Do Horses Need to Get Spayed/Neutered?

horse and its foal

Many horse owners wonder if they should spay or neuter their horses. Unlike with cats and dogs, fixing horses is not an automatic choice. Spaying and neutering horses has pros and cons depending on age, sex, breed, and use.

Why Fix Dogs and Cats but Not Always Horses?

To control the number of cats and dogs, vets often spay or neuter them. But horses are not at risk of contributing to overpopulation. And as large, domesticated livestock, their circumstances differ from house pets. So, the decision requires more thought for equine owners.

What Are the Potential Benefits?

Some advantages can make gelding male horses or spaying mares a good choice:

  • Gelding eliminates stallion-like behaviors in males, like aggression and sexual urges. This makes geldings calmer and safer to handle

  • Spaying prevents the moodiness and discomfort mares experience during heat cycles. It also prevents the risk of accidentally getting pregnant

  • Sterilization prevents hormonally-driven behaviors that can disrupt performance

  • It prevents reproduction in horses unfit for breeding due to genetics or conformation

  • It helps with horse population control

What Are the Drawbacks?

There are also some drawbacks to consider:

  • Hormones can influence performance in challenging sports like racing

  • Spaying removes reproductive organs versus just suppressing hormones

  • Training can often manage undesirable stallion-like behaviors even without gelding

Factors to Consider in the Decision

Whether gelding or spaying makes sense depends on several factors:

Age of the Horse

It is best to castrate male horses before they are 18 months old. This reduces aggressive behavior similar to stallions. When it comes to female horses, it’s best to wait until a filly is at least two years old before considering spaying.

Breed and Intended Use

Certain breeds and disciplines may benefit more from sterilization. The procedure's impacts on strength and stamina need consideration for high-performance horses. But for casual riding or companion horses, behavioral benefits often outweigh performance concerns.

Housing Situation

Gelding is best when housing male horses together. The procedure reduces the risk of injury from sparring and hierarchy disputes. For female horses housed with geldings, spaying also minimizes disruptive heat cycles.

Trainer Experience

A skilled trainer can handle stallion-like behaviors in a male horse without surgery. But for safety reasons, gelding is best if the horse will have many handlers.


It costs a lot to geld and spay horses, but it stops breeding problems and expenses. For facilities with limited space, preventing the birth of more horses may justify the investment.

Can Sterilization Be Temporary?

Alternatives to permanently sterilizing competition horses can provide hormonal benefits. These include:

Suprelorin Implants

These implants can temporarily lower testosterone or estrogen production, causing reversible chemical castration. Effects wear off over 1-2 years once implanted.

Injection Steroids

Administering steroids like testosterone cypionate can temporarily limit heat in mares. Yet, long-term use has health risks, including liver damage.

Pill Forms

There are risks when using oral steroids and hormones for a long time, but they can be used temporarily. They require careful veterinary monitoring. Sterilization is a very reliable method. It permanently stops horses from misbehaving and reproducing. Yet, some alternatives provide temporary options in select cases.


Spaying and neutering can make horses less aggressive and reduce heat cycles, but it is not always the best option. Before deciding, consider how surgery might affect your horse's performance and the risks. Consider all factors before determining if your horse could benefit from the procedure.

For more about horse sterilization, visit Chaparral Veterinary Medical Center at our office in Cave Creek, Arizona. Call 480-595-8600 to book an appointment today.