diagnosis ideas?

My friend just bought a new horse so she and I could go trail riding together, and we have noticed that there is something strange about her legs. When she stands, her front right leg quivers. This only worsens when someone is on her. I have narrowed it down to something being wrong in her cannon bone or knee, but I'm not quite sure because whatever it is, it's a very old injury. What makes it worse is that we really don't know what this mare did in her previous home. My friend picked her up dirt cheap from a place that just takes horses and turns around and sells them... so there could really be any number of things. The leg does not produce heat and is not swollen. She is over at the knee and I know that this can cause a horse to trip and stumble... but she is only slightly over and has very upright pasterns and otherwise good conformation. Today she was trotting in the round pen with no one on her and her leg just gave out, causing her to fall down and hit her head pretty bad. I am not very familiar with common lower limb disorders that can be caused by sprung knees, so does anyone have any ideas what this could be? We were kinda thinking it could have resulted from a bowed tendon.... but there is no lameness or swelling. She has full rotation and no pain, however her knee does occasionally grind when manipulated and she has an injury on the cannon bone that resembles a splint or a callous on the bone. Any ideas would be great!

Since your friend got such a deal on him she should be able to spring for a vet check. Sounds like she has some serious weakness in the leg. I'm not sure if I would be riding her much until you get it checked out. Hopefully is is something that can be "healed". It is dangerous to ride a horse whos leg gives out if you aren't able to throw yourself away from a falling horse . Not the least you may be doing more damage to the leg.

She has only been ridden twice, and she will be on stall rest until she can be vet checked; but the vet is half the problem! We live in the middle of the desert and the nearest vet of any kind is about 60 something miles from the horse and he won't make calls to the house... what's even worse is he's not a equine vet, he's a small animals guy who has taken on horses because no one in the area has a choice. The nearest actual vet who would be able to ultrasound and radiograph her is about 120 miles away, and until we get a hitch for her truck and fix the trailer she just got, we can't take her anywhere. So I was hoping someone had some clue what is was before we have her evaluated, maybe a different feeding program? I think she might be deficient in some minerals like calcium but.. who knows. I just want to make her comfortable and keep her from injuring herself.

Among other things I would check her hoof balance. Also check farther up, shoulder, withers for soreness.

Unfortunately this horse was probably sold due to this issue. You may have to haul her to the vet 120 miles away in order to get a diagnosis. I wouldn't shut her up in a stall tho, that rarely helps imo.. In a stall you have the problem of constant turning, this could be pretty stressful to a damaged joint.

Sorry you are so far from a vet, how frustrating. I kind of thought popped knees or a bone chip. Check http://www.thehorse.com/ViewArticle.aspx?ID=2784&dpt=4 see what you think.

Here is another interesting one...Hope they open if your not a member. http://www.thehorse.com/ViewArticle.aspx?ID=2784&dpt=4 Let me know if they don't and I will email them to you if your interested

You could be dealing with pain, neurological deficit, or muscle disorder. Without the vet exam, it's all just a guess especially from people who can't see the horse. I would not ride this horse and would put her on small paddock turnout. Stalling is a bad idea with some issues so err on the side of caution, don't let her have room enough to run and act crazy but don't make her stand in one place all day either.

I would definitely go with the time and expense of seeing the equine vet because there are just too many things that can be wrong and a small animal vet is not going to be as up on current issues in horse medicine.

Thanks for the articles, I agree that it is probably a bone chip. I know my friend just called the last registered owners to see what they had to say about her. It's interesting because the first person owned her for 15 years and the second for only 6 months, so I believe there must have been something wrong with her to just turn around and get rid of her like that. But I guess I will find out when she calls me back. Until then we will have to wait until we can take her to vet. :( still makes me feel bad though.

At least the prognosis is fairly good if it is a bone chip. Hope you can get her to the large animal vet soon. Keep working on that trailer! :)

UPDATE!

Well she was finally checked, and she has neurological problems that cause her to wobble. That's what causes her leg to shake and also why she has balance and stumbling issues. So she just gets ridden lightly now while my friend awaits the birth of the foal. After that, she is going to give the horse a refresher course and her 13 year old sister will use her for pleasure riding. Kinda interesting how the whole thing turned out.

Did the vet give any advise as to what can possibly be done to help the horse out or what might have caused it? Glad you finally have an answer. :)