Diagnosing Tuberculosis.

Kaipara and Waitemata Echo, 27 November 1914, Page 3

Diagnosing Tuberculosis.

1 Is there more than one tuberculin test in use ;if so, how many ? What is the difference, if any, between the intradernal' test and thermal test ? Are there any other diseases or conditions, other than being infected with tuberculosis, that will cause a cow to react ? it lias been said that an infected herd may be treated to prevent any reaction ; is that a fact ? Thus writes a correspondent to "Hoard's nainman" U.S.), and that paper answers as follows :— There are three methods of diagnosing tuberculosis—the opthalmic, the intradermal, and the thermal test, the latter being the most common. The opthalniic test consists of putting a small quantity of tuberculin in the eye of the cow to be tested. The tuberculin is diluted or ; a salve is made of it. In eighteen hours or less, if the animal be tubercular, there is shown a. marked inflammation of the membranes of the eye and a slight discharge. If the animal is free fromtuberculosis these symptoms, will not arise. The intradermal test consists of injecting into the folds of the skin on one side of the tail a small quantity of tuberculin. The injection is made here as the location offers an opportunity for a comparison with the opposite side. The injection must be made into the skin, not under. If the animal be tubercular, within forty-eight- hours after the injection there will appear a marked . swelling, and the animal will display a characteristic switching of the tail.- If the animal is not tubercular these symptoms will not appear. . . The thermal test is the ordinary test. The temperature of the animal is taken at three-hour periods at least three times before tuberculin is injected. Eight or nine hours after the injection the temperature is taken every two hours, until the twentieth hour. A rise of 2de,g. above the maximum temperature taken before the injection constitutes some positive evidence .of tuberculosis. This is especially -true if the rise in temperature is slow and drops slowly. There are many disturbances or conditions which will cause a rise in temperature. Animals to be tuberculin tested should be in normal condition. If suffering from disease of any kind, the test must not be made until the animal is well. A tubercular herd may be treated so that it will not react to the tuberculin test. This is accomplished by injecting tuberculin into the animal prior to testing. Injecting a dose of tuberculin any time within a month for testing purposes will not give any reaction, even though the animal be tubercular. It is for this reason that it is advocated that animals be re-tested in about ninety days after applying the test. This gives an opportunity for the tuberculin to get out (V the system of the animal.