Also see Breeding Soundness Examination of the Male. The breeding soundness examination should begin with a thorough history, including information regarding libido, mating ability, fertility, prior illness or injury, and any medications administered. A general physical examination should be performed, noting lameness (particularly of the back and hindlimbs) and heritable conditions that may affect breeding ability or desirability as a sire. The penis and prepuce should be free of lesions. The testes and epididymides should be evaluated for size, shape, and consistency. The testes should be freely movable within the scrotum and have a total scrotal width >8 cm. The internal genitalia, inguinal rings, and aorta and iliac vessels are evaluated by palpation and ultrasonography per rectum. For semen collection and evaluation techniques, see Breeding Soundness Examination of the Male.

If consistent heavy growth of potential pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae, or Streptococcus zooepidemicus is seen on aerobic culture of swabs of the penile fossa or urethra and there is a history of repeated infection in mares bred, it may be necessary to breed by artificial insemination using semen extender containing an appropriate antibiotic. If natural service is required, semen extender containing an antibiotic may be infused into the mare's uterus before servicing. If Taylorella equigenitalis is present, the stallion should not be used for breeding (see Metritis in Large Animals: Contagious Equine Metritis). The isolation of T equigenitalis requires special culture conditions; the organism will not grow in routine aerobic cultures. Stallions with lesions of coital exanthema (see Equine Coital Exanthema) should not be used for breeding until skin ulcers are completely healed.

Last full review/revision July 2011 by Patricia L. Sertich, MS, VMD, DACT