A retrospective study of the causes of equine abortion occurred in southern Rio Grande do Sul, Brazil, diagnosed from January 2000 to June 2011 by the Regional Diagnostic Laboratory (LRD) of the Veterinary School, Federal University of Pelotas (UFPel), is reported. Necropsy protocols were reviewed, and from 1.154 horses or equine materials received 72 (6.2%) were abortions. The main cause of abortion in this study was bacterial infection on 36.1% of the cases. Non-infectious causes accounted for 8.3% of the cases, viral abortions for 4.2%, parasitic for 1.4% and inflammatory for 2.8%. In 47.2%, it was not possible to determine the cause/etiology of abortions. Characteristic macroscopic and histological lesions were observed in abortion by Leptospira sp. and equine herpesvirus-1. No lesions were observed in the other cases. It was demonstrated that the analyses of whole fetus with the placenta under refrigeration increases the efficiency of diagnosis. The high number of abortions of undetermined cause was attributed in part to inadequate delivery of fetus material for diagnoses.
Abortion; horses; infertility; feto-placental infection
