The Breeding Soundness Exam (BSE) is the main tool veterinarians use to assess a mare’s reproductive health. This comprehensive evaluation helps determine the mare’s suitability for breeding to improves the success of breeding programs. [2][3]

The primary purpose of the BSE is to identify and correct any potential reproductive issues or anatomical abnormalities that might interfere with successful conception, maintenance of pregnancy (gestation), or the birthing process (parturition) in mares.

The BSE is key to identifying reproductive problems early, allowing for timely intervention and management. This increases the likelihood of a successful breeding and healthy pregnancy for both the mare and developing foal. [1][2][4]

Through this examination, horse owners and breeders can make informed decisions about breeding management, optimize reproductive efficiency, and contribute to the long-term sustainability of equine breeding practices. In this article, we’ll explore the steps involved in a routine breeding sounds exam in the mare, as well as possible findings.

Breeding Soundness Exams for Mares

Despite ongoing advances in equine husbandry and veterinary care, achieving a full-term pregnancy in mares can be challenging. The foaling success rate is often measured below 60%, underscoring the complexities involved in equine reproduction. [1]

Breeding soundness exams (BSEs) are important evaluations performed on both stallions and mares to assess their potential for successful breeding. This process is essential for maintaining and improving herd genetics, animal health, and the overall efficiency of breeding programs.

A BSE in the mare will typically include a general health assessment and examination of the reproductive tract. More in-depth evaluations may include an analysis of hormone levels and uterine culture or biopsy.

Benefits of a Breeding Soundness Exam

The main goal of the BSE is to assess the reproductive fitness of the mare and detect health issues that might affect her ability to conceive, maintain pregnancy, or give birth to a healthy foal. Additional reasons to perform a breeding soundness exam (BSE) in a mare include:

  1. Assessment of Reproductive Health: The BSE helps evaluate overall reproductive health, including the examination of the reproductive tract and assessment of the estrous cycle. This provides valuable insights into the likelihood of successful conception and pregnancy.
  2. Evaluation of Fertility: The BSE assesses the mare’s fertility status by examining factors such as hormone levels, uterine health, and ovarian function.
  3. Detection of Anatomical Abnormalities: The BSE helps identify any structural or anatomical abnormalities that might affect the mare’s ability to conceive, carry a pregnancy to term, or give birth naturally.
  4. Optimization of Breeding Management: It assists owners in making informed decisions about breeding management, including selecting suitable breeding methods and timing.
  5. Maximization of Reproductive Efficiency: By addressing any potential reproductive challenges early on, the BSE helps maximize the reproductive efficiency and minimizes potential financial losses associated with unsuccessful breeding attempts.
  6. Prevention of Disease Transmission: By screening for infectious diseases and genetic disorders, the BSE helps prevent the spread of sexually-transmitted diseases and ensures the production of healthy offspring.

When to Schedule a Breeding Soundness Exam?

It is recommended to schedule a BSE at the beginning of the breeding season before selecting a stallion or initiating any breeding protocols. This will ensure that a mare is healthy enough to undergo pregnancy and parturition, and allow you to address issues that could interfere with breeding.

However, if a mare has a history of successful conception, gestation, and parturition, she may not require an annual BSE unless she encounters difficulties during the breeding season. [2]

Other scenarios for which your veterinarian may recommend a BSE include:

  • Maiden Mares: First-time mothers (also called maidens) benefit from the general reproductive health assessment that a BSE offers. It is particularly recommended for maidens over 12 years old, as age-related changes to the cervix can negatively impact breeding and foaling. [4]
  • Aging Mares: Generally, a mare’s fertility begins to decline between 10 and 15 years of age, increasing the risk of pregnancy loss. [8] Senior mares have a higher risk of reduced fertility and age-related endometritis. [9]
  • Assisted Reproductive Technologies: Before investing time and resources on assisted reproductive techniques, it’s advisable to conduct a BSE to assess the mare’s suitability for these procedures. Techniques include artificial insemination, deep horn insemination, and embryo transfer.
  • Breeding Failure or Pregnancy Loss: If a mare experiences breeding failure and/or pregnancy loss, a BSE can help identify underlying problems. Examples include subclinical endometritis, fibrosis, or anatomical defects. [4]
  • Pre-Purchase Examination: For those considering the purchase of a broodmare, conducting a BSE as part of a pre-purchase exam is crucial. It ensures that the mare has the capacity to carry a foal to term, providing valuable information for prospective buyers. [4]
  • Postpartum Evaluation: Some owners opt for a BSE after a mare gives birth to assess the condition of her reproductive tract and check for any fluid or infection prior to rebreeding. [4]

Reproductive Anatomy and Physiology of Mares

Understanding a mare’s reproductive anatomy and physiology is crucial for making informed management decisions and enhancing her reproductive efficiency. Sever