I just saw an ad for a two year old who at this time is 15.2 and has 120 days riding??. I am desperately searching for a tall horse and I have vetted nine horses that failed mostly due to juvenile arthritis in the hocks. They ranged in age from 5 to 10. This is heartbreaking for me because I find it very hard to walk away from a five-year-old horse with terrible arthritis and wonder where is this poor guy is gonna end up? What is causing all this arthritis? Is it riding them too young and too hard? Is there something in the feed or is it genetics? Because I'm 6 feet tall I look for tall horses and wonder are they being started too young when they are still growing and building bone? 

I firmly believe it's a combination of starting them too early, not enough turnout, and too much alfalfa. And all the inbreeding.

that's probably it

They are to young at 2. Greed on the seller and buyer with no remorse what they will be like when they are 15 years old. 

I am the queen of the tall horse.  Everything I breed seem to end up 15.2 or over.  I don't feed a lot of protein or alfalfa.  And I'm always behind.  I have two three year olds that are pretty much green broke and I haven't started on barrel pattern.  Don't give up they are out there. 

I know a couple trainers that I would allow to put 120 days on a 2 yr old.  Those trainers are master trainers and very knowledgeable about lameness, weakness and limits a horse has and all three of those words are important.  I feel that 120 days would be a waste of money on a 2 yr old.  60 tops and most of it is not riding but driving.  Usually 30 days is enough to see what a colt is about and a lot of that is not riding.  I just want to know if I should feed it another year.  Then they get restarted at 3