Lyme disease antibodies in thoroughbred broodmares. correlation to early pregnancy failure

Abstract

Summary A serological enzyme linked immunosorbent assay (ELISA) for equine antibodies to Borrelia burgdorferi , the causative agent of Lyme disease, was utilized on three groups of Thoroughbred mares 14 days after breeding. Group A mares were located in Kentucky, Groups B and C mares were in Florida. Group A were broodmares from a breeding farm, where early embryonic losses were reported by the farm to be substantially higher than previous years. Of 78 mares a total of 19 (24%) had experienced early embryonic resorption. The early embryonic loss rate was 47% (8/17) in the seropositive group and 18% (11/61) in the seronegative group. The excessive loss rate in the Lyme positive group was statistically significant, with the Chi-square test yielding a p value of .014. Group B had 51 mares that did not conceive on the first breeding; Group C consisted of 51 mares that became pregnant on the first breeding, and maintained pregnancy for at least 60 days. Group C was age and farm matched to serve as controls to Group B. Group B showed a higher incidence (22%) of elevated concentrations of antibodies against B burgdorferi , than did Group C mares (16%).