Chapter 1

Colitis X (Peracute Toxemic Colitis)





A peracute toxemic colitis which is a highly fatal inflammatory condition of the cecum and large colon, characterized by sudden onset of profuse water/diarrhea, altered cardiovascular function. This condition, previously called exhaustion, shock ,and colitis X Colitis X has been used to describe cases of colitis in which a specific etiologic agent was not identified.

Peracute toxemic colitis is sporadic and has been associated with stress, antibiotic administration and experimental anaphylaxis. This condition also occurs in horses which do not fit the above criteria, and have been perfectly healthy.

The condition cannot be differential from salmonellosis and some cases of Peracute Toxemic Colitis are probably salmonella.

The condition also resembles some case of Potomac Fever (Equine monocytic Erlichiosis) 

1.1 Etiology

Because of the association with stress (such as strenuous exercise), transportation, deworming and antibiotic. TX, suggest that the condition may be brought on by changes in the microflora of the cecum and colon decrease in a number of VFA producing bacteria (Anaerobes), increase numbers of gram-negative enteric bacteria (including Salmonella) and decrease anaerobic fermentation of soluble carbohydrates into VFAS --> increase fermentation of carbohydrates into lactic acid-->decrease in cecal and colonic PH.

Resulting in damage to the cecal and colonic mucosa and allowing increase uptake of absorption of endotoxins from the lumen of the gut. 


1.2 Clinical Signs

1.3 Hemogram changes include:

Increase PCV, increase total protein - dehydration.

The PCV may be as high as 70-80%, TP - 8 - 12g/dl. The total protein will fall as the condition progresses due to protein loss through the cecum and colon. This drop in protein can occur within 48-72 hours. Plasma fibrinogen may increase to 600-800 mg per dl, due to the degree of inflammation.

Leukopenia is characteristic and can be attributed to PMN migration to the cecum and colon. As the condition progresses the PMN count decreases to zero in some cases, and the Band PMN count increases, many of the juvenile PMNS have toxic changes.

Increase BUN and Creatinine, due to dehydration or some direct effect on kidney.

Increase blood glucose, due to increase in catecholamines SGOT increases due to Endotoxin effect on hepatocytes. Hyponatremia, hypochloremia, hypokalemia due to decreased colonic absorption. 

1.4 Pathologic Findings

Confined to cecum and large colon, which appear reddish blue on the serosal surface. The mucosa is hyperemia and edematous and may be sloughed over large areas. The cecocolic and mesenteric lymph nodes are frequently hyperemic and edematous. Adrenal cortical hemorrhages, petechial, and ecchymotic hemorrhagic are often found on the peritoneum and pleura; also on the epicardium and myocardium. The changes are consistent with systemic gram-negative infections. 

1.4.1 Pathophysiology

Is speculative, local and systemic effects of endotoxin appear to have a significant role. Significant quantities of endotoxin are present in the lumen of the cecum and large colon of the equine, but are not absorbed into the circulation due to the impermeability of mucosal cells. The exact mechanism by which endotoxins gain access into the circulation are now known. Systemically, endotoxin induce depression, abdominal pain, fever,leukopenia, congested mucous membranes increase HR, and increased RR, arterial hypoxemia and mild transient diarrhea.

Endotoxin-like substances have been found in the blood of horses with clinical cases of colitis, both salmonella positive and negative. 

1.5 Therapy:

Example :

Horse 450 kg with decreased skin elasticity and PCV --> 60 can be estimated to be 8-10% dehydrated and would require at least 40 liters of fluids.


The type of fluids and amounts will be based on the frequent evaluation of electrolyte and acid-base status.

Lactated or Acetate Ringers solution can be given. Potassium can be supplemented in the form of KCL.


Horses that survive the first 72 hours of illness will usually require medical attention for 7-10