THE TUBERCULIN TEST. 
535 
of the contagion. A great many breeders and dairymen have 
suffered large losses in this State by bringing an infected animal 
into their herds. The Clap herd of Guernseys, which were dis¬ 
persed, carried infection into over 20 herds, as far as known. 
There has been much said about the susceptibility of dif¬ 
ferent breeds of cattle to contract the disease. I do not think 
there is any difference in regard to the different breeds if they 
are subjected to the same conditions and same source of con¬ 
tagion. Cattle that are housed most of the time with one that 
is affected will more readily contract the disease, as the ba¬ 
cillus raised in the pus from the lungs will readily dry and be 
disseminated and taken through the air passages or food. While, 
on the other hand, light or heat or severe cold will render the 
bacillus inert. You are very apt to find reacting animals on both 
sides of one badly affected with pulmonary tuberculosis for from 
two to three animals each way, if the animal is stationed near 
the middle of the row, and in other cases no other reacting ani¬ 
mals in a herd of 40 or 50. 
The proudest breeders in the State to-day are the ones that 
have had their herds tested and the diseased ones disposed of, 
and well they may be. They can sell any animal for breeding 
purposes to a neighbor and feel that they are not endangering 
the herd of the same to the contagion, or a milch cow, or milk, 
or the product of their dairy, without feeling that they are en¬ 
dangering the lives of any family. There is no question but 
that the contagion is carried by milk, and is communicable from 
bovine to man and from man to bovine. 
I found one cow with affected udder and held post-mortem 
upon two of her calves, one eight months old and the other a 
year and a half. I found both calf and yearling badly affected 
along the abdominal viscera and one in the glands of the thor¬ 
acic cavity and one lung. They had all reacted to the tuberculin 
test. It is not absolutely necessary to slaughter an animal in 
the incipient stage of the disease, but as you can never tell at 
what time they arrive at the point of spreading the contagion, 
I think it is better in most cases to dispose of them at once. 
