Diagnosis of endometritis in the mare: Reflections and evidence on methods and their results

Abstract

Endometritis is the most common cause of subfertility in mares; which may have a normal estrous cycle, but fail to become pregnant, or suffer early embryonic loss. The most frequent clinical signs of endometritis are free intrauterine fluid, excessive uterine edema, vulvar discharge, abnormal estrous cycles, among others. However, in the case of subclinical endometritis, the absence of these signs can make detection and diagnosis more difficult. There are a variety of sample collection methods, such as swab, cytobrush, uterine lavage, or biopsy, each covering a different range and depth of the endometrium and possessing different degrees of sensitivity and specificity. To evaluate these samples, different laboratory diagnostic methods such as endometrial cytology, culture and histopathology can be selected, which are used to evaluate the degree of inflammation or infection. The aim of this article is to discuss available evidence on sensitivity and specificity of the current sampling and diagnosis methods, and interpretation to arrive at an adequate diagnosis and treatment. In addition, new diagnostic techniques in equine reproduction practice will be presented.