Had one removed from a just turned 2 year old. The vet told me, it might make a difference, it might not. He said, There are plenty of horses that have them and never have an issue with them. However, it can be an issue with others. Especially with younger horses, who might have a chance of making some good stakes money as a 2 and 3 year old. Would not be good if you have a nice horse coming up into a stake race and then it does becomes a problem because if it was not done, and then you have to stop with him, and miss races. Rather be safe than sorry, or roll the dice and save the money?? You never know, its another gamble in the game. Seems as most of the big breeding farms do them, they mention them and the date they were done at the yearling auctions.