Hi, I am seeking the collective wisdom here please. I am looking at a very nice filly to purchase. She apparently had a tight ligament that prevented her knee from flexing properly as a foal. Now as a three yr old I have seen a video in which she still appears to be bobbing her head and favoring that knee. I do have a ppe scheduled but in the meantime I am trying to educate myself.
1 How common is this condition in foals? Common just not disclosed, not common?
2 While I am sure severity is a factor how likely is to be resolved with exercise?
3 Is it likely to affect performance, particularly low jumping dressage hopefully to 3rd maybe even 4th level? Not just a trail horse. 
I am trying to educate myself, at this point I don’t even know what questions to ask the vet to look for. thank you.
Contracted tendons/ligaments at birth are not too uncommon, usually treated successfully with veterinary intervention- tetracycline injection, and stall rest, and warmth. If a soundness problem persists as a 3 yr old, it may or may not be related to this situation at birth. Mature horses who are over at the knee CAN be sound horses. If you are having a PPE done, your vet will examine, possibly xray where they think an issue might be present. But if you are seeing a horse who does not look sound on a video, why are you paying a vet to do a pre-purchase?
Flex (bend) or extend (straighten)?
Contracted tendons prevent a leg from straightening all the way. Most of the time, that resolves simply with some time and the ligament growth catching up to the bone growth. Sometimes it requires dietary intervention, and occasionally surgical intervention.
When she’s standing, does the leg fully straighten
Common enough I wouldn’t expect most people to mention it unless there was surgical intervention
She’s 3? It’s unlikely what happened as a foal, if what you’re describing was normal contracted tendons, has anything to do with why she’s lame now. But if it is, and she’s 3, I wouldn’t touch it with a 10’ pole
Welllll yeah, if she’s currently lame as a result, 3 years later
Cart before the horse I wouldn’t even be doing a PPE on a lame horse. Find out from the seller why (they think) she’s lame. if it sounds reasonable, then go back later and look at her once she’s sound. Once. She. Is. Sound. And only then, do a PPE with insistence to your vet - not the seller’s - that she pay very close attention to that entire leg, hoof to shoulder.
Nancy and JB, thank you both.
After I posted I rethought some of what I had been told, and the short version is I had decided to cancel the PPE as I got thinking along the same lines as both of you mentioned, why start with a lame horse. lol
Again, thank you both for your time.
