Castration: A Crucial Part of Responsible Ownership

Castration: A Crucial Part of Responsible Ownership

The castration procedure is routine and simple and can be performed at a clinic or in the field.

Photo: Caitlin Freeny, DVM

It’s that time of year for many male horses—castrating season. Castration is the surgical procedure veterinarians perform to turn a stud horse or colt into a gelding by removing his testicles. 

Being a responsible horse owner involves deciding if and when castration is appropriate. Castration is necessary if a horse is not of significant breeding value. If time and performances are needed to determine potential breeding value, an owner must manage and train the colt to prevent behavioral problems. 

Testosterone is constantly present in the stallion, and this leads to aggressive behavior, making some stallions dangerous to be around. So, timing is important for castration; it should be done after the effects of testosterone have helped the horse reach skeletal maturation, but before they’ve started causing aggression. Once aggressive behavior develops, the American Association of Equine Practitioners reports there is a 65% chance it becomes habit and will not cease after castration. 

Unfortunately, there is a quickly growing population of so-called unwanted horses, and now more than ever responsible horse ownership includes the timely castration of any male horse before he creates undesirable offspring (because of both conformational traits and behavior!). 

A candidate for gelding should be examined by a veterinarian about two weeks prior to gelding to ensure he is healthy. He should also be current on deworming and vaccinations. In many areas, fall and early winter are ideal castrating times; the flies and heat of spring and summer can interfere with healing. Veterinarians can geld stallions any time of year if necessary, and a discussion with your veterinarian will help you determine when is appropriate for your horse. 

The castration procedure itself is routine and simple, and the veterinarian can perform it at an equine hospital as well as in a mobile setting. The horse will receive a tetanus toxoid booster at the time of the procedure. The practitioner can use sedation and local anesthesia on the standing horse or general anesthesia while the horse lies on the ground or surgery table. Whether the procedure is performed standing or lying down is a decision your veterinarian will make based on the -situation. 

A routine castration can only be performed if both the horse’s testicles have descended. Horses that have retained one or both testicles are cryptorchids, also known as ridglings or high-flankers. A cryptorchid castration is less routine and requires a more invasive procedure to retrieve both testicles. Veterinarians can perform cryptorchid surgeries through exploratory abdominal surgery or laparoscopy. All cryptorchids should be castrated, as the defect is heritable and considered an undesirable trait by many breed standards. Cryptorchids may be sterile or their testicles might produce decreased amounts of sperm, but they still produce testosterone. Don’t be fooled: If you have a male horse that doesn’t drop two testicles, he still needs to be gelded! 

Post-castration, appropriate aftercare is crucial for proper healing. Your veterinarian might administer both antibiotics and non-steroidal anti-inflammatories, and he or she will give you specific instructions unique to your horse’s needs. 

Aftercare instructions usually include providing shelter, exercise, and a clean environment, and information on how to recognize complications, though they are rare. Swelling is the most common complication and typically resolves with exercise. Your veterinarian will tell you what to consider an emergency. For the first 12-24 hours after castration, keep the gelding in a paddock or stall. If stalled, he should have clean bedding. Keeping your horse in an enclosed area will allow you to observe him closely for complications. Exercise helps promote healing and blood flow beginning 24 hours after surgery. The gelding must trot or walk for 15 to 20 minutes twice daily for two weeks to prevent fluid pocketing in the scrotum and tissue swelling. 

Testosterone levels and aggressive behavior will take several weeks to dissipate. Keep gelded horses separate from mares for two to four weeks after surgery, as there still may be semen present in accessory sex glands.

One sure way that horse owners can help fight the growing population of unwanted horses is by gelding any horse that is not of significant breeding value and by gelding before aggressive behaviors arise. Be knowledgeable about the castration process and educate fellow horse owners about its necessity. 

About the Author

Caitlin Freeny, DVM

Caitlin Freeny, DVM, is an ambulatory equine veterinarian based in Flower Mound, Texas. As a general practitioner, she focuses on keeping horses healthy through preventative medicine and chiropractic care.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More