Sorry, I can't read through this whole post. But you can answer or not, it's up to you :) Has your vet done blood work and checked her Vit E levels? Does she have any stiffness when stretching anywhere through her body? Kissing Spines? Saddle soreness? Neck problems?
If it was neuro, I don't think horses can just "adapt" since it is misfiring signals in the brain and neuro system. Maybe I'm wrong, but it doesn't seem possible to me. Usually hind end neuro problems are caused by a neck injury.
Thanks for the post. Kissing spine is interesting to me. I just had chiro out and she had nothing going on in her neck. She never shows any signs of soreness or being unhappy. She is always quite aloof and goes along with everything. She was only started under saddle this past summer and has been trail riding over the past few months. She showed the abnormality when I first purchased her as a two year old and has the same gait whether she is under saddle or not. When I purchased her, I noticed something different, but wasn't sure if it was anything to be concerned with or not. I had the vet look at her before taking her. The vet said she was butt high and a draft cross....she seemed to be growing into her legs and was in a growth spurt. Since then, more vet visits to look at her, farriers, chiro, massage therapy, trainers....nobody can seem to pinpoint anything at all. I was concerned with wobblers....she passes all the physical tests. She is very flexible in her neck, does lateral movements, backs up fine, can walk blind-folded, does not do circling with her legs in a tight circle, good tail tone, doesn't show any type of misfiring at the walk. Some people thought she was trying to gait. Her cadence/rhythm is way off at times, but not always. When she walks, she walks base narrow, then may take a step or two wider, then back to base narrow...she seems 'loosy goosy' in the behind. At the trot, she smacks her hind legs down, this I guess was why the recent vet diagnosed her with stringhalt. She also crosses over with her legs. When she steps out of the trot to the walk she goes from base narrow out to a wider stance maybe?...for balance?...I think. At the canter she sometimes gets a good rhythm and she looks fine, and then something happens and her legs go wonky. When slowing down, her butt and legs go underneath her like she is doing a reining stop. It looks like if you were standing with your knees locked, and someone did the karate chop thing behind your knees and they gave out. It looks like the scarecrow from the Wizard of Oz. The weird thing is that it is all not consistent. It almost looks like her fetlocks lock up sometimes.
I am going to try and get some video with the help of a friend while I lead her so people can see. Nothing has changed since I got her and started riding her. I ride her almost everyday from just riding around the ranch to trail riding for a couple hours. There are times when she was hesitent with something, like an incline on a trail, but she seems to think and figure it out and then does not hesitate the next time. I don't over push or expect too much. If it seems like a situation that may not be good for her, I get off and walk her over it. She has never fallen or anything such as that.