At the present time there is ample evidence to show that tuberculin is the most reliable means of detecting tuberculosis in the living animal and that its use is not attended by any harmful aftereffects.
An act of Congress was approved July 24, 1919, for the purpose of controlling and eradicating tuberculosis of animals. The official means of detecting tuberculosis in the living animal is the tuberculin test, which may be applied by three different methods—the subcutaneous, the intradermic, and the ophthalmic. It is not necessary to discuss here the details of these three methods, which are made use of in the work of eradication of tuberculosis.
The plan adopted by the State and Federal authorities in eradication of the disease is known as "The Accredited-Herd Plan." Under this plan herds are tested under State and Federal supervision, the diseased animals are appraised, removed, and slaughtered under Federal inspection. Retests are then made after definite periods of time until two successive tests show all the animals to be free from the disease. At this time the herd owner is given a certificate of an accredited herd.
Details concerning the accredited-herd plan may be obtained by applying to the Chief of the Bureau of Animal Industry, Washington, D. C.
THE TUBERCULIN TESTS.
Testing animals with tuberculin is the process of introducing tuberculin into the animal and interpreting results according to well-known standards.
From the investigations and observations that have been mentioned, it may be safely concluded—
1. That the tuberculin test is a wonderfully accurate method of determining whether an animal is affected with tuberculosis.
2. That by its use the animals diseased with tuberculosis may be detected and removed from the herd, thereby eradicating the disease.