Diagnostic ultrasonography for evaluation of cryptorchidism in horses.

The location and size of 11 retained testes were accurately determined ultrasonographically. There was 100% correlation between the location of the testis determined by ultrasound vs that determined by surgery. Testicular size determined presurgically in all cases closely approximated the actual size obtained by gross measurement of the excised testis. The cryptorchid testicular echotexture was less dense than that of the normal descended testicles, but was easily identified. Ultrasonographic evaluations were completed by use of an ultrasound base unit with attached 5-MHz transrectal transducer. Rectal scans were started at the pelvic brim and continued in a to-and-fro pattern between the midline and the lateral abdominal wall. When the testis was located, the image was froze to allow measurement. All testicular locations were ascertained ultrasonographically either by rectal or external inguinal scans.