Inflammation and fertility in the mare

Area of Science:

• Veterinary Immunology
• Reproductive Immunology
• Equine Reproduction

Background:

• Post-breeding uterine inflammation is a normal mare physiological response, crucial for clearing bacteria and spermatozoa.
• A delicate balance of pro- and anti-inflammatory factors resolves this inflammation within 24-36 hours in healthy mares.
• Susceptible mares can develop persistent endometritis, a condition that threatens pregnancy establishment.

Purpose of the Study:

• To review current knowledge on uterine inflammatory and immunological responses to breeding-induced endometritis in mares.
• To summarize findings on persistent breeding-induced endometritis (PBIE) and bacterial endometritis.
• To highlight the need for understanding disease progression for improved treatment and management.

Main Methods:

• Literature review of current research on equine endometritis.
• Analysis of inflammatory and immunological responses to breeding stimuli.
• Examination of factors contributing to susceptibility to persistent infection.

Main Results:

• Persistent endometritis can stem from bacterial or semen-induced causes, both impacting fertility.
• Identified susceptibility factors include altered innate immunity, reduced myometrial contractions, and impaired opsonization.
• The precise pathogenesis of susceptibility requires further elucidation.

Conclusions:

• Further understanding of the mechanisms underlying persistent endometritis is essential for effective treatment and management in mares.
• Research is focusing on early inflammatory responses and potential immunomodulatory treatments.
• Addressing the immunological and inflammatory challenges in equine reproduction is critical for fertility outcomes.