TUBERCULOSIS 147 



that we are somewhat limited in our diagnostic ability 

 in diseases that affect the liver. 



We have seen postmortem demonstrations on cattle 

 which were apparently in the "pink of condition" dur- 

 ing life, showing a liv*er fairly rotten with tubercular 

 invasion. 



Tubercular involvement of the intestinal mucosa, es- 

 pecially of the terminal portion, is frequently the 

 cause of a persistent, or recurring, diarrhea. 



This diarrhcea is marked by the fact that it pro- 

 duces none of the common by-effects of benign or 

 non-specific diarrhoeas. Although it may persist for 

 days, there is no apparent abdominal pain nor any 

 distinct sign of derangement in the alimentary tract. 

 The evacuations are evidently the result of the irri- 

 tation accompanying certain stages of the pathological 

 processes taking place in the hindermost gut. 



If a rectal examination is made in these cases it is 

 usually no difficult matter to detect great numbers of 

 pea-sized nodules, many of them undergoing degen- 

 erative changes. It is probably as a result of these 

 changes of a degenerative character that the diarrhoea 

 occurs. Mucus, streaked with blood and occasionally 

 blood-clots, can nearly always be detected in the feces 

 in diarrhoea of this form. 



Cases of slowly developing ascites in cattle, not re- 

 ferable to any demonstrable causative factor, may al- 

 ways be suspected as being of tuberculous origin. It is 

 barely possible that some of these can be attributed 

 to interference with the portal circulation from ex- 

 tensive tuberculous involvement of the liver. Usually, 

 however, there is a distinct tubercular involvement 

 of the peritoneum which can often be detected by 

 careful rectal examination in the form of numerous 

 nodules or pearls. 



