[Leptospirosis in slaughter cattle--serologic and bacterial study].

Antibodies to leptospiras were demonstrated in 91 cases (7.4%) out of 1,239 animals examined by serological assays of blood sera of cattle slaughtered in slaughter-houses and coming from 21 farms of one district. The antibodies were detected in animals coming from eleven out of the farms investigated (52.4%). The most frequent reactions were proved with leptospiras of the serovar L. grippotyphosa (61.8%) and with leptospiras of the serological group Sejroe (18.9%), rarely with leptospiras of the serovar L. icterohaemorrhagiae or copenhageni (5.7%). Antibodies to leptospiras of other serovars (L. canicola, L. bulgarica and L. hardjo) were demonstrated only as coagglutionations with the above-mentioned leptospira serovars. We failed to demonstrate leptospiras in the animals examined by culture examinations as well as by bacterioscopy. The results of examinations have shown that the cattle on Czech farms is also exposed to infections by various serovars of leptospiras. The infections are not accompanied by manifest clinical symptoms in many cases nor do they cause significant elimination of leptospiras in urine in the serologically positive animals. On the Czech cattle farms the occurrence of antibodies to leptospiras of the serovar L. grippotyphosa is prevailing; this serovar seems not to be expressly pathogenic to cattle and does not cause the formation of anthropurgic foci. Reduction in the occurrence of antibodies to leptospiras of this type is possible to achieve by preventing the contact with natural foci of this type. Hence the prognosis of epizootologic situation in bovine leptospirosis in the conditions of this country is relatively favorable. But special attention should be paid to animals bought and imported from foreign countries. These animals could be a source of some highly pathogenic serovars of leptospiras to cattle.