THE DIGESTIVE SYSTEM. 287 



foodj certain acrid plants in a pasture^ even excess or sudden 

 changes of food. Sometimes when an animal is turned out 

 after being kept in a stall an attack comes on, also any ex- 

 posure to cold is a very fruitful cause, since thereby the ex- 

 cretory function of the skin is arrested, and extra work is 

 thrown on the internal organs, lungs, kidneys, and bowels. 

 Sometimes chronic diarrhoea results from long-continued 

 improper dieting, whereby the mucous membrane of the 

 alimentary canal becomes organically altered, and its 

 secretory function perverted. When calves are being 

 weaned they are very liable to become affected in this 

 way, and they have little strength of constitution to 

 enable them to withstand an attack. Indeed, in the 

 majority of cases of obstinate diarrhoea there is a debili- 

 tated state of the system which is a result of the flux, 

 but also proves an accessory cause. This explains the 

 obstinacy of the disorder. In diseases of the liver, and 

 it is said also of the pancreas, diarrhoea may be present. 

 When the flow of bile is excessive the evacuations become 

 dark -coloured, watery, and profuse. The presence of para- 

 sites is occasionally the cause, but in many cases diarrhoea 

 is merely an indication of blood disease. Thus, this is the 

 case in rinderpest, certain forms of anthrax, and notably 

 of scrofula, when either the mucous membrane of the 

 intestines or the mesenteric glands are affected. Sometimes 

 a relaxed state of the bowels occurs as a critical symptom 

 in disorders, of this ^' red water '^ is a notable instance. 



On post-mortem examination a general angemic condition 

 is found associated with congestive blush of the gastric 

 and intestinal mucous membrane, and perhaps the organic 

 changes which produced the disorder will be detectable. 



Treatment. — When called to a case of this disease we 

 must determine whether it be due to blood disease or local 

 irritation. In these cases it may even be advisable to pro- 

 mote it by administration of laxatives, preferably olea- 

 ginous agents. At the same time the patient should be care- 

 f ullynursed and stimulant tonics administered internally. In 

 all cases the diet must undergo a thorough change. Where 

 organic disease exists tonics must prove our main resource. 



