Tu bercidosis . 401 



and heavy milking, the retention in the herd of old, failing cows 

 for their milk product and high priced offspring, and the bovine 

 habit of licking each other with the infected tongue. In many 

 European cities and even in country districts the disease is very 

 prevalent. In Copenhagen a few years ago 17.7 per oent. of all 

 oxen and cows killed in the abattoirs were tuberculous ; in Berlin 

 15 percent. ; in Holland 20 percent.; in Pomerania and Bomberg 

 50 per cent. ; in Hildesheim, Hanover, 50 per cent. ; in Berlin 

 dairies 75 per cent. (Ostertag) : in Eeipsic and Edinburgh 20 

 per cent. The great variation in the data for the different cities 

 is suggestive of different inspection standards. American figures 

 as given by the Bureau of Animal Industry are for Baltimore 

 (mostly cows recently from the country) 2.5 to 3.5 per cent. ; 

 and for the packing centers (among 2,273,547 mostly fat steers, 

 and therefore selected) 0.02 per cent. It is here largely a matter 

 of locality and infection, I have seen large herds with 100 per 

 cent, tuberculous, and extensive districts, in the north and especi- 

 all)' in the south entirely free from the disease. 



Dogs a?id cats in their natural condition rarely show the disease, 

 but contract it readily on inoculation. Cadiot found 40 cases in 

 9,000 post mortems of dogs. The young are apparently more 

 susceptible than the old, and primary lesions in the abdomen are 

 common and suggest infection through the food. The majority 

 belonged to consumptive persons, and gnawed the bones that had 

 been first picked by the owner, and ate from his plate what he 

 left. Jacobi records the case of a dog, with general tuberculosis, 

 which habitually licked up the expectorations of his phthisical 

 master. 



Apes and Monkeys, in confinement, almost all die of tuberculosis. 



Swine contract tuberculosis readily, the large tonsils, the habit 

 of breathing through the mouth, and the abundance of connective 

 tissue and lymph plexuses in the lungs and elsewhere contributing 

 to this. Yet in them the affection is mainly a dietetic disease. 

 Swine kept in the country and fed on vegetable food are rarely 

 affected. In Saxony, where 17 per cent, of the cattle are tuber- 

 culous only a shade over one per cent, of swine were so, and in 

 Baden only 0.02 per cent. In hogs raised on our western farms 

 and corn-fed the proportion is much less. Yet in those fed on 

 uncooked skim milk, kitchen scraps and the refuse of slaughter- 

 26 



