Stallion Breeding Soundness Exam

What is a Stallion?

• Definition: An uncastrated adult male horse.

Breeding Soundness Exam (BSE) for Stallions

• Purpose of BSE: A thorough examination of a stallion’s reproductive health to determine fitness for breeding and identify potential issues affecting pregnancy.

  • Checks fertility and identifies reproductive issues.

  • Evaluates several aspects:

  • Overall health

  • Mating behavior

  • Reproductive organs

  • Semen quality

• Breeding Criteria: A satisfactory breeder should impregnate at least 75% of mares (~30 out of 40 by live cover or 90 out of 120 by artificial insemination).

When Should a Stallion Have a BSE?

• Situations for conducting a BSE:

  • Pre-purchase or post-purchase check-up.

  • Pre-breeding season (60-75 days prior).

  • When suspecting fertility issues.

  • When considering a young stallion for breeding.

Uses of a BSE Exam

• Estimation of Future Reproductive Potential: Helps predict a stallion's future breeding capabilities.

• Routine Evaluation: Essential initial assessment for potential buyers.

• Diagnosing Reproductive Issues: Determines causes of poor reproductive performance.

Steps of the BSE Exam

Step #1: Identification of Stallion

• Important Information:

  • Registered name, registration number, age, breed.

  • Coat color, markings, lip tattoos, microchip information, brands, scars.

Step #2: Health and Breeding History

• Health Aspects:

  • Vaccination history, focusing on Equine Arteritis Virus vaccination.

• Breeding Aspects:

  • Previous BSE results and number of mares bred per season.

Step #3: Venereal Disease Testing

• Stallion must be free of common venereal diseases:

  • Equine Viral Arteritis (EVA)

  • Contagious Equine Metritis (CEM)

  • Equine Herpesvirus (EHV)

  • Equine Infectious Anemia (EIA)

  • Dourine

• Testing Method: Swabs collected from urethral fossa, urethra, penis shaft, prepuce.

Step #4: General Physical Examination

• Body Condition Score (BCS): Evaluated to ensure good health.

• Routine Physical Exam: Rules out medical issues that might be passed to mares.

• Breeding Performance & Conformation: Evaluates vision, heart, lung function, locomotion.

• Heritable Conditions: Stallions with heritable conditions should not be selected for breeding to avoid passing them to offspring.

Step #5: External Reproductive Exam

• Penis and Prepuce Evaluation: Conducted when the penis is dropped; checks for normal size, shape, and defects.

• Testes and Epididymis Examination: Evaluated post-semen collection for calmness; palpation assesses size, shape, symmetry, position, smoothness.

Step #6: Internal Reproductive Exam

• Conducted after semen collection when stallions are calmer; assesses reproductive health via palpation and examination of internal genitalia.

• Focus Areas: Inguinal rings and accessory sex glands; may be more palpable before ejaculation.

Step #7: Semen Collection and Evaluation

• Importance: Critical component of the breeding exam.

• Collection Method: Often done using a mare in heat or a breeding phantom.

  • Uses an artificial vagina filled with water and lubricant for optimal conditions.

• Evaluation Characteristics:

  • Libido assessment, semen quality, pH, volume, concentration, motility, and morphology.