If you are the owner of a colt, you have undoubtedly been asked if and when you are going to geld your youngster. In fact, you may have even found yourself wishing you’d had a filly, just to avoid having to make this tricky call. As with most horse-related issues, there are lots of opinions on gelding – who should do it, when to do it, if it should be done at the clinic etc. Before we go on, it is important to say that there are no real right or wrong answers. The best thing you can do is to familiarise yourself with the entire process of gelding and then make the best decision based on your colt and your individual situation.

The nitty-gritty

Gelding is also known as castration or cutting. The scientific name for the procedure of gelding is orchidectomy – ‘orchid’ meaning testicle and ‘ectomy’ meaning to remove. Therefore, orchidectomy literally means ‘the removal of a testicle’. Gelding in any species involves the removal of one or both testicles and associated structures, such as the epididymis, and part of the spermatic cord. The spermatic cord is the tube-like structure that contains the blood supply, ductus deferens and nerve supply to the testicle.

Don’t cut corners

Although gelding is one of the most common surgeries performed by veterinarians, it should not be taken lightly, as if not planned and monitored carefully problems can occur. Only a registered vet can perform the procedure, and you must be prepared to do the after-care advised by your vet.

What is the best age?

Horses can be gelded at any age. Foals can, in emergencies, be gelded at just one day of age, and stallions can be gelded well into their twenties. However, at these extremes of age, the procedure is normally being performed due to a medical emergency or serious medical conditions such as:

  • A scrotal hernia: This is where the intestine herniates into the scrotal sac. This can be a medical emergency.
  • Cryptorchidism: A condition where the testicles have not properly descended into the scrotum. In extreme cases testicles may stay in the abdomen of the horse, instead of descending towards the scrotal sac. Testicles that have not descended correctly and are at increased risk of becoming cancerous. Usually the stallion in these instances, will have all of the usual stallion behaviours, but will not be fertile as testicles within the abdomen are not kept at the correct temperature for sperm production.

In usual cases, where the colt is healthy and there are no special circumstances, most vets feel that castrating at a young age, under the age of one year old generally, is best. This is because colts of his age have smaller testicles that are easier to remove and therefore the procedure has less chance of causing severe bleeding post-operatively, and the risk of wound infection also lower.

Why geld?

The testicles are the organs that produce testosterone. Testosterone is the hormone predominantly responsible for creating stallion-like physical features and behaviours. Removal of both testicles, and hence the removal of the testosterone-producing organs, usually helps to rid the horse of stallion-like behaviours, that can be difficult to manage, such as mounting other horses, masturbation, aggression and fighting. However, if castration is not done until late and/or if the stallion has been used to breed with mares, is may not be possible to eradicate all stallion-related behaviours by gelding, as these behaviours have become habits for the horse.

Many owners wait to castrate their horse until he becomes a problem management-wise, usually at around the age of two- or three-years-old. This tends to be because owners want to give their colts as long as possible to develop a masculine appearance under the influence of testosterone, such as a big neck and stockier build. Some owners also believe that stallions perform better than geldings in competition, so they wait to see if the horse is worth keeping as a stallion. However, there is little evidence to suggest that stallions do perform better in competition, so unless you are wanting to breed with your colt later on, it probably isn’t worth keeping him intact for the potential show results.

Gelding for height

If a horse is gelded early in life, it is widely believed that he will grow taller as the closing of the growth plates in the legs is delayed due to the lack of testosterone. There is a wide variety of opinions on this in the literature, and while it has been shown to be the case in various other species, there is a lack of evidence absolutely confirming that this is the case in horses.

When to geld

In South Africa, gelding in winter is certainly preferable to gelding in the summer months when midges and flies can be a real problem during the wound-healing process. It may also be a good idea to geld your youngster a couple of months prior to his first competition outing as his behaviour is likely to be more settled, and mares may prove less of distraction!

So, as you can see, there are plenty of factors to consider but ultimately deciding when to geld your colt, if at all, is a very personal decision, and one that is well worth having thought out in advance.