Perineal Hernia in Dogs

Background: Perineal hernia is a serious disease characterized by weakening or atrophy and separation of the muscles and fasciae of the perineal musculature, followed by the caudal displacement of pelvic and abdominal organs to the perineum region. Treatment is invariably surgical and several approaches have been proposed, but complication and recurrence rates remain high. This study aimed to evaluate 120 cases of perineal hernia treated at the Veterinary Hospital of Uberaba (HVU) from 2005 to 2020, addressing the clinical and surgical aspects and the postoperative period, seeking to identify the most relevant factors to improve care and treatment of future patients affected by this disease.Materials, Methods & Results: The medical records of dogs with a definitive diagnosis of perineal hernia were collected. The prevalence of perineal hernia was calculated. Data were obtained regarding sex, being castrated or not, age, body mass, race, clinical signs, affected side, possibility of hernia reduction, treatments used, associated pathologies. Of the 120 cases, only 69 underwent surgery at the HVU and from these cases data were obtained regarding hernia content, surgical techniques, surgical wires used, recurrences and postoperative complications. Fisher's exact test was applied to assess the influence of the type of surgical treatment and surgical thread on the occurrence of complications and recurrences. Perineal hernia was the second most frequently observed hernia. Mixed breed, male, non-neutered and geriatric dogs were the most affected. The most frequently observed clinical signs were related to the digestive and urinary tract, consistent with the most commonly found hernia contents (bladder, prostate and rectum). The simple herniorrhaphy technique was the most used and showed a high number of complications. The second most used technique was the elevation of the internal shutter, which proved to be more efficient than the simple technique. Regardless of the technique used, the association of two or more techniques proved to be more efficient to reduce major complications. The use of the vaginal tunic stood out because it proved to be efficient in the treatment of perineal hernias regardless of whether it is associated with simple herniorrhaphy or obturator elevation. The surgical fixations of abdominal organs (Bladder, Ducto deferente and Colon) proved to be effective, since there were no recurrences or major complications associated with their use and the most used threads for herniorrhaphy were polyamide and catgut. Low recurrence rates were found in patients who received synthetic yarns. The most frequent complications were suture dehiscence and serous secretion.Discussion: Perineal hernia is a very important alteration due to difficulties in treatment, high rates of complications and recurrence, in addition to the large number of affected dogs. Several surgical techniques have already been proposed for the treatment of perineal hernia in dogs and are based on the reconstruction of the perineal musculature through sutures, muscle flaps, biological membranes, synthetic mesh and the reduction of pressure on the perineum through the surgical fixation of organs abdominals such as colon, vas deferens and bladder (in the musculature of the abdominal wall). It is concluded that the perineal hernia affects mainly male, non-neutered and geriatric dogs, being rare in females. Regardless of the techniques used, the association of two or more techniques is more efficient to reduce the rate of recurrences and complications. The autogenous vaginal tunic is a good option for muscle strengthening in perineal herniorraphies. The use of synthetic surgical wires leads to better results in the treatment of perineal hernia when compared to biological wires.