Total Penectomy Associated with Perineal Urethrostomy and Orchiectomy in one Sheep

Abstract

Background: The anatomical characteristics of the urinary system of male sheep increases their predisposition to traumatic and obstructive lesions due to the fibroelastic conformation of the penis and the presence of the sigmoid flexure. Total penectomy, associated with perineal urethrostomy, is indicated in cases of extensive organ involvement or irreversible necrosis. This report describes the case of a male sheep subjected to total penectomy, perineal urethrostomy, and orchiectomy after undergoing physical trauma. 

Case: An approximately 4-year-old male sheep of undetermined breed, weighing 45 kg, was treated at the Large Animal Sector of the Veterinary Hospital of the University of Passo Fundo (UPF), RS, Brazil. The animal presented with a penile lesion and dysuria for about a month, and its clinical history indicated probable physical trauma. Clinical examination revealed low body condition score, pale mucous membranes, tachycardia and tachypnea, as well as extensive laceration and necrosis of the penis and prepuce, compromising urinary function. Complementary examinations showed severe anemia, thrombocytosis, mild neutrophilia, and increased urea levels. After hematocrit stabilization and reduction of local contamination, the animal was subjected to surgery. The anesthetic protocol included xylazine, diazepam, ketamine supplemented with propofol, and maintenance with isoflurane. A lumbosacral epidural block was performed with 0.5% bupivacaine, 2% lidocaine, and morphine for complementary analgesia. During the intraoperative period, the patient experienced an episode of hypotension, which was reversed by continuous dobutamine infusion. Total penectomy was performed via an elliptical incision, with sectioning of the penis and suturing of the distal ureteral stump. Bilateral orchiectomy via scrotal ablation was then performed, followed by perineal urethrostomy via a midline incision 11 cm below the anus, forming a new urinary ostium. Postoperative care included combined antibiotic therapy with penicillin and gentamicin, multimodal analgesia with dipyrone, meloxicam, and tramadol, and daily wound dressing changes. The animal presented with suture dehiscence, and healing by secondary intention was chosen. The outcome was satisfactory, with complete wound resolution and full recovery of urinary function after 40 days. 

Discussion: The surgical management of penile conditions in sheep requires an individualized approach, considering the anatomical and physiological particularities of the species. In this case, the use of advanced anesthetic and surgical techniques in a hospital setting allowed for effective control of complications and complete patient recovery. Balanced anesthetic protocols combining sedatives, induction agents and volatile anesthetics, associated with epidural analgesia and continuous monitoring, ensured intraoperative stability. Although hypotension occurred during the procedure, it was promptly reversed by using dobutamine, underscoring the importance of hemodynamic monitoring. Total penectomy followed by perineal urethrostomy, which was necessary due to extensive necrosis and functional loss of the organ, resulted in satisfactory long-term clinical evolution. Postoperative wound dehiscence was successfully treated through healing by secondary intention and appropriate local care. This case demonstrated that, despite potential complications, complex surgical interventions can be performed safely and effectively in small ruminants, provided they are associated with careful anesthetic management and adequate postoperative monitoring. This report reinforces the applicability of advanced medical techniques in sheep and contributes to the improvement of anesthetic and surgical practices in livestock veterinary medicine.

Keywords: inhalational anesthesia, sheep, surgery, urethral orifice. 

Título: Penectomia total associada à uretrostomia perineal e orquiectomia em um ovino

Descritores: anestesia inalatória, carneiro, cirurgia, óstio uretral.