Surgical Management of Penile Conditions in Bulls: Frenulum, Fibropapilloma, and Deviations

Surgical management of penile conditions in bulls refers to the diagnosis, surgical intervention, and post-operative care of anatomical or pathological abnormalities affecting the penis and prepuce of bulls that interfere with normal mating behavior or semen collection.

Injuries and other abnormalities of the penis and prepuce of bulls present major problems to the veterinarian in the semen production centre or breeding population.

Most common surgical conditions of the penis are persistent frenulum, phimosis, paraphimosis, penile fibropapilloma and penile deviation.

Persistent Frenulum

The frenulum is a collagenous band of connective tissue present at birth and attaches the glans penis to the penile section of the prepuce. The attachment should begin to break down by 4 weeks of age and separation should be complete by 8 to 11 months of age.

Persistence of the frenulum attachment beyond 11 months of age is considered pathologic When this thin band of collagenous connective tissue fails to rupture the penis can extend, but the persistent frenulum deviates the tip of the penis ventrally and may prevent intromission.

Penile Fibropapilloma

Penile Fibropapilloma in bulls is common among young bulls housed together and is caused by the bovine papilloma virus.

The virus enters the epithelium of the penis through wounds or abrasions and causes focal benign neoplastic growths of fibroblasts on the free portion of the penis and prepuce.

Homosexual riding of young bulls housed together may allow penile abrasions that allow virus entry into the epithelium. These growths are often pedunculated and located near the glans penis.

Penile Deviation

Deviation of the normal penile architecture occasionally causes copulation failure in bulls. Penile deviations are classified according to their shape and in descending order of occurrence are either spiral (corkscrew), ventral or S-shaped.

Penile deviations are caused by abnormalities of the apical ligament of the penis. Bulls affected with penile deviations are usually between 2.5 and 5 years of age and typically had one or more successful breeding seasons before copulation failure.