56 KENNEL DISEASES. 
like, the prevalent belief is that these influences cannot of themselves cause 
tuberculosis, but are capable merely of rendering the tissues susceptible to the 
invasion, and favorable to the growth of the microbe in question. In other words, 
a healthy lung does not attract this germ, nor are its conditions right for propa- 
gation. On the other hand, a lung that is not healthy, because of the unfavor- 
able influences mentioned, is good soil for the bacillus, and in it that germ will 
thrive and multiply. 
It is held by some that tuberculosis in the dog is an extreme rarity ; but this 
notion has been ably refuted by investigators, one of whom has reported that out 
of 7,000 dogs examined 27 were tuberculous, or 1 in 250. It has also been dem- 
onstrated that in these animals the lungs are the organs most frequently affected; 
and after them come the liver, serous membranes and kidneys. 
It may, moreover, be accepted that the direct cause of this disease in dogs is 
the same as that of tuberculosis in man, for the bacilli in both are identical. 
Furthermore, since in not a few instances dogs belonging to tuberculous people 
have died with tuberculosis, it is fair to assume that they were directly infected 
by those people. 
Considering certain natural peculiarities, their great lung powers and tenden- 
cies to keep them vigorous by exercise, it may indeed be accepted that tubercu- 
losis is never likely to occur among dogs unless they acquire the disease from the 
human family. And even when exposed to it, if they are much at liberty, their 
quarters are healthy, and food sufficient in quantity and wholesome, the danger 
of infection is very slight, because their lungs and other vulnerable parts of their 
systems will resist the bacillus of the disease. On the other hand, if dogs under 
unhygienic influence are exposed to tuberculous people, their chances of “taking” 
the disease are very much greater. 
For the purpose of illustration, it is assumed that the dog is a toy and his mis- 
tress a victim of this grave malady. He has but little exercise, is over weight, 
and otherwise his powers of resistance against disease are decidedly below the 
normal. Much of the time he passes on the bed of the patient. He is given her 
food remnants, and laps her plates and saucers. All these must, of course, be 
more or less contaminated with the bacilli of her disease, either through her lips, 
spoons, forks, or possibly knives. Her sputa may now and then drop on the 
floor, and the chances are that he laps it. Beyond this, a great pet and company 
for his poor mistress in long weary hours, he doubtless “kisses” her often. He 
also sleeps in her arms at times and breathes the expired air loaded with the 
microbes of her disease. 
Assuredly a dog so placed would likely be directly infected with tuberculosis, 
either through his alimentary canal or respiratory passages; and if he failed, 
wasted away, and followed his mistress to the “ great unknown” within a year, the 
conclusion would be justified that he had succumbed to the same disease. 
Indeed, dogs should never be admitted to the rooms of persons suffering from 
