I was riding my best horse somewhere when my game crashed. I reopened Minecraft and opened the same world, but I was no longer on my horse. I was in the exact spot where I was on my horse (even inventory contents were the same), but the horse is nowhere to be found. This has happened to me twice, and I keep having to find new saddles and fast horses. The second time was the same as the first, game crashed and I end up on the ground with my horse gone. My game doesn't crash very often, but as there is no way to see it coming, I am not sure how to prevent this issue. I hope this helps!