Fishes. Broussais records the prevalence of tuberculosis in carp in a pond which received the sputa of a consumptive man. Under the skin were found rounded tumors, containing abundance of bacilli, that infected rabbits and Guinea pigs on which they were inoculated.
Birds. In birds of the farmyard—hens, pheasants, turkeys, ducks and pigeons—it is very frequent and often occurs as an epizoötic. While the tuberculosis of barnyard fowl is a manifest variety and not readily interchangeable with the varieties affecting the mammal, yet, with a special predisposition, it can be transferred and can then be conveyed from animal to animal in the new genus in which it has been implanted. That of cage birds is interchangeable with that of man.
Rodents. Guinea pigs have a strong susceptibility to tuberculosis, whether from human or bovine source, and rabbits for that of birds, and by continuous transmission through the body of the rodent, all alike seem to tend toward acquiring common characters. The Guinea-pig, therefore, has been especially availed of for the experimental transmission of tuberculosis, and, as the disease in them becomes acute and rapid in its progress, these subjects permit the multiplying of experiments in a short period. Rabbits are less vulnerable to the bovine or human form.
Sheep and goats, kept under usual conditions, show a remarkable immunity from tuberculosis, yet if directly inoculated an inherent susceptibility is easily shown. Habitual immunity may be in some degree due to their open air life, to the heavy winter fleece protecting them against chills, to the comparative absence of the heavy and continuous milk yield demanded of cows, to the more restricted development of the lymph plexuses in the lungs and elsewhere, and to the limited opportunity offered by the small tonsils for infection entrance.
The horse, ass and mule rarely contract tuberculosis casually, the more spacious stall, outdoor life, hard muscular condition, the very small tonsils, the exclusive nasal respiration, the paucity of connective tissue lymph plexuses, and the abundance of red globules, probably favor immunity. Yet on inoculation by Chauveau, Nocard and others, the horse readily succumbed to infection, generalization taking place more certainly than in the ox.
Cattle. The bovine races are remarkably subject to tuberculosis. This is probably due in part to the great amount of connective tissue lymph plexus in the lungs and elsewhere, the habit of using the mouth in hurried breathing, the deep, sudden inspiration through the mouth and over the tonsils that follows a cough, the habitual restricted size of the cow stables, the absence of individual separated stalls, the habit of feeding from the same trough with the cattle adjacent, the great drain of yearly breeding 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 cent. of all oxen and cows killed in the abattoirs were tuberculous; in Berlin 15 per cent.; in Holland 20 per cent.; in Pomerania and Bomberg 50 per cent.; in Hildesheim, Hanover, 50 per cent.; in Berlin dairies 75 per cent. (Ostertag): in Leipsic 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 especially in the south entirely free from the disease.
Dogs and 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 tuberculous 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 slaughterhouses in a raw state, tuberculosis becomes very common. In one case, in a large public institution, where the dairy herd was universally affected, and where, on their slaughter, their raw offal had been thrown to the hogs, I found that the latter were almost all tuberculous. Similarly, in feeding experiments, from the time of Gerlach, pigs and especially young pigs, have shown themselves to be very susceptible.
Among the less domesticated animals that contract tuberculosis may be named deer, elk, gazelle, antelope, camel, dromedary, giraffe, kangaroo, lion, tiger, jackal, jaguar, bear, arctic fox, rat, mouse and the common cage birds, etc. Fröhner found 36 per cent. of parrots affected in Berlin.