Effect of repeated intrauterine infusions of gentamicin on the equine endometrium

Abstract

Nine Thoroughbred mares were used in an experiment to determine the effect of two intrauterine gentamicin infusions on the histologic reaction of the endometrium. Five mares had 40 ml gentamicin (50 mg/ml) mixed with 80 ml of normal saline infused into the uterus on two consecutive days. Four mares were used as controls and had 120 ml of saline infused into the uterus on two consecutive days. Endometrial biopsies were taken from all mares on Days 1, 3, 5, 8 and 13 after the second intrauterine infusion. Endometrial biopsies were scored for the presence of polymorphonuclear cells (PMNs) and mononuclear cells in the epithelium, stratum compactum and stratum spongiosum. Results were analyzed by logistic regression. There were significant differences in the inflammatory response by time (P<0.005), endometrial layer (P<0.005), and treatment (0.05 < P < 0.1). The inflammatory response was greatest 3 and 8 d after the saline infusion and 3 d after the gentamicin infusion. More inflammatory response was seen in the epithelium and stratum compactum than the stratum spongiosum. The gentamicin-treated mares had a less severe endometrial inflammatory response of shorter duration than the saline-treated controls.