Castration Is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testes

Castrating at an early age makes sense because young colts are easy to handle, the testicles are smaller and the incision can be sutured closed. That means less swelling and a resultantly good cosmetic appearance. Horses castrated in their weanling year do not develop some of the musculature and neck and facial features associated with stallions. These early geldings keep finer features, thinner necks and lighter muscle mass, though they can grow taller than they might if left entire.

Many castrations are performed on colts between one and two years old, and due to the larger size of the testicles, the incisions must remain open. Since open incisions are more susceptible to fly irritation, spring and fall are the preferred times of the year, before or after fly season. (In general, avoid extremes in weather because they slow healing and can add to post-surgical complications.)

Veterinarians use two castration techniques. "Up" castrations are done with the tranquilized horse standing. Additional anesthetic is injected into the nerves of the testicular cords. The surgeon stands near the horse, leans over and removes the testicle using a special piece of equipment that cuts the cord, crimps and seals the blood vessel and removes the testicle.

Horses are given a short-acting general anesthetic for "down" castrations. The veterinarian usually ties up one of the horse's hind legs and performs the surgery while kneeling over the prone animal.

Each approach has its advantages and disadvantages and owners should discuss the choices with their veterinarian. Neither technique is universally better than the other.

A new technique using a clamp-like devise applied to the testicular cord is being tested at the University of Georgia Veterinary School. It is attached to a regular power drill. The drill spins the clamp, which twists the cord until it breaks. This technique effectively seals off the blood vessels. There seems to be less swelling than in the standard procedures, with no increase in complications.

Horses are generally born with their testicles in the scrotal sac or they descend through a small hole or "ring" in the belly and are in the sac shortly after birth. Occasionally, one or both testicles will remain in the abdomen or only partially emerge through the ring. These testicles may drop down at a later date; some never descend.

A horse with undescended testicles is called a cryptorchid, and general anesthesia and surgical exploration of the abdomen is necessary to castrate successfully. New laproscopic techniques utilize a long, thin camera and long, thin instruments inserted into small incisions in the belly wall to perform the removal of these retained testicles. This saves the horse from the stress of opening the abdomen - and the resultant longer recovery.