Orchitis

Description

When the testes of a horse become swollen, painful, and warm, orchitis may be the cause. Orchitis can be bacterial, viral, parasitic, or auto-immune in origin and can develop either uni- or bilaterally. Examination of semen, if it can be obtained, will reflect that spermatozoal motility is decreased and abnormalities are increased. If not treated properly, a testicular abscess may develop.

Epididymitis, the inflammation of the coiled tubles on top of the testicle, may be present. Sexually-transmitted bacterial infections are the most common cause. The infection starts in the urethra and works its way to the testicle.

Symptoms

• Hard, swollen mass in the scrotum
• Pain
• Elevated testicular temperature
• Decrease in semen quality, motility, and increase in abnormal forms
• A hopping gait because of discomfort

Causes

Caused by Strep zooepidemicus, Klebsiella, Salmonella, Influenza virus, viral arteritis, and equine infectious anemia, orchitis may result from ascending infection or hematogenous spread of a systemic infection.

Orchitis may also be caused by testicular cord torsion resulting in interference with circulation and infarction of the testes.

In addition, trauma to the testes and inflammation of the testicular artery due to migrating strongyle larvae may result in orchitis.

The most common causes of orchitis are sexually-transmitted bacterial infections, including Streptococcus zooepidemicus, an infection that starts in the urethra and works its way to the testicle. Local invasion of the testes can be secondary to peritonitis or a penetrating wound. .

Although not frequent, viral orchitis may be the cause of testicular degeneration as a result of equine influenza, viral arteritis, and equine infectious anemia.

Parasitic orchitis is associated with the migration of Strongylus edentatus causing testicular irritation and adhesions.

Auto-immune orchitis may result from testicular trauma and damage to the blood-testis barrier. .

Prevention

Good horse management to prevent infection or injury to the horse's testicles is important. Also, keeping horses healthy with an appropriate diet, plenty of exercise, and prompt attention to the earliest signs of disease will be helpful in preventing diseases that affect the testicles.

Keeping stallions from associating or interacting with other horses that have sexually-transmitted bacterial infections will help reduce the number of occurrences. Careful screening is necessary.

Proper sanitation practices and disinfecting of premises on a regular basis helps in many cases.

Treatment

Ice packs and cold water hydrotherapy should be applied to the scrotum to reduce pain and swelling. An external support to elevate the testicles will relieve pressure.

High levels of systemic antibiotics for several days may be recommended by a veterinarian. Ultrasound of the testicle can be used to distinguish between infection and trauma and to determine if the epidiymis is involved.