Humans only have 206 bones in their bodies. Horses have over 100 feet of intestines. If a horse rolls around on the ground they can twist their intestines around inside and kink them up so they won't work. This is very dangerous for a horse and that's why people always try to stop them from twisting around on the ground.
Horses have pretty delicate digestive systems overall.
In fact, they aren't supposed to eat or drink anything for at least 30 minutes before or after any exercise. The hagfish is different from other fish in many ways other than its unappealing name. In place of jaws, the hagfish has an oral sucker in the center of which is the mouth cavity. They get their food by attaching to other fish by their suckerlike mouths and breaking through the skin to eat the fish's internal organs. The Lappet-faced vulture is even more creepy than most vultures.