We offer castration or gelding services at MBM Vets

Castration, also known as gelding or cutting, is a surgical procedure involving the removal of testicles from a colt or stallion. For most horse owners, castration offers a means to eliminate or reduce unwanted stallion behaviour such as the mounting of mares, fighting or attacking other geldings and foals, and aggressiveness towards humans.

  • Most colts can be castrated from 5 months old as long as both testicles have descended. This usually occurs by around 8 to 10 months of age. If they have not descended at this time, they are unlikely to do so, and may require a more involved surgical procedure. We advise having a vet ensure both testicles are present prior to setting a castration date.


    There is no age limit as such with older stallions, however the risk of complications increases with age.


    We recommend castrating most animals in the spring or autumn to avoid complications associated with flies and mud.

  • Your colt may be a cryptorchid or ‘rig’. Please see our webpage discussing this here.

  • Stallions older than 3 years old should be castrated at the clinic due to the increased risk of operative complications unless otherwise agreed upon with one of our vets. Ideally castrations should be carried out at the clinic but can be performed at home, as long as the facilities are suitable.

  • 1. Safe and sound loose box of adequate size (at least 3m x 3m approximately), ideally with no protrusions from the walls such as automatic waterers, etc.


    2. Deep, clean straw bed to provide padding during anaesthetic induction. Shavings and sawdust are not suitable.


    3. A confident handler present who may be asked to assist if required.


    4. A consent form will need to be signed before the procedure can go ahead.

  • At MBM, all geldings are performed under general anaesthetic. An intravenous catheter will be placed in the neck to allow for anaesthetic top-ups. Tetanus anti-toxin will be administered. Sedation will be administered followed by the anaesthetic, which will result in the horse gently collapsing to the ground. A cover is placed over the eyes and the upward facing hindleg is anchored forward to the horse’s neck to allow for scrotal access. An intramuscular injection of long-acting antibiotic may be given at this time. One or two surgical incisions are made over the scrotum to exteriorise the testicles. Ligatures are placed as close to the body wall as possible around the blood vessels and network of tubes running from the testicle into the abdomen. Emasculators are applied just below these ligatures to crush and cut the underlying tissue, allowing for testicle removal. The incision sites are either left open to allow for drainage or may be closed with glue. A potent anti-inflammatory/painkiller will be given via the catheter.

  • Due to their prey nature, many horses will enter ‘flight’ mode even if the anaesthetic hasn’t completely worn off and try to get up too soon, which can result in injury to themselves. Our vets will try to keep the horse down in a quiet, calm manner for as long as possible to ensure they are mostly awake before trying to get up. The sedation should wear off within an hour. Food should be withheld until they are fully awake and able to eat. A gelding aftercare sheet will be supplied to you with post-operative advice and problems to look out for.

  • At MBM, we recommend a period of 48 hours box rest coupled with 15 minutes hand-walking twice daily. After this, turnout in a small paddock is recommended for 2-3 weeks. Movement will help to reduce swelling at the surgical sites. Cold hosing may be recommended if there is a large degree of swelling. Oral anti-inflammatories and/or antibiotics may be prescribed.


    It is important to remember that your horse can remain fertile for up to 6 weeks post-op and must be kept separately from mares during this time.

  • Although regarded as a routine procedure, castration is an invasive surgery and complications can occur. Anaesthesia always carries a risk in equines and, although this is relatively low in young fit animals, the possibility of complications is still present and should be appreciated.


    One of the most common post-op complications is bleeding. A small drip of blood from the incision site(s) can be normal 24-48 hours post-operatively. If you are unable to count the drops of blood as they fall, or notice a continuous stream of blood, please contact the practice immediately.


    A small amount of scrotal/sheath swelling is considered normal; however, this should improve with movement and your horse should be well in himself. A dramatically swollen scrotum/sheath (often coupled with a fever) can be indicative of a post-operative infection which often occurs due to environmental contamination. You may notice that your horse is duller than normal and off his food. In some cases, there may be evidence of purulent, malodourous discharge from the surgical sites. This will require veterinary attention to assess if a course of antibiotics is warranted or if the incisions need to be re-opened to establish drainage.


    Sometimes, tissue material may protrude from the surgical sites. This may be a bit of the vaginal tunic (the sac which the testicle previously sat in) which can be trimmed away. However, in rare cases, pieces of intestine can prolapse which is a serious emergency and requires veterinary intervention immediately. We advise contacting the practice immediately if you notice any protruding tissue.

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