Evaluation of semitendinosus muscle transposition for treatment of perineal hernias in 33 small-breed dogs.

Little is known about the perioperative complications and treatment outcomes of repairing perineal hernias using semitendinosus muscle transposition (SMT) in small-breed dogs. The objective of this study was to retrospectively evaluate the complications and prognosis of perineal hernia repair using SMT in 33 small, male dogs (weighing < 15 kg). Before the study began, the medical records of all small-breed dogs that underwent SMT from March 2013 to June 2022 at the Veterinary Medical Center, University of Tokyo were analyzed, and telephone interviews were conducted with their owners or referring physicians. Short-term complications were observed in 42.4% of the patients. Lameness was the most common complication, although all cases were resolved within a few days. The recurrence rate during the study period (median: 265 d) was 9.1%. The results of this study showed that transposition of the semitendinosus muscle is more invasive than other surgical procedures for perineal hernias. It is, however, an effective alternative when repair with internal obturator muscle transposition alone is expected to be difficult, such as severe atrophy of the internal obturator muscle or herniation in the ventral direction, and in cases with a history of surgery by transposition of the internal obturator muscle.