TUBERCULOSIS. 333 



sounds may be heard in the chest on auscultation. If the con- 

 tents of the abdomen are the seat of the disease, there may be 

 frequent attacks of colic, with constipation or diarrhoea. Nocard. 

 has observed a very pronounced diaodes insipidus and irregular 

 variations of temperature, but polyuria is not at all a constant 

 symptom in my experience, llemarkable to relate, all recorded 

 instances in the horse have been isolated ones, though the 

 animal may be one of a large stud. Is it possible that in the 

 horse the virulence of the bacilli becomes destroyed, and the 

 disease thus rendered non-infectious ? 



The tuberculin test may be applied to the horse as well as to 

 cattle. In the majority of cases observed by the author, the 

 spleen and mesenteric glands were the seat of the lesions ; the 

 liver, lungs, and bronchial glands being less frequently involved. 

 In some instances the spleen has been enormously enlarged, 

 and studded throughout its substance with grey translucent, 

 yellow-cheesy tumours ; whilst in the liver, lungs, and kidneys 

 similar growths are seen, but are caseous in their centres if 

 truly tubercular. Those tumours found in these organs and con- 

 sisting of white, round, firm succulent tissue, invading the 

 glomeruli of Malpighi and free from bacilli, are not to be con- 

 sidered tubercular ; they are those of lympho-sarcoma, having 

 some degree of organisation ; whereas tubercle is incapable of a 

 higher organisation than the grey nodule, is prone to rapid decay, 

 retrogressive changes commencing in the centre of the nodule, 

 and, the caseous material being the product of the death of the 

 cell elements, the surrounding growth is simply the hyperplasia 

 of the normal tissue, due to the invasion of the bacilli ; in fact, 

 an effort to erect a barrier to the further inroad of the attacking 

 bacilli. 



TUBEKCULOSIS OF THE PIG 



Is much less frequently met with than in horned cattle, the aver- 

 age, according to statistics, varying from 1*34 to I'di per cent in 

 Saxony, a little more than 10 per cent, in Amsterdam, "04: at Eouen, 

 •02 in the Duchy of Baden. In some districts it is never seen, and 

 in Scotland it is so rare that at one time I was inclined to think 

 the pig was immune. I have, however, observed it, and reported 

 the results of the tuberculin test to the Eoyal College of Veteri- 

 nary Surgeons ; and in which one of the most prominent symjD- 

 tums — not mentioned by authors — was an eruption of small 



