tubp:rculosis in the horse. 227 



In the horse, as in other species of animals, tuberculous changes 

 are sometimes generalised, sometimes — and most frequently — localised 

 in the thoracic or abdominal viscera. Analysis of the cases published 

 in France and other countries shows that the organs may be arranged 

 in the following order with regard to the relative frequence with which 

 they are affected : — lungs, bronchial glands, mesenteric and sub- 

 lumbar glands, mediastinal glands, spleen, liver, pleura, peritoneum, 

 intestine. The proportion of cases of pulmonary tuberculosis is about 

 70 per cent. ; of tuberculosis of the mesenteric and sublumbar glands 

 and of the spleen about 40 per cent. ; of the liver, pleura, and perito- 

 neum 20 per cent. ; of the intestine 15 per cent. Pleurisy has been 

 noted in about a fifth of the cases. Ascites is more rare. 



Tuberculosis of the kidney, though common in certain species, 

 especially in the dog, appears to be exceptional in the horse. The 

 pericardium, heart, bones, muscles, and other tissues are rarely affected. 

 I have seen only two cases of tuberculosis of the endocardium, two of 

 the pericardium, two of the bones, and one of the mammar}' gland. In 

 one of his reported cases Mauri mentions tuberculous lesions of the 

 pharyngeal glands, of the pharyngo-tracheal mucous membrane, and 

 of the endocardium. Wolstenholme claims to have seen several cases 

 of tuberculosis of the brain, but without furnishing any proof that the 

 lesions were really due to tubercle bacilli. In one case showing pulmo- 

 nary lesions and cavernous spaces, ossification of the right auricle of 

 the heart was noted. 



The changes in the thoracic organs, and especially in the lung, do 

 not always present the characters found in our patient. Sometimes 

 the pulmonary lobes are crammed with recent miliary granules, such as 

 may be seen in the other specimen. These granules are whitish or 

 yellowish in colour, dense, hard, and without central softening ; they 

 are dispersed throughout the entire lung, isolated in most instances, 

 confluent in a certain number, but always firm and unsoftened. In 

 general, the parenchyma of the lung in which they are embedded is of 

 normal colour and consistence. 



In other cases tubercles have developed in considerable numbers 

 in the connective tissue of the lung without producing signs of acute 

 inflammation. Here is a specimen of such tubercular infiltration. 

 The surface of sections appears almost entirely covered with whitish, 

 very dense masses of tubercle, irregular in outline, united by bands of 

 the same appearance and nature which run in all directions, inter- 

 twining and enclosing portions of apparently healthy or slightly hyper- 

 aemic parenchyma. You will note that such lesions are particularly 

 large towards the upper part of the lung. On bacteriological examina- 



