[Evaluation of the specificity of skin allergy tests in cattle with IBR-IPV]

An allergic and serologic investigation was carried out by the skin allergic test (SAT) and the virus neutralization test (VNT) to demonstrate the presence of infectious bovine rhinotracheitis -- infectious pustular vulvovaginitis (IBR-IPV) in cattle divided into three groups according to age, treated with the live attenuated vaccine MK25 against Aujeszky's disease. It was found that this vaccine induced the production of specific antibodies against the virus of IBR-IPV, which could be demonstrated through VNT (beta-variant) in low titers (2-2.5 log10), while through VNT (alfa-variant) no specific antibodies could be found. On the other hand, the virus of Aujeszky's disease did not usually lead or on very rare occasions (massive virus doses and continuous antigenic challenge) led to allergization of the body of cattle for IBR-IPV as well as to a positive SAT. Out of a total of 30 investigated calves only one proved positive by SAT, and 2 others were suspected of being carriers of infection. The problem is discussed of the specificity of SAT and its diagnostic value in IBR-IPV under some epizootiologic circumstances.