TUBERCULOSIS IN THE HORSE, 233 



On post-mortem examination it became clear that the horse had died 

 from tuberculosis. The spermatic cords were swollen, indurated, and 

 covered with granulations. The liver, spleen, lungs, sublumbar and 

 bronchial glands, peritoneum, pleura, and pericardium all contained 

 numerous tubercles. The intestinal mucous membrane, and especially 

 that of the large colon, was crowded with ulcerations, most of which 

 were very rich in bacilli. The heart showed remarkable changes. 

 Large tracts of the endocardium of the left ventricle were thickened, 

 wrinkled, and contracted. Histological and bacteriological examina- 

 tion revealed the presence in it of tuberculous follicles containing very 

 few bacilli. Situated slightly below the aortic orifice in the muscular 

 tissue of the heart was a tuberculous abscess as large as a hazel-nut, the 

 pus from which contained numerous bacilli. 



A dog, a rabbit, two guinea-pigs, and two fowls were intra-peri- 

 toneally inoculated with an emulsion prepared by crushing a fragment 

 from a sublumbar lymphatic gland and a tuberculous growth from the 

 gastro-colic omentum in a little sterilised water. The dog, rabbit, and 

 guinea-pigs became tuberculous, the fowls resisted. 



Bearing in mind the varying forms which tuberculosis may assume 

 in the horse, it is rare that some of the complex assemblage of 

 symptoms fails to suggest the correct diagnosis. The final conclusion 

 is assisted by auscultation, percussion, rectal exploration, and palpation 

 of accessible lymphatic glands, and is confirmed by bacteriological 

 examination, injection with tuberculin, or inoculation. 



The clinical signs suffice to differentiate tuberculous inflammation 

 of lymphatic glands from the simple form (adenitis) ; in the latter the 

 swellings are always numerous, generalised, bilateral, and nearly 

 uniform in each of a pair of glands. 



Injection of 30 centigrammes of tuberculin is followed in tuberculous 

 horses by a reaction, which usually attains its maximum about the 

 fifteenth hour, the temperature rising 2 to 3 degrees C. In the stable 

 attached to the surgical clinique you have seen a horse retained for 

 experiments which developed tuberculosis after a double intra-peri- 

 toneal and subcutaneous injection of tuberculous material from a dog. 

 After the lapse of more than a year tuberculin still produces a febrile 

 reaction of i to 2*5 degrees C. 



At the present moment there is no treatment for tuberculosis in 

 large animals : diagnosis is followed by slaughter. The veterinary 

 surgeon's function is limited to recognising the clinical forms and the 

 anatomical and pathological appearances. 



