Investigations concerning bovine tuberculosis : with special reference to diagnosis and prevention / conducted under the direction of D.E. Salmon.
- Date:
- 1894
Licence: Public Domain Mark
Credit: Investigations concerning bovine tuberculosis : with special reference to diagnosis and prevention / conducted under the direction of D.E. Salmon. Source: Wellcome Collection.
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![instances. He was killed January 26,1893, and the post-mortem exam- ination showed extensive tuberculosis.* After the first tuberculin test of the bull had given a positive reac- tion and the excised glands had been found tuberculous, the view, which had been gaining strength for some time, that tuberculosis was very general in the herd assumed almost the character af a fact, and it was further supported by another careful examination of the cattle extend- ing over two days at the beginning of December, 1893. Several undoubted cases of tuberculosis were diagnosed, three or four times as many more animals were distinctly to be looked upon with suspicion. The condition of a very large portion of the remaining cattle was such that a diagnosis of tuberculosis with the methods usually employed by the practical veterinarian could not be made. Yet they showed little irregularities of various kinds which made it impossible, in the presence of so much tuberculosis, to pronounce them certainly free from the affection. With matters in this uncertain state it was concluded to seek more reliable results from a general tubercuhn test, and this was all the more desirable because the Bureau had been seeking a favorable oppor- tunity for some time to test the value of tuberculin as a diagnostic agent on a larger scale than had been previously possible. TUBERCULIN TESTS. A preliminary tuberculin test was made directly after the last exami- nation of the herd. Five cows were selected and their temperature taken every two hours from 6 a. m. to 8 p. m. December 6, 1892. The following morning at 6 o'clock each animal received an injection of tuberculin under the skin on the left side of the neck, and the tem- perature was again taken every two hours until 8 ]}. m., and once in addition to this at 9 p. m. December 8 the temperature was again taken at 11 a.- m. to determine whether it had returned to normal in the animals which had shown an elevation the previous day. (For the degrees of temperature, obtained per rectum, during the test, see table, p. 59.) The substance injected was the regular ^' Tuberculinum Kocliii imported from Germany. It was used in a 10 per cent solution. The diluent was distilled sterile water to which one-half per cent of carbolic acid had been added. Each animal received a dose of the solution equivalent to 0.4 cc. of pure tuberculin. The reactions following the injections Avere quite surprising, and implied the presence of even more tuberculosis than liad been sus- pected. Two of the cows selected, Nos. 30G and 311, which were included in the preliminary test particularly because of their excellent condition and apparently perfect freedom from disease gave high reac- tions. Cows Nos. 303 and 314 were selected as well-developed cases of * For the tuberculiu tests and the post-mortem notes see p. 58.](https://iiif.wellcomecollection.org/image/b21783111_0015.jp2/full/800%2C/0/default.jpg)
