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!

Worming your Horse

There are a number of different species of parasitic worms that infect horses. These include: ascarids (roundworms); large and small strongyles; tapeworms; pinworms; thread worms; stomach bots and lungworms.

Worms irritate the gut lining and lead poor digestion and absorption of feed. Most worms live in the intestinal tract and release eggs that are passed out into the paddock in manure. Eggs will then hatch and larvae develop in the manure and pasture.

Horses grazing grass that has been contaminated with infected manure will ingest the larvae, which then develop into mature adult worms and perpetuate the infection.

How can I tell if my horse has worms?

Horses that have a high worm burden may develop some or all of the following signs:

  • Poor coat condition
  • Poor weight gain or weight loss
  • Diarrhoea
  • Colic
  • Peritonitis

Tests can be run on faecal samples to assess the current worm burden of your horse and identify any resistance to worming products that may be occurring. Regular worming of all horses on your property with an appropriate type and amount of worming product in conjunction with good pasture management, will effectively control worm burdens in your horses.

Products Available from Bega & Cobargo Veterinary Hospitals

The following products are safe to use in all adult horses, mares at all stages of gestation and foals over the age of 6 weeks.

  • Equimax Oral Paste for Horses (Abamectin + Praziquantel)
  • Promectin Plus Allwormer Paste for Horses (Abamectin + Praziquantel)
  • Ammo Allwormer paste for horses (Abamectin + Morantel Tartrate)
  • Prazivec Oral Paste for Horses (Praziquantel + Ivermectin)
  • Equest Plus Tape Long Acting Horse Wormer and Boticide Gel (Praziquantel + Moxidectin)
  • Equiban Granules (Morantel Tartrate)

Basic Steps to good worm control

Below are some points to consider and suggested protocols for worming and pasture management.

  • Worm ALL horses on your property every 6-8 weeks (or as directed by the specific product label). This is especially important in Foals, Mares and yearlings, as these animals are most susceptible to infection. Foals should be first wormed at 6-8weeks of age.
  • DO NOT UNDERDOSE If possible, get an accurate weight on your horses by weighing them on scales or using a weight tape. If you are unable to weigh your horses, estimated weights should be rounded up to the nearest 50 kgs. All worming products have a wide safety margin, so it is safe to dose them a little higher. The use of sub-optimal doses of worming product will only promote the development of worms that are resistant to the worming products available. There are only a finite number of different worming product types. Once resistance is established, we will have no means of treating worm burdens.
  • Regularly alternate the type of worming product used This reduces the risk of resistance to particular products developing. When selecting products to alternate with, try and use ones that contain different drugs. E.g. If you used Ammo Allwormer paste for horses, which contains Abamectin & Morantel Tartrate, 8 weeks later try Equest Plus Tape Long Acting Horse Wormer and Boticide Gel, which contains Praziquantel & Moxidectin. Followed by Equimax Oral Paste for Horses, which contains Abamectin & Praziquantel.
  • Use feed bins This will prevent contamination of feed with infective larvae from the pasture.
  • Pick up manure from paddocks 1-2 times per week This will reduce the number of infective larvae available to contaminate pasture.
  • Spell Paddocks Where possible, rotate the paddocks grazed, allowing them to spell for at least one month – Spelling paddocks will reduce the number of infective larvae in the pasture. This helps break the cycle of re-infection
  • Harrow paddocks after removal of horses Infective larvae dry up and die when exposed to heat and sunlight. Harrowing paddocks breaks up the manure and exposes more of the infective larvae to the heat and sun. This helps to further reduce the number of infective larvae in the pasture and helps break the cycle of re-infection.
  • Rotation grazing with sheep or cattle This is another way of reducing the number of infective larvae in the pasture. Horses and sheep/cattle do not share the same types of parasitic worm species. By grazing cattle or sheep in paddocks, these animals ingest the infective larvae, but these larvae die and are therefore unable to reproduce. These animals therefore act to “clean up” the infective larvae from your pasture.
  • Conduct routine faecal egg counts Faecal egg counts can be performed on faecal samples collected from you horses. Egg counts allow us to assess the current worm burden and give us an indication as to whether the worming products and pasture management used are effectively controlling the worm burden in your horses. Regularly performing faecal egg counts (every 6 months) can allow you to strategically worm your horses, so may allow you to worm them less frequently.

By introducing as many of the above mentioned steps as possible, you will achieve good parasitic control, whilst minimising the development of resistance to worming products.

If you have any further questions about worming your horse, please contact us.