If you're thinking of buying an OTTB (off-track thoroughbred) straight from the track to re-purpose as a sport or pleasure horse, you should be aware that many of the horses are being sold because they've been injured during racing or training. This does not mean they are not capable of being rehabbed and used for another career. Many horses recover perfectly well from their racetrack injuries, and although they are not suitable to race again, are sound enough to make excellent pleasure and sport horses. However, there are others whose injuries do leave them perpetually lame. When you shop for an OTTB, it is important to know a bit about the two most common injuries they suffer so you have a better idea of how a particular horse will recover.
A bowed tendon is a tendon that has been partially or fully torn. This usually occurs in the front legs of race horses--in any of the tendons that run along the back of the cannon bone between the knee and the ankle. Bowed tendons take several months to heal. Often, a horse will be sound when the tendon is healed, but he will be at an increased risk of pulling it again. Thus, many owners choose to retire their horses from racing when they bow a tendon.
If you are looking at an OTTB with a bowed tendon, when you have a pre-purchase exam done, be sure to share with a vet, like those found at http://www.1stPetVet.com, what you plan on doing with the horse. This will allow the vet to tell you, with more confidence, whether or not the horse will be suited for the career you're planning for him. A horse with a severe bow may be able to recover to the soundness level required for a weekend trail horse, but will be at risk of re-injuring a tendon as a dressage horse or upper level eventer. Likewise, a horse with a slight bow might be able to make it as an upper level eventer or fox hunter if he is rehabbed properly. It is tough for the average horse person to determine the severity of a bow and its repercussions, so always have a horse with this injury looked over by a vet so you know what you're getting into before you buy.
Osselets are bony growths that often appear on the front fetlocks of racehorses as a result of heavy work. When the osselets are new, they are typically sore and puffy; they will cause lameness in most horses. If looking at a horse with new, sore osselets, you will certainly want to have them looked over by a vet. There is a chance the osslets are hiding a bone chip, which could cause ongoing lameness issues and require surgical repair in the future. On the other hand, the vet may find that the osselets are very minor and won't cause severe soundness issues once they heal.
If you're looking at an older, 6- or 7-year-old OTTB, he may have some osselets that have already been given the time to harden and heal. If such a horse appears sound and has been racing sound since the osselets healed, having it vet checked is not so important unless you plan on using the horse for a very demanding career like upper-level eventing or fox hunting. However, if the horse is expensive, or you sense that the horse may be even the tiniest bit off on the leg with the hardened osslets, you will want to have a vet check done to rule out the possibility of a bone chip.
When buying an OTTB straight off the track, it's important to remember that a horse with these common injuries is not necessarily "junk" or destined to life as a pasture ornament. Each case is different, and a vet can conduct a pre-purchase exam to tell you more about how the horse's specific injury is likely to heal and affect his future usability.