Penopexy in Bulls: Indications, Procedure, and Post-Operative Care

Penopexy in bulls is the iatrogenic creation of phimosis by surgically creating an adhesion of the penis to the ventral body wall. This procedure prevents protrusion of the penis, thus preventing normal intromission or copulation

Indications

• To produce a teaser (gommer) bull for heat detection in females
• To prevent intromission and copulation while allowing mounting behaviour
• As part of a breeding management program where sterile bulls are needed

Preparation

Penopexy is a relatively quick procedure and can typically be performed with sedation and local infiltration of 2% lignocaine.

The ventral abdomen, from the preputial orifice to the base of the scrotum, is clipped and prepared for aseptic surgery.

Surgical Procedure

A 10-cm skin incision is made midway between the preputial orifice and the scrotum, approximately 2 cm lateral to the midline.

The incision is continued through the subcutaneous tissue, followed by blunt dissection of the loose connective tissue until the penis is located. It is important to identify the urethral groove on the ventral aspect of the penis and to avoid this area during suturing of the penis to the body wall.

The penis is exteriorized through the incision, and the dorsal surface is cleared of elastic tissue for a length of 10 cm immediately caudal to the preputial reflection.

The fibrous tunica albuginea is exposed and sharply scarified to ensure strong adhesion formation. A corresponding area of the linea alba also is cleared of loose connective tissue and scarified.

Carefully dissect the subcutaneous tissues until the penis is identified and exteriorized.

Once the penis is exteriorized through the incision, identify the caudal reflection of the penis (fornix) and dissect the subcutaneous tissues on the dorsal aspect of the penis until the tunica albuginea is exposed for approximately 10 cm caudal to the fornix.

After preparation of both sites, the urethral groove is identified on the ventral aspect of the penis.

Beginning 6-8 cm caudal to the fornix of the penis, pre-place four to six simple interrupted sutures approximately 2 cm apart using a heavy non-absorbable suture.

The suture is placed through the dorsal third of the penis using care to not enter the urethra and such that the glans penis is approximately 12 cm caudal to the preputial orifice. The suture is then placed through a corresponding area of the linea alba.

Once all the sutures are pre-placed, return the penis to the normal anatomical position and ensure it is not protruding from the preputial orifice prior to securing all the sutures.

Close the subcutaneous tissue with absorbable sutures and the skin with Size 3 non- absorbable suture in a Ford interlocking pattern.

The skin sutures are removed in 10 days, and the bull may be used by 3 to 4 weeks after surgery.

A variation of this technique involves fixation of the penis to the heavy subcutaneous tissues in the perineal region.

The site of fixation is 15 to 20 cm proximal to the attachment of the retractor penis muscles.

This is a relatively quick and simple procedure to perform. Failure of the procedure or urethral penetration may occur if the sutures are not placed properly.

A vasectomy or epididymectomy is usually performed in conjunction with a penopexy to ensure sterility of the bull in case of procedure failure.

Post Operative Care

• Monitoring the surgical site daily for signs of infection, swelling, or discharge
• Antibiotics and anti-inflammatory drugs
• Skin sutures approximately 10 days post-surgery
• Limit strenuous activity for 3 to 4 weeks until full healing occurs
• Urethral damage or urinary obstruction monitoring
• Re-evaluation of the animal before use as a teaser bull to ensure successful adhesion and healing