Preoperative Ultrasonography for Retained Testes

Canine and feline testes usually descend into the scrotum by 10 days of age. If testes have not descended by 8 weeks, cryptorchidism is likely. Although considered congenital, cryptorchidism’s exact mode of inheritance is unknown. Incidence is higher in dogs than in cats, and complications include sterility and testicular torsion. Risk for neoplastic transformation is higher in undescended testicles of dogs. Diagnosis and localization of undescended testicles can be difficult; in one evaluation, palpation to locate the retained testis was successful 48% of the time.

This study evaluated ultrasound use to locate undescended testes in 30 dogs and 4 cats; final testicular location was confirmed surgically. Forty-three testes were retained (26 right, 17 left), 18 were in the normal scrotal position, and 7 were absent from previous surgical removal. Twenty-eight retained testes were in the abdomen and 14 in the inguinal region. There was a 100% positive predictive value for the 42 abdominal and inguinal testes seen on ultrasound; all were found during surgery. One abdominal-retained testis was not identified via ultrasound. Preoperative ultrasound can help facilitate location of retained testes before surgical exploration or laparoscopy.

CommentaryThis study could be useful for those with intermediate to advanced ultrasonography skills. A small fat accumulation palpated in the inguinal region may be mistaken for a retained testicle and result in unnecessary surgical time. On sonographs, testicles can be distinguished from fat and intraabdominal testes and should not be confused with mesenteric lymph nodes. With experience, testes can be readily differentiated from fat and lymph nodes. Private practitioners wishing to increase proficiency in identification of retained testes are encouraged to receive appropriate training and routinely image normal testicles in the scrotum of patients presenting for neutering. Ultrasonography for preoperative planning can reduce surgical time and perioperative morbidity, thereby improving patient care, increasing client satisfaction, and reducing practitioner stress.— Ajay Sharma, BVSc, MVSc, DVM, DACVR

SourceUse of ultrasound to locate retained testes in dogs and cats. Felumlee AE, Reichle JK, Hecht S, et al. VET RADIOL ULTRASOUND 53:581-585, 2012.