Tuberculin sensitivity in a high-risk canine population.

An epidemiologic study of tuberculosis in dogs exposed to humans with recently reported tuberculosis was undertaken in Philadelphia between July 1966 and June 1968. A total of 29 dogs meeting the criteria for inclusion in the high-risk population were studied by history, physical examination, intradermal tuberculin tests, and radiographic and bacteriologic examination. Ten of the 29 dogs showed positive responses to US Department of Agriculture (USDA) standard mammalian tuberculin. Positive tuberculin tests to second strength PPD were demonstrated in five of the 10 responders to USDA mammalian tuberculin. No physical, radiographic or bacteriologic evidence of tuberculosis was found in any of the high-risk animals examined. In a comparison group of 70 dogs without knwon exposure to tuberculosis, two positive responses to USDA tuberculin were demonstrated and none to PPD.