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Experimental Leptospira borgpetersenii serovar hardjo infection of pregnant cattle
Author(s) -
SMITH CR,
McGOWAN MR,
McCLINTOCK CS,
CORNEY BG,
KETTERER PJ,
SMYTHE L.,
WARD W.
Publication year - 1997
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1997.tb15663.x
Subject(s) - serotype , leptospira , leptospirosis , biology , cattle diseases , veterinary medicine , microbiology and biotechnology , virology , medicine
Objective To observe the effect upon the foetus of experimental infection of pregnant cattle with Leptospira borg‐petersenii serovar hardjo . Design A disease transmission study using pregnant cattle. Procedure Fourteen heifers serologically negative to L hardjo were artificially inseminated and later challenged with a north‐Queensland isolate of L hardjo by conjunctival inoculation. The heifers were serologically monitored and their urine examined for the presence of leptospires using culture and fluorescent‐antibody tests at appropriate intervals. Elective caesarean sections were performed on pregnant heifers at 6.5 weeks after the challenge. Foetuses were examined using serological, histopathological, microbiological and fluorescent‐antibody tests. Results Ten of the heifers became pregnant, but three subsequently aborted before challenge. After challenge, all 14 heifers seroconverted and L hardjo was isolated from the urine of 6 of the 7 pregnant heifers. No evidence of foetal L hardjo infection was detected. Two of the foetuses had histopatho‐logical lesions consistent with Neospora s p infection. Conclusion It is likely that the isolate of L hardjo used in this study does not normally infect the foetus. Neospora s p may be a more significant cause of bovine reproductive wastage.