XLVets Equine's Dr. Aoife Byrne DrMedVet MRCVS tells us all about treating a horse called Jimmy, but not all's as it seems...
When is a gelding not a gelding? When it’s cryptorchid! This was the problem presented to me by a client last week.
Her male horse Jimmy was displaying stallion-like behaviour and he was old enough and mature enough to have two testicles present in his scrotal sack. After sedating him and having a good feel, I couldn't palpate anything resembling a testicle, let alone two, and I couldn't feel a castration scar either.
The owner didn't know the horse’s history before she bought him so to be sure he wasn’t just a ‘riggy’ gelding, I decided to take a blood sample to check for a specific hormone associated with testicular tissue.
This test came back positive, confirming the diagnosis of what's commonly known as a ‘rig’.
This is a condition when one or both testicles have been retained in the inguinal canal or abdominal cavity.
It happens when the foetal testicles do not descend through the inguinal canal and into the scrotum during the final weeks of foetal development. One or both testicles can be retained anywhere along its descent.
Cryptorchids are classified as ‘abdominal’ or ‘inguinal’, depending on the location of the retained testicle. Inguinal retention is by far the more common of the two.
Jimmy’s case was a rare one because he had what's termed a complete abdominal retention. This meant both pairs of testicle and epididymus were retained within the abdomen.
I explained the situation to the owner and highly recommended that Jimmy was castrated. This would put an end to him behaving like a stallion and also prevent the retained testicles potentially becoming cancerous in the future.
Jimmy underwent a general anaesthetic to surgically remove the testicles from his abdomen. It was quite a tricky operation for our surgeon as the testicles were fairly mobile and mixed up with coils of intestine making them very tricky to locate at surgery!
When they were finally found, they were abnormal – one was quite small and the other incredibly large like a fluid filled cyst. This probably occurred due to the higher abdominal temperature compared to that of the scrotal sack.
He recovered uneventfully from his anaesthetic and went home to his owner the next day.
A few weeks on from surgery and with the testosterone waning in his system, Jimmy has settled quite happily into his new life as a gelding!