bowed tendon

Question
i just recently got an off the track thoroughbred that had bowed his tendon last year. he's only 3 right now. the bowed doesn't not look severe and he's been cleared by a vet. i'm looking to work him back to do dressage or maybe low level eventing, but i don't want to rush the rehab. any thoughts on how to go about restrengthing it?

Answer
Stefanie,
Unfortunately you can't really "re-strengthen" a tendon, at least not like you would a muscle.  A really simplified explanation of why follows:
Think of the tendon as composed of a myriad of tiny fibers, all aligned in the same direction, and pretty darn elastic.   When a horse bows a tendon, basically he has torn some of these fibers.  How many of these fibers are torn, and where they are torn determines the severity of the bow.  (A high bow is far better than a low one, due to the amount of stretching the area needs to do.)  
Anyway, when the tendon fibers heal, they don't all heal in perfect alignment, like they were originally.  Some will be criss-crossing the area of the injury, rather than going up and down.  As the horse moves and works, these criss-crossing fibers will tear, and new fibers will lay down, in all directions, and this will keep on until most of the fibers are once again aligning the right direction.  But the healed area will never be as elastic as the original tendon was, since scar tissue is not very elastic.  Most estimates guess that at best a horse will regain 80% of the original tendon strength in the damaged area.  This isn't something that you'll likely ever notice doing dressage or light to moderate eventing, though.  Especially if it doesn't look severe, as the damaged area was probably very small.
My best advice is to monitor the area of the bow very carefully for heat or swelling.  As the fibers continue to remodel in response to the new work, your horse may experience some minor heat and/or swelling.  If that happens, just ease up on him a bit, and watch carefully.  Don't stop altogether, otherwise the fibers will not heal as much in alignment, but ease up on the training until the area settles back to normal, then step up the training a little notch at a time.

Good luck with your new friend,
Stephanie Frost
www.alchemybloodstock.com