I have one. He’s 17 years old this year. It’s the second one I’ve dealt with, the first one was 50 years ago (wow, scary to write that). No one had any idea at that time what I was even talking about… that the horse fell asleep, wouldn’t lie down, then fell down CONSTANTLY. He did it at Spruce Meadows, in the East Meadows barn, tacked up for his class when I went back to my tack box for something and my Mother was holding him, and a bunch of schoolchildren were being taken on a barn tour right past him. CRASH!!! No children were hurt. But THAT’s how fast it happened. He went to his class that day with blood on his lip, where his nose had hit the pavement in the barn aisle.
At home, he would put his head and neck over our LOG fence in his paddock, or over the VERY STRONG stall door, and hang himself there, to hold himself up. At horse shows, I’d try putting stable bandages on, then figure 8 bandages over his knees, to try to put pressure on the fronts of his knees to hold them from collapsing. The vets looked at me like I was crazy, and shrugged. I wrote to Dr, Malcom Mackay-Smith about this, but he had no helpful input. This horse was competitive at the 4’6" and up to 5’ jumper divisions… for years. And I was a kid. He started doing it as a 3 year old.
The horse was an unraced TB gelding, who we had purchased as a yearling from the breeder, as a show horse prospect when I was 12.
And now, I have another one. Same paint job as the original too… chestnut gelding, four high whites, blaze. (Does that have anything to do with it??? (joke)). The current one is an unraced, home bred TB gelding. Lives a stress free life. Has never been stabled, lives here at home, with his friends and family. He’s turned out to graze at night in the summer months, in a paddock during the day. Free feed top quality hay, and a small amount of breakfast with vitamin/mineral mix. Been to one horse show in his life. Talented. Open sores on the fronts of his ankles in summer, from falling down. I’ve found that putting some vaseline on those seems to help then not get worse and bleed… seems to make them slide rather than “catch” on the ground when they knuckle over.
My current case was at the vet’s yesterday to have his teeth floated. She looked at his ankles, I explained the situation, and she shrugged. Eventually, something will break when he falls. This is what happened to the first edition… we presume that he broke his neck. He was “ataxic” one morning, and put down that day, That was in 1985. He was a horse of note. He made me into the horseman I am today. He was a superstar that I got to sit on.
Good luck with your case, if you have one. I have few answers for you.