TUBERCULOSIS. 



389 



TUBERCULOSIS OF CATTLE. 



In cattle the disease may occur as the result of inhaling bacilli, 

 or of ingestion with food. It is very frequently found in the lungs ; 

 :ind calves may be infected by milk from cows with tubercular 

 udders. Calves may also suffer from congenital tuberculosis, the 

 bacilli having been transmitted from the mother during gestation. 



Breeding in-and-in, over-production of milk, and confinement with 

 insanitary surroundings, predispose to tuberculosis. The disease is 

 known in Germany as ^ Perlsucht"; and in this country the lesions 

 on the pleura are known [as 

 "grapes," and the animals 

 themselves are commonly 

 called " wasters." 



The disease may also exist 

 in the lungs or in other 

 organs, in a limited form, 

 without any indication of 

 ill health. In such cases 

 the disease can be detected 

 by injection of tuberculin, a 

 marked rise of temperature 

 occurring in tubercular 

 animals. 



In advanced cases, the 

 symptoms commonly observed 

 are cough, difficulty in breath- 

 ing, staring coat, wasting, and 

 diarrhoea ; and if the udder is infected, nodules in the gland, and thin 

 bl uish milk. In the lungs, after slaughter, a few small cheesy tubercles 

 may be found in animals apparently in perfect health and in prime 

 condition for the market. In advanced cases, the lungs on section 

 show large yellow masses, containing calcified matter, and the 

 bronchi may be full of yellowish pasty contents. The disease will be 

 found to involve the bronchial glands. The serous membrane may 

 be covered with little warts or grape-like masses. The lymphatic 

 glands may be enlarged to an enormous size. Tubercular ulceration 

 of the intestine is sometimes found, but not commonly. In tubercular 

 disease in the udder, a painless swelling is found which may affect 

 one or more quarters of the gland. 



Transmission of Tuberculosis from Man to Cattle. It is 



FIG. 170. SECTION OF LUPUS OF 



x 700. Giant cell containing a tubercle 

 bacillus (FLUGGE). 



