124 THEORY AND PRACTICE 



In superpurgation we have diarrhoea, but it is not functional ; 

 it is the result of the action of the dose. 



Etiology. — Diarrhoea is caused by the action of some irritant 

 in the bowels. This irritant acts as a stimulant. Undue fermen- 

 tation may be present, brought about by specific germs, espe- 

 cially fungi and molds. Or there may be inactivity of the liver 

 in which there is a defective secretion of bile, — there is not bile 

 enough to ch-ange the acid chyme to the alkaline chyle. If the 

 contents of the bowel are not alkaline, then diarrhoea takes place. 

 This is the cause of 95 per cent of all the cases that occur. Par- 

 asites, various intestinal worms, especially the ascaris megaloce- 

 phala, tape worms, mechanical and chemical irritants, local irri- 

 tants such as would produce a local inflammation with alteration 

 of structure, excess of bile which is of itself a laxative (ox gall 

 was the old standard family laxative), bad hygiene (poor food, 

 such as hay cut from the bottoms which overflowed the previous 

 spring, the action of the sand that sticks to the grass and is eaten 

 with the hay being the cause of the diarrhoea ; foul water con- 

 taining wigglers and parasites-, and irregular and overfeeding), 

 exposure to cold and dampness, overheating especially on a hot 

 day and some forms of indiges-tion — these are the principal fac- 

 tors producing diarrhoea. Diarrhoea is also a symptom of in- 

 fluenza. 



S.emeiology. — In diarrhoea there is usually a watery discharge 

 from the bowels, often spoken of as alvine discharges. The 

 color is dirty brown or it may be clay or yellow. The dirty 

 brown is the usual color when the liver is not afifected. The 

 lighter color indicates a deficiency of bile, a yellow color an ex- 

 cess of bile. In case of an excessive secretion of bile there will 

 be a switching of the tail prompted by the irritating action of the 

 bile, which scalds the anus. This is bilious diarrhoea. 



In all cases of diarrhoea evacuations are frequent ; in mild 

 cases the discharge may be frequent too, but it is not so fluid. 

 There is more or less pain present, and in bad cases actual 

 cramps. If the case is acute the animal may lose a day or two 

 from his work. Increased secretion and increased peristalsis 

 are nature's remedies to get rid of irritants. Consequently in 

 diarrhoea we find the mouth pasty, like the coated tongue in the 



