A Novel Approach to Minimising Acute Equine Endometritis That May Help to Prevent the Development of the Chronic State

Abstract

One of the most commonly encountered challenges in equine breeding is endometritis, which can be difficult to resolve and causes considerable economic losses to the industry. It is a multifactorial condition, developing as an exaggerated form of the normal physiological response to breeding. Seminal plasma proteins, spermatozoa, bacteria and debris initiate an inflammatory response; the resulting fluid and neutrophils are then cleared from the uterus along with the debris. However, in some mares, the response is prolonged or exaggerated, with much fluid formation and neutrophil infiltration leading to acute endometritis. A bacterial cause has been implicated, although in some cases no pathogenic organisms can be isolated on culture. It has been postulated that any one of a variety of bacteria could be involved, or dysbiosis of the uterine microbiome could be responsible. Repeated episodes of acute endometritis may lead to the pathology associated with chronic endometritis, with mucociliary dysfunction, vascular degeneration and plasma cell infiltration. This review examines the information that is currently available about equine endometritis, particularly about the role of the inseminate in the uterus, and its current treatment. There are some promising lines of research into treatment or prevention that may help to resolve the issue.

Metagenomic analysis unravels novel taxonomic differences in the uterine microbiome between healthy mares and mares with endometritis

“…Endometritis continues to be one of the major causes of infertility in mares and the findings of this study could potentially serve as a basis for novel diagnostic and therapeutic approaches to address this important problem. As suggested recently by Morrell and Rocha (2022), the interactions among various microbes rather than the presence of a single microbial species may play an important role in maintaining uterine health. The diverse uterine microbiome detected in the present study makes a strong case for potential inclusion of metagenomic profiling in the diagnostic work-up of infertile mares.…”

Exploring the metabolome of seminal plasma in two different horse types: Light versus draft stallions

“…A possible explanation for controversial results on seminal plasma functions is that each insemination represents a unique set of semen and uterine conditions with a unique outcome in terms of sperm motility and uterine inflammatory response. Extending this concept, presumably each seminal plasma sample has a specific composition that can exert a unique response in the uterus depending on the combination of seminal plasma, sperm and uterine factors (Morrell & Rocha, 2022 ).…”

Metagenomic analysis unravels novel taxonomic differences in the uterine microbiome between healthy mares and mares with endometritis

“…mares and the findings of this study could potentially serve as a basis for novel diagnostic and therapeutic approaches to address this important problem. As suggested recently byMorrell and Rocha (2022), the interactions among various microbes rather than the presence of a single microbial species may play an important role in maintaining uterine health. The diverse uterine microbiome detected in the present study makes a strong case for potential inclusion of metagenomic profiling in the diagnostic work up of infertile mares.…”