110 
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Tuberculosis in Birds. 
By Henry Gray, M.R.C.V.S., Kt-nsin^ton, W. 
By tuberculosis we urulei'stand a disease characterised by 
tubercles found in various organs of the body and due to the 
bacillus of tuberculosis, also called the bacillus of Koch, who 
isolated and demonstratetl it as the specific cause of the disease. 
All other nodular diseases not due to Koch's bacillus are termed 
false tuberculoses. 
This disease attacks all classes of birds as well as every 
class of animal, domesticated or wild, when kept in confinement. 
It even attacks fishes, reptiles and amphibia. But of the domest- 
icated animals it occurs more often in the ox than in any other. 
Next to the ox in relative frequency comes man, then the pig and 
afterwards the fowl, cat, dog, horse, rabbit, goat and, last of all, 
the sheep. The guinea-pig, although experimentally the easiest 
animal to induce it in, is rarely attacked spcmtaneously. The 
same might be said of the sheep, in which it does not appear 
si)outaneously in one in five hundred-thousand. Of the wild 
animals in confinement the monkey heads the list. 
Leaving out domestic poultry, the semi-domesticated fancy 
|)heasant, the parrot and perhaps the pen-reared partridge, tuber- 
culosis is a comparatively rare disease in wild birds kept in con- 
finement. When it does occur in them it is usually seen in a 
collection confined in a Zoological Garden or large out-door aviarj\ 
It may, however, be encountered in every variety of bird, even 
the carnivorous. The Ostrich is not exempt. It has also been 
discovered in a hawk at liberty. 
With the exception of the parrot it is oftener seen in the 
Gallinace* than in any other species. Perhaps in this case the 
method of feeding (from the ground) accounts for the frequency* 
In cage-birds, with the exception of the Parrot, it is a very rare, 
if not almost an unknown disease. It is not rare in them be- 
cause of their immunity but in consequence of the conditions 
under which most birds live in an isolated cage being unfavourable 
to its transmission. Experimentally they are very susceptible. 
On the contrary, the reason it is comparatively common in 
the jiarrot is because, on the one hand tliis tribe is more susceptible 
to mammalian tuljerculosis ; and, on the othei' the conditions for 
contamination are more favourable. 
[To be continued.] 
