This was a rather tragic mystery that happened to my first horse about 10 years ago.
The vet hadn't experienced such a thing, and consulted with other vets who couldn't explain it either.
So, my question is, has anyone else experienced this before or have an idea as to what caused it?
About my horse- I found out that he was older (about 18) at the time of his death (I was told he was 6 when I bought him, so I assumed he was around 10 when he died). He had been in this particular pasture for a little over a year with 2 other mares. Neither of them had any issues, so I am thinking that it wasn't a toxic plant, etc.
It was a very, very hot year, and was in the middle of summer when he died. We had numerous days of 100+ temperatures, which I can't say helped any. There was always water available, they were getting fed 2x a day (what exactly, I don't remember). My horse had always been one of those horses that were a bit hard to keep- his weight fluctuated frequently, but not drastically. I live in Bryan, TX.
Day 1: Looked normal. Acted normal.
Day 2: I noticed he seemed to be loosing weight, so I upped his feed a bit that evening. Still acted normal.
Day 3: He wouldn't come up, he stood under a tree and nickered at me, but didn't budge an inch. I went out to him, feeling like something was wrong, and was completely shocked.
He had dropped all weight he had (and he wasn't a lean horse, more stocky), you count count all his bones. Not only that, but his skin was hard, wrinkled and sunken in. Every time he moved an inch, it would crack to where you could see his flesh underneath (he wasn't bleeding), the skin had also begun falling off.
I took him to the vet (took about an hour to just walk to the trailer). He was very anemic, in shock, and his liver tests were abnormal, but beyond that (aside from his physical state) every test came out normal. Do to his condition, she didn't anesthetize him, as she felt he may have not survived to do so.
He spent about 2 months in horsey ICU (mostly kept on fluids, pain medicine, and TLC) before he was stable enough to come home. Just about all the skin fell off his body, though it had started to regrow a little bit. His liver count was better, but still abnormal, and she suggested once he recovered to see about further test to see if there was something such as cancer, etc.
Unfortunately, after taking him home he fell down out of the trailer, and we (myself, several other people and a tractor) could not get him to stand back up on his own four legs. My vet came out the next morning (we tried throughout the night to get him standing) and put him down.
He was put to rest at a friends ranch- he wasn't buried, but laid out for nature to take its course (this is what I prefer, if there is enough room to not interfere with other things). Instead of normal decomposition, his body more or less became mummified (and still is now, several years later).
I'm still rather dumbfounded as to what may have happened. His sudden decline was absolutely bizarre.
He wasn't being ridden very often before all this happened (maybe once a month), and hadn't been taken off the property in probably 6 months.
As its been awhile, there are a lot of specifics that I forget, but if there's any questions I will try my best.