You may have come across the terms 'cryptorchid' or 'rig' refering to male horses.

These terms mean that one of the horse's testicles has not decended into the scrotum, This can cause serious complications at castration, and the retained testicle may become cancerous, or twist on itself and seriously endanger the life of the horse.

If a rig is castrated without retrieving the missing testicle, he may still be fertile and act like a stallion, despite the physical appearance of a gelding. He may also be fertile.

Retained testicles are very likely to develop Sertoli cell tumours, which can get very large and have a feminising effect on the horse. They may also twist on their artery, potentially causing a fatal colic.

A retained testicle may be located just at the entrance to the scrotum, and may descend by the time the horse is 3, at which point normal castration can be performed. Alternatively, it could be located anywhere between the scrotum and the kidney on the same side. Cryptorchids are, for this reason, much more difficult to castrate than normal horses.

There is some evidence that cryptorchidism is genetic, so itis highly advised to properly castrate these horses.

If you think your horse is a cryptorchid, get your Vet to check. Most horses strongly resent being inspected in the scrotal area, so should only be done by a proffessional with a bag of equine sedatives.

Tell me if I'm wrong here for what I understand in what you have said is that owners could do the castration themselves. I assume that proper castration must be done only by vets so that this kind of illness (cryptorchid) would be immediately taken cared of.

It is best to have a vet out to castrate a horse, especially if they are older.

However, some owners don't want to deal with the expense of treating a cryptorchid, so will remove one testicle themselves and declare it a gelding, which is irresponsible and bad for the horse.

Owners of foals can examine the foals at birth though, and do a little counting. :)

When you talk about horses, there is no cheap thing. For if you go for cheap equipments or services, your horse will suffer. If you really want to have a horse, you must have enough money for whatever expenses your horse needs. And treating diseases of horses must not be taken for granted. Better have the vet do what he studied to do for the vet knows what is best for our horses.