Castrating (Gelding) Your Horse

Why we castrate horses

Castration or “Gelding” of colts or stallions is the most common surgical procedure performed in horses. Male horses that are not intended for breeding may be castrated for a number of reasons, however the most common reason is to avoid or reduce aggressive stallion behaviour.

Castration is considered an effective means of eliminating this aggressive behaviour in the majority of cases, however it is important to note that a percentage of geldings will continue to display stallion like behaviours such as mounting and aggression toward other horses.

Other medical reasons for castrating horses include correction of inguinal hernias, trauma to the testicle or treatment/prevention of testicular cancer.

Considerations when castrating a horse:

  • Age: Castration can be performed at any age in horses, however most colts that are not intended for breeding are gelded as yearlings
  • General Health: It is always important that your horse have a good general physical examination prior to any kind of surgical procedure, as underlying disease may increase the risks associated with the procedure. If your horse has been unwell, we may recommend postponing the procedure until the horse has recovered. It is also important to check that both testicles are present in the scrotum prior to anaesthetising the horse. Sometimes only one testicle will have descended into the scrotum. These horses are known as cryptorchids or “riggs”. Castration of a cryptorchid horse is a more complicated procedure, as the abdominal cavity may need to be opened in order to retrieve and remove the un-descended testis.
  • Weather: Following castration, the incision site is left open to encourage wound drainage. Castrating in wet weather is often avoided due to increased risk of wound contamination in wet muddy conditions. Castrating during cooler weather is also preferred, as flies are at a minimum.
  • Location: Castrations are performed under a short general anaesthetic. A large open grassy area is therefore required to ensure the safety of both the horse and people is optimised.
  • Handling: Following surgery, it will be important to exercise your horse (see post-operative care) to minimize the amount of swelling around the surgical site. This is often much easier to do if the horse is at least used to lead walking. Having horses well handled prior to castration will also make management of any post-operative complications far easier to deal with.
  • Performance Horses: If your horse is currently in work, it is generally advised that they be taken out of training and fed reduced amounts of concentrates for 5-10 days prior to surgery.

Post-Operative Care

After your horse has recovered from the anaesthetic, he may be a little wobbly on his feet for the first hour or two. It is important to keep him quiet and in a clean, dry and open area for the remainder of the day. Ensure he has access to water at all times. You may offer your horse his normal feed the evening of the procedure.

Excessive Bleeding: The most common complication associated with castration is excessive bleeding (haemorrhage). All precautions will be taken to ensure the risk of bleeding is minimised, however in a small percentage of horses, excessive bleeding may still occur. If left untreated, there is a risk of serious and potentially life-threatening complications. For this reason it is important to check the wound for bleeding over the first few hours following surgery to ensure there is no excessive blood loss is occurring. Over the first few hours the wound may drip blood and this is not of concern.

Please phone us immediately if:

  • There is a continuous stream of blood coming from the incision site
  • The blood is dripping from the incision site too quickly to count
  • Blood continues to drip from the site for more than four hours after castration

Infection: All horses will be given a single injection of antibiotics at the time of castration to minimise the risk of post-operative infection. The procedure is conducted in a sterile fashion; therefore further administration of antibiotics is not warranted unless otherwise directed by your veterinarian.

Horses are also given a tetanus booster and tetanus antitoxin vaccination at the time of castration, to minimise the risk of tetanus infection in the open wound.

Please check your horses wound daily for the first 7-10 days for any evidence of infection such as a discharge or foul smell coming from the wound. If there are flies around, it is advisable to apply fly repelling spay around the wound (avoid directly spraying the wound).
Should you see any signs of infection, or should your horse become unwell (e.g. go off his food or seem depressed), please phone us immediately.

Swelling: Swelling can be a common post-operative finding. To prevent excessive swelling around the surgical site, it is important to exercise your horse for the first 5-7 days after surgery.

Ideally, horses should be walked or lunged for 10mins 2-3 times daily over this period to reduce swelling formation. This is particularly important if your horse is boxed. Cold hosing the area for 5-10mins 2-3 times daily may also assist in reducing swelling. Should swelling persist, please phone us, as this may be a sign of infection.

Eventration: This is a rare, but potentially disastrous complication of castration where part of the abdominal contents (most commonly loops of small intestine) comes out through the incision site or down into the scrotum. Eventration usually occurs within the first few hours of surgery, but may occur days following the procedure.

Should you see anything coming out through the incision site, please phone us immediately!

We would like to stress that the above complications are rare, however good monitoring by you at home will ensure that any complication should it occur, be treated rapidly. It is recommended that you do not turn geldings out with mares for 2-3 weeks following castration, to be sure there is no chance of a pregnancy. Should you have any questions or concerns, please do not hesitate to contact us!