Although uncommon, reproductive emergencies will occur in the breeding stallion and when they do, prompt attention and action must be instituted. Trauma to the external genitalia is always a possibility under natural mating situations whether the stallion is used in a hand mating situation or field breeding. Some mares are presented to the stallion when not in true standing estrus or even if in estrus they can react violently to being mounted by the stallion In addition, stallions can also be injured when semen is collected by the use of an artificial vagina in an inappropriate manor when mounting a phantom or jump mare.

The majority of injuries or accidents I see are the result of direct trauma (kick from a mare) or to a lesser extent from a mare’s tail hairs stretched across the vulva lips. Occasionally, trauma to the penis can occur to bending of the penis during semen collection with an artificial vagina or on the phantom itself. When these types of injuries occur, disruption in the breeding season occurs, and we should try to resolve the insult as quickly as possible.

Inflammation of the penis (balanitis) is probably the most common disease of the penis. If the prepuce is included, then balanoposthitis is more descriptive. Swelling and redness are the most obvious signs.

Equine herpes 3 is a viral cause of balanitis (Pox, coital exanthema). The disease is characterized by small blister-like vesicles forming on the shaft of the penis and occasionally on the prepuce. Serum is exuded and in three to seven days small crusts will form on the lesions. When these crusts fall off, small ulcer-like lesions remain, which soon heal. Since the virus is spread by coitus (intercourse), sexual rest is the treatment of choice. In addition, a mild antibiotic ointment might be applied to the lesions to prevent or minimize secondary bacterial infections. This disease is highly contagious and the stallion should be out of service until healing is complete. This usually takes one to four weeks