Spaying and Neutering Horses: Mare Spaying and Gelding Basics

Gelding is the surgical removal of both testicles. In many horses, your vet can perform castration as a standing procedure with sedation and local anesthesia or under short general anesthesia. Technique matters. Some horses are good candidates for routine field castration, while older stallions, horses with large inguinal rings, or horses with suspected retained testicles may need a more controlled hospital setting.

After routine castration, some drainage and swelling can be expected for a few days. Light controlled exercise is often part of aftercare because movement helps drainage. Your vet may also recommend tetanus protection, anti-inflammatory medication, and careful daily monitoring for bleeding, fever, severe swelling, depression, or tissue protruding from the incision.

In mares, people often say spay, but the procedure is usually an ovariectomy rather than the dog-style spay that removes the uterus and ovaries. A mare may have one ovary removed if there is a suspected granulosa-theca cell tumor or another ovarian abnormality, or both ovaries removed if the goal is to stop cycling permanently.

Mare ovariectomy may be performed standing through the flank or laparoscopically in selected cases, or under general anesthesia in a hospital. Compared with gelding, it is less common, more technically demanding, and usually more costly. Recovery time and risk depend on the surgical approach, the size of the ovary, whether the mare is pregnant, and whether there are complications such as bleeding.

Common reasons to geld a horse include preventing breeding, reducing stallion management challenges, and making herd or training situations safer and easier. Many horses are gelded when young, but older stallions can also be castrated. Older age can increase the chance of complications and may mean stallion-like behavior persists to some degree after surgery.

Common reasons for mare ovariectomy include a suspected granulosa-theca cell tumor, a persistently enlarged or abnormal ovary, or hormone-related behavior that your vet believes is linked to ovarian disease. Surgery may also be discussed when a mare has pain or reproductive tract findings that make ovarian removal the most practical option.

No equine reproductive surgery is risk-free. With gelding, important complications include persistent bleeding, infection, excessive swelling, funiculitis, and evisceration. Merck notes that tissue protruding from the incision or ongoing bleeding after castration is an emergency, and risk of evisceration is higher in adult stallions and some breeds with larger inguinal rings.

With mare ovariectomy, concerns include bleeding into the abdomen, incisional complications, pain, and anesthesia or sedation risk. Referral surgery may lower some risks by allowing better visualization, specialized instruments, and closer monitoring. Your vet can explain which complications are most relevant for your horse rather than relying on general averages.

For a routine field gelding, many U.S. pet parents can expect a cost range of about $300-$900, depending on region, sedation, farm call, tetanus status, and whether pre-op bloodwork is done. A hospital-based routine castration often runs $800-$2,000+. If the horse is a cryptorchid or has a retained testicle, the cost range commonly increases to $2,500-$6,000+ because advanced imaging, laparoscopy, or abdominal surgery may be needed.

For a mare ovariectomy, the cost range is usually much higher. A straightforward unilateral ovariectomy at a referral center may fall around $2,500-$5,500, while laparoscopic, bilateral, large-ovary, or more complex hospital cases can reach $5,000-$10,000+. Extra charges may include ultrasound, hormone testing, pathology, hospitalization, and management of complications. Ask your vet for a written estimate with best-case and higher-end scenarios.

Most horses recover well when the case selection and aftercare are appropriate. After gelding, your vet may recommend stall rest for a short period followed by hand-walking or turnout, depending on the technique used. After mare ovariectomy, activity restriction is often longer, especially after abdominal surgery. Follow the exact discharge plan your vet gives you.

Call your vet promptly if your horse has steady dripping or streaming blood, fever, worsening pain, foul-smelling discharge, severe swelling, loss of appetite, colic signs, trouble walking, or any tissue protruding from a castration incision. Those are not watch-and-wait findings. Early treatment can make a major difference in outcome.