Endometrial lipogranulomas in a mare

Summary Lipogranulomas are localised tissue reactions to exogenous or endogenous lipids. This case report describes and depicts, grossly and histologically, the unusual finding of lipogranulomas in the uterus of a mare. Hyperechogenic areas were noted in the uterine body during routine ultrasonography of the reproductive tract; investigative hysteroscopy showed yellow‐white, nodule‐like structures in the corresponding regions of the uterus. They were biopsied, and histopathology confirmed the presence of lipogranulomas. The mare subsequently conceived and delivered a healthy foal after a gestation length of 330 days. Hence, the lipogranulomas, chiefly in the uterine body, did not appear to be detrimental to the mare's ability to conceive and carry a foal to term. In the absence of any endogenous factor known to cause lipogranulomas in other species, namely, systemic disease, trauma or a high intake of dietary fats, the most likely cause was exogenous lipids introduced into the uterus following an intrauterine antibiotic treatment containing enrofloxacin and amoxycillin in an oil‐based cream vehicle. It is hypothesised that damage to the endometrium caused by enrofloxacin allowed lipids in the vehicle to cause a reaction in the underlying tissue, resulting in the development of lipogranulomas.