First off- this post does not pertain to any of my horses. This post pertains to a friend's horse. I have an intense interest in horse health and the causes of certain behaviors, so I thought I'd get people's opinions. That way, if I ever see another case like this in one of my horses, I might have some idea of what it is caused by.
Anyway... The horse in question was very flighty after first bought. She seemed to spook at everything, and was very tense in general. We all thought that this might be because she was new, used to being on pasture 24/7 (even though she had a run extending from her stall), etc. After a couple of months, and constant turnout and handling, she still had not quieted down. She was jumpy, had bad ground manners in general, and spooked at things that she had walked past every single day. When she spooked at an event, and dumped her rider, she was sent to a trainer.
The trainer is now telling my friend that the horse has balance issues, and is still shying at random things, even after being ridden almost every single day since September. Apparently, the more they work with her, the weaker she seems to become. They're thinking that this might be related to her spookiness.
At first, the horse's issues seemed to be related to respect. She seemed to have issues respecting her handler, but she was always good with the farrier, and never got aggressive. She just got scared and flighty.
To me, this sounds like it might be escalating into a health issue. Does it sound that way to anyone else? As far as I know, they haven't tested for anything. I've heard that EPM can affect a horse neurologically. Any ideas?