The serological clostridium tumour test--application of discriminance analysis.

The microbiological tumour test is based on the detection of humoral antibodies to clostridial rods following intravenous injection of apathogenic clostridial spores. As serological methods we used the complement fixation test with a simultaneous short-time warm and long-time cold incubation as well as the passive haemagglutination test after absorption of clostridial group-specific antibodies. The evaluation of titre dynamics was rendered difficult by normal clostridial antibodies, by serological cross-reactions and, above all, by border-line reactions. The serological test results from 189 dogs investigated were evaluated in a multivariate analytical procedure. We determined the adequate combination of methods and antigens, thus improving the reliability of the test results and objectifying the predictive value of low sero-positive titres. On the basis of the computer-calculated individual weighting factors and the corresponding reference value it has become possible to evaluate and classify actual serological data emerging from the previous overall investigation.