Clinical Management of Endometritis in a Mare: A Case Report

Equine endometritis is an inflammatory condition of the uterus mainly caused by contamination of the uterine lumen with microorganisms, debris, or abnormal substances, which may originate from pathogenic bacteria, reproductive tract defects (such as pneumovagina and urovagina), poor perineal conformation, or unhygienic management practices during breeding and parturition (LeBlanc, 2010; Brinsko, 2011; Christoffersen and Troedsson, 2017). It is a complex disorder involving both physiological and pathological responses; normally, mares develop a transient inflammatory reaction after breeding (acute post-breeding endometritis) that clears contaminants within 24-48 h, creating a favourable environment for embryo survival (Morris et al., 2020). However, failure of this clearance mechanism leads to persistent forms such as persistent post-mating endometritis or chronic infectious endometritis, which impair fertility and increase embryonic loss (Malschitzky et al., 2003; Brinsko, 2011). Since the embryo enters the uterus around 6-7 days post-ovulation, timely resolution of inflammation is essential, as prolonged inflammation characterized by uterine fluid accumulation and cytokine activity reduces embryo viability (Robertson et al., 2018). Diagnosis of endometritis in mares is commonly achieved through ultrasonography, uterine cytology, microbial culture and in some cases, endometrial biopsy. Therapeutic management typically involves uterine lavage, administration of appropriate antimicrobial agents, use of ecbolic drugs to enhance uterine clearance and correction of predisposing anatomical defects, such as performing Caslick’s surgery (Samper, 2009; Dascanio and McCue, 2014). Overall, effective management depends on early diagnosis, proper hygiene and targeted therapeutic strategies to improve reproductive efficiency in mares (LeBlanc, 2010; Scoggin, 2016). This document reports on the successful clinical management of endometritis in a mare.