In the training world there seems to be a constant argument over what age to start a horse under saddle. There are plenty of posts on this already online, but I thought I would try to put together a few valid thoughts on the subject.
I’ve had many people tell me that a horse’s knees closing are a good indication of a horse maturing and being able to start working under saddle. I think this is a good start for sure, many problems are found in the legs of horses if started too soon. But after doing some research, I found that the back is more frequently the cause of injury before the legs. According to one website (sited below) a horse’s growth plates convert to bone starting from the bottom of the animal and working up. That means that a horse’s knee will be closed and solid between the ages of two or three, but everything above that are still forming together to become solid bone. The growth plates in the pelvis and hock don’t finish converting to bone until the age of 4 and they don’t finish forming in the vertebral column until 5! This means that no matter how in shape your young horse is, they will still have these weak areas until they are fully mature.
Though many bones have finished forming by three years old, it’s important not to overwork your three year old and to know where the problems could come from. A young horse could easily get sore in his back and then start compensating for that pain in other areas. There is a difference between educating a horse to carry a rider and really putting him to work. You can teach a horse how to hold himself, and how to keep a sane mind under saddle, but be careful of the workload you give them at a young age. That is, if you want your horse to live for a long time and pass vet checks down the road.
I’ve heard some people say they feel more comfortable starting a horse at a younger age because of their mind and size. They believe they are more open minded and easier to find control on. I personally disagree with this, and I’ve found many others do as well in my internet search. I’ve found that older horses are more mature in the mind, and tend to be less flighty in general when I start them.
All things have balance of course. Take each horse in stride and do what is right for that horse. Just be mindful of where a young horse is still growing in order to help your horse stay as sound as possible throughout his life.
(Photo credit to Hoofie being started in 2013. She was three years old at the time and one of the easiest horses I ever started.)