IXTERCOMMUXICABILITY OF TUBERCULOSIS. 
819 
or the progeny of imported stock. Then, although for the most part 
cattle are never housed, they always, even when in large mobs, have 
favourite camping-grounds on which they congregate at night, and 
which become contaminated with infected droppings and discharges. 
The stagnant waterholes in the vicinity of these camping-grounds 
may at any time become contaminated, and facilitate the spread of the 
disease. A third factor in the spread of the disease in the past has 
been the indiscriminate way in which virus has been obtained to 
inoculate for the prevention of pleuro-pneuinonia. Tuberculous 
animals are very likely to become affected Avith pleuro-pneumonia, 
and stockowners (thousands of whom inoculate their own cattle) in 
many cases are as likely to obtain virus from a tuberculous animal as 
not/ Most important of all, however, is the fact that at least 90 
per cent, of all the cattle bred in Australia arc not slaughtered until 
they have arrived at or gone far beyond maturity. The females are 
kept for breeding until eight and nine years old. Bullocks are not 
slaughtered until at least four years old, the average age being six. 
When it is remembered that tuberculosis in bovines is mostly a disease 
of maturity or old age, it will be seen that the opportunities for its 
spread are very great, as each animal that becomes affected as age 
increases acts as a fresh centre from which the disease is communi- 
cated. Abattoir statistics endorse this, as it; is found that the disease 
is most common by far in bullocks — especially those from Queensland 
— up to seven, eight, and nine years old, and in old dairy cows. 
In Victoria, I am sorry to sav, any statistics which are obtain- 
able in reference to the disease in dairy and store stock are altogether 
unreliable. Mr. Pentland, Chief Inspector of Stocky furnished me 
with an estimate of the prevalence of tuberculosis in \ ictorian stock, 
based evidently oil the proportion between the numbers condemned 
annually by the stock inspectors and the number of. cattle in the 
colony. He put it at 1 in 300, or 3 per cent. This, in view' of 
abattoir statistics and the experience of myself and other veterinarians 
in private practice, I believe to be an absurdly lo.w estimate ; and the 
utter unreliability of the figures is easily explained when it is men-, 
tioned that the stock inspectors are laymen without training in sciem 
tific diagnosis, and in some cases lacking in anything more than two 
or three years’ experience of animal diseases. Again, it is evident 
that onlv a small proportion of the cattle of Victoria can be inspected 
by them annually, there being only six district inspectors m the whole 
colony. 
At the Melbourne city abattoirs the animals are subject to lav 
inspection on slaughter, amt during the existence of the Board of 
Inquiry on Tuberculosis in Cattle in Victoria some fairly reliable 
statistics were obtained. On these the board based the statement that 
“ probably, therefore, over 7 per cent, of all cattle slaughtered for the 
“ ” ” ire tuberculous iti some degree. lor the 
meat supply of Melbourne are tuberculo - . , 
half-year ended December, 1S84, of 10, 780 eattled slaughtered^ / 1 
percent, were affected, and for the half-year ended June, 18So, ot 
18,722 slaughtered, 4T per cent, were affected, or an average tor the 
year of 5 0 per cent. Of the total number slaughtered tor the year, 
however— viz , 35,502— only 113 were condemned as being untit lor 
human food, or a proportion of 1 in 314 It will be instructive to 
compare these figures with the returns for the six months ended 
