Had this problem for awhile but thought it was just because of how terrible the horses in Skyrim were, what with every little hill on the road sending them flying. The smallest fall kills my horse instantly and forces me to reload my save every single minute, and an arrow from a bandit will also kill it instantly. I download the essential horses mod and tried a couple others but none of them work, probably because of compatibility issues. I've also reinstalled the game and uninstalled all my mods but that didn't work either.

Can someone help? I'm pretty sure it isn't natural for my horse to die in one hit because it used to take 2-3 hits to die awhile back.