AN OUTBREAK OF LEPTOSPIROSIS IN A SWINE BREEDING HERD : IT'S DIAGNOSIS, TREATMENT AND ECONOMIC EFFECT

Abstract

An outbreak of leptospirosis in a 2600 sow breeding herd, in which 5% of the sows aborted, was investigated. Serum samples from 11 aborted sows were examined for leptospira antibodies. Using a Microscopic Agglutination Test (MAT), containing only 12 serovars, no leptospira serovars were detected. However, after using a Microcapsule Agglutination Test (MCAT) kit, a further MAT using the additional three serovars (sejroe, hardjo and bratislava) revealed that the cause of abortion was Leptospira interrogan serovars bratislava and sejroe. After the final diagnosis, the animals were
treated by using 800 ppm chlortetracycline in the feed for two weeks, followed by two weeks at 600 ppm. This was combined with systemic antibiotic treatment to all affected and at risk sows and fever, anorexia and abortions ceased. Rats were eradicated and the feeding boxes in all pens were covered, as a preventive measure to control the disease. The economic losses from the outbreak were substantial and including fewer piglets weaned, the value of sows that had to be culled, the cost of medication and
the labour required to treat and control the disease. All of these factors have been reported in this study.