediate hosts, which include stable flies, flour beetles and dung beetles. Chickens and turjeys become infected by ingestion of the cyticercoid containing insects. These tapeworms sometimes occur in large numbers among chickens and turkeys, but little effects on the growth rate of these birds have been noted.
In the United States, this tapeworm is not as cosmopolitan in its distribution as some of the other cestodes of poultry. It is found chiefly in the more moist regions and reported from both the Eastern and Western coastal states. D. proglottina attains a length of approximately 4 mm., and the strobila consists of from 2 to 5 segments, rarely as many as 9. Cyticercoids of this tapeworm develop in approximately 3 weeks in snails and slus Birds become infected by ingestion of cysticercoid containing snail and slugs. D. proglottina is considered to be one of the obviously dangerous tapeworms of poultry.
It has been observed that infected birds become emaciated and dull, with a dry and ruffled plumage. At necropsy, and may contain large quantities of fetid material. These worms have been reported as being capable of killing poultry.
This fowl cestode probably is one of the most common species occuring in poultry. It is rather large and inhabits the duodenal and jurjunal regions. Mature worms may attain a length of 12 cm. Cysticercoids develop in various types of beetles, and from 3 to 4 weeks are required for the infective stage to be realized. Chickens and turkeys become infected by ingestion containing beetles.
This worm has been reported to cause degeneration and inflammation of the point of attachment by the rostellum. Heavy infections in young birds may cause emaciation and retarded growth rates.
This fowl cestode apparently is widely distributed among poulry. Mature specimens measure up to 25 cm. long and they inhabit the small intestines of chickens and turkeys. Cysticercoids develop in tow species of ants and probably 3 to 4 weeks are required for the infective stage to be realize. Chickens and turkeys become infected by ingestion of cysticerocercoid containing ants.
According to the literature, this worm causes the formation of tubercules within the intestinal wall of infected birds, and the condition resembles tuberculosis. Loses attributed to R. echinobothrida have been reported in the vicinity of 50% of affected flocks in Maryland. Death occurs suddenly, and frequently is accompanied by convulsions.
This worm is morphologically similar to Echinobothrida, and measures approximately 25 cm. long. Although R. Tetragona frequently occurs in domestic poultry, it is of major significance for quail. In heavily infected birds, the intestinal lining frequently sloughs. But this parasite rarely has been associated with distinct tuberculosis-like lesions. The life cycle of R. tetragona is very similar to that of R. echinobothrida, and ants serve as intgermediate hosts.
Heterakidae-males have preanal suckers parasites
Medium to large worms.
Male, 50-76 mm, Female 72-116 mm. - Eggs are oval with smooth shell and are unsegmented when laid, they measure 73-92-x 45-57 microns.
Eggs pass in feces - become infective in 10 days on being ingested intestine, remaining in the lumen for 8 days - Then migrate into intestinal wall for 8-17 days. The larvae return to the lumen to mature in 6-8 weeks.
Finding egg in feces and worms on necropsy
Piperazine compounds, Hygromycin B. 8g/ton of feed for 8 weeks for control.
Life Cycle - direct - eggs have thick smooth shell and unsegmented when laid-measures 65-80 x 35-46 microns - become infective in 14 days or longer - Hatch on ingestion in intestion within 1-2 hours. L2 in mucosa for 2-5 days- L3 reached in 6 days - L4 reached in 10 days - L5 reached in 15 days - Eggs passed in 24-30 days. Earthworms serve as mechanical carrier.
Of minor importance. Its major importance is in its role in transmitting. Histomonas meleagridis.
The above two species produce a severe hemorrhagic enteritis with sloughing of mucosal surface.
Life Cycle- indirect? Earthworm appear to be required for the hatching of the double plug eggs which measure 60-65 x 23 microns.
In small intestine of pigeon and dove. Worms measure 24 mm. and are hair like and red in color. Life Cycle - short - 9 days. Symtoms and death may occur before eggs are passes infeces. Birds may vomit bile like material not too important presently. However, at one time when pigeons were used in signal corp it was of great importance. Eggs not characteristic - Strongyle type. Trichostrongyles - to 11 mm - In ceca and small intestine of fowl, chicken, turkey, goose, guinea fowl, pheasant quail.
Stongyloides avium - Thread worm - to 2.2 mm - In cecum small intestine - chicken, coot, junco, eggs larvated and measure 52-56 x 36-40 microns.
