A technique for transrectal ultrasonography of stallions during ejaculation

A technique was developed in which the accessory sex glands of stallions were visualized with transrectal ultrasonography during ejaculation. The technique was judged to be effective, since 10 of 11 stallions were trained to tolerate transrectal ultrasonography during ejaculation; they ejaculated during 195 of 200 attempts, and acceptable visualization of their accessory sex glands and excurrent ducts occurred during 97 of 195 ejaculations. Sixty-five percent (89 136 ) of the recordings were successful for stallions that weighed more than 300 kg, whereas 14% (8 59 ) of the recordings were successful for stallions weighing less than 300 kg. The 98 unsuccessful attempts were caused by inaccurate transducer placement due to the small size of the pelvic canal(33 98 ), excessive transducer movement due to stallion movement (32 98 ), indistinct ultrasound images (28 98 ) and human error (5 98 ). The technique was judged to be safe, since no stallions or personnel sustained serious injuries during 200 data collection attempts.