VSR 421: Regional Veterinary Surgery (2+1)

CONDITIONS AFFECTING LARGE ANIMALS

• Most of the conditions affecting the genital system in companion animals affect large animals. Treatment of most of the conditions is also similar. However, treatment may not be attempted for conditions which have poor prognosis or diseases like tumours that have a high chance of recurrence or metastasis because of financial reasons. Valuable horses may be an exception for this.
• Conditions that are different from those in companion animals in clinical presentation and treatment are discussed.
• Hydrocele, the accumulation of fluid in the tunica vaginalis, may result from trauma to the testicle or faulty castration technique using Burdizzo castrator in bulls. Surgical treatment involves orchiectomy on the affected side by the open-covered method. In cases of bilateral involvement, bilateral orchiectomy and scrotal ablation may be performed.
• Cryptorchidism may be treated by surgical removal of the affected testicle in a standing or recumbent animal by a flank incision on the affected side. The surgery may be performed under paravertebral nerve block or standing chemical restraint with local analgesic infiltration. The use of an emasculator to severe the spermatic cord helps efficient control of haemorrhage in bulls as well as horses.
• Prepucial prolapse and prepucial fibrosis may be seen in bulls. Acute cases of prolapse of prepucial mucosa may be treated conservatively by cold application, cleaning with mild antiseptic solutions, return of the prolapsed mucosa into the prepucial sheath and application of a purse string suture around the prepucial orifice. The animal may be controlled on lateral recumbency with the fore and hind limbs tied separately under sedation and/or local analgesic administration.
• In chronic cases of prepucial prolapse, the mucosa may be sufficiently traumatized to result in infection and fibrosis during healing so as to result in sufficient stricture of the prepucial orifice to cause phimosis. The condition may be treated by surgical excision of the contracted part of the prepucial orifice (circumcision).
• Penile haematoma and contusions may occur in bulls as well as stallions and are usually associated with copulation. The extent of the haematoma and contusion also vary depending on the level of trauma. Mild cases may be left to heal on their own. Sexual stimulation should be avoided during the healing period. In extensive cases the tunica albugenia in the affected part of the penis may be incised, blood clots removed and major bleeding points arrested. This surgery may be performed in bulls under pudental nerve block and sedation and in horses under general anaesthesia in the recumbent position. The incision in the tunica albugenia may then be sutured using synthetic absorbable suture material.
• Penile deviation may be seen in bulls. This can interfere with copulation and may be of traumatic or non-traumatic origin. Traumatic lacerations and subsequent scar tissue formation can lead to penile deviation. In mild cases the deviation can be surgically corrected by treatment of the laceration and surgical release of the excessive scar tissue. In penile deviation of spontaneous non-traumatic origin spiral, ventral or “S” shaped deviation of the penis may be seen. The condition may result from a damaged or weakened apical ligament, a thick band of collagen arising from the outer layer of tunica albugenia on the dorsal aspect of the penis. The condition may be surgically treated by surgical implantation of strips of fascia lata or apical ligament into the tunica albugenia.