Starting to jump young horses.

Question
Someone I know has been riding and jumping 3-5 year old warmbloods, specifically Hanoverians. As 3-5 year olds they claim to be jumping 4'+. What damage can be done at such a young age considering warmbloods are known to develop much slower than say your average TB. What as far as joints, knee closing, hocks, and horses spirit & confidence does jumping these babies these large heights do? Thanks.

Answer
Hello Nicole!
Alright...well you are right, Warmbloods do develop much slower than other sport horses. A warmblood should only start being backed at the age of 3, for their knees only close at that age. Hanoverians however, develop faster, so they can be free jumped up to about 3 feet. I wouldnt go any higher than that at the age of 3. At the ages of 4 and 5, start getting them to jump higher...Anyhow, to answer your question, well for the Warmbloods, jumping 4 feet at the age of 3, is a very bad idea. It can eventually cause lameness, and/or arthritis, if the owner isnt careful with what she does with the horses, and if she or he doesent be careful with the amount that they jump their horses. If horses start so young, they might just get bored of jumping later on when they get older. Like i said before, it can cause serious damage to their joints, knees, and pretty much their whole legs. If the person you know is just free jumping them, well i wouldnt worry about it to much, unless she is doing an exessive amount of it. If she is on them when she is making them jump at the age of 3, thats a different situation, and it can be very dangerous.
At the age of 5...they are fully developped... so as long as this person has boots on the horses, they should be fine.
Thank you for the question!
I am more than happy to help!