Q: I have a six-month-old colt and I’d like Dave’s opinion on the advantages and disadvantages of getting him gelded early (before winter really sets in). I have a friend who says it’s much better to wait until they are yearlings up to about 18 months old. However, he will be grazing with two mares (including his mother).
Sam, Northland
Vet Dave replies
From a practical perspective, vets prefer to geld when paddocks are not muddy and when there are not too many flies around, to reduce the potential for any complications. This usually means autumn and spring are the classic time.
That is not to say that we don’t geld outside of these periods, but that most of our geldings are compressed into this period.
For this answer, I am assuming that your colt has two testicles, as gelding a rig is a different kettle of fish both surgically and timing-wise. If you are not sure, then it is worth checking – better now than when the vet has him nicely sleeping in the paddock and finds only one.
The benefits of gelding at six months are that the colt is less likely to have developed any behavioural problems associated with male hormones, which will sometimes translate into a learned behaviours. It means that you have no worries about running them in a mixed herd, and the potential form them being fertile or sub-fertile prior to being gelded.
It also means that you don’t have to have any special facilities for dealing with a hormonal colt at 18 months of age. No vet enjoys trying to get a needle in a poorly-handled 18-month-old colt who is now 350-400kg, compared to his 150kg six-month-old counterpart. There also seems to be less swelling generally with the surgery and less post-operative bleeding in younger colts because everything is smaller, so there is less surgical trauma.
The benefits from gelding later are that you get some of the desirable traits from the male sex hormones coming through in the appearance of the colt. The older the colt is left, the more pronounced these will be.
If these are desirable traits in your eyes, then you need to have the appropriate facilities to handle and train such a horse alongside any other horses in your herd.
An un-gelded colt will tend to put more effort into muscle growth and less into height, so an early-gelded colt will typically be slightly taller but finer than his late-gelded counterpart with the greater the age gap in gelding, the more noticeable the difference.
Colts will start hitting puberty at around 50-60% of their final body weight with the timing of puberty influenced by increasing day length (the same factor that induces mares to cycle in the spring).
If you are running him with two mares I would suggest gelding him early to avoid any concern that he may mate, bully or otherwise interfere with these mares as he starts to get a taste of his impending male hormones switching on.
