Yes! Horses can roll over. Not all horses can roll completely over but many can. Whether a horse is able to roll completely over depends on conformation, muscle condition, balance, and the surface they are rolling in. Many horses are unable to roll over on any surface and will roll on each side separately. There is nothing wrong with a horse that cannot roll completely over- many make excellent performance horses regardless whether they have the particular ability to roll over. You should pay attention to your rolling horse, however. If your horse used to roll completely over regularly, and suddenly stops, it may be a sign of a misaligned spine or other injury.