The highest race horse speed ever recorded was 43.97 mph (70.76 km/h). The smallest horse in the world is just 17 inches (43 cm) tall and weighs 57 lb (26 kg). Horses can sleep standing. The Roman Emperor Gaius Caligula made his horse a senator. An individual horse has a peak power output of 14.9 horsepower. In the UK, all horses, ponies and donkeys must have a horse passport. The practice of eating horseflesh is called hippophagy. Dogs have 13 blood types, horses have 8, cows have 9 while Humans only have 4. The Horse Head used in the movie "The Godfather" was real. Over 8 million horses died in WW1. Of those who survived, most were sent to Belgian butchers, being regarded as unfit for any other purpose. Horses cannot throw up. Animals, including pigs, horses, and even insects, could be tried and convicted of crimes for several centuries across many parts of Europe. Traffic in central London moves at the same speed as horse-drawn carriages a century ago. McDonald's drive-thru staff won't serve people if they come on horseback. The modern British army has more horses than tanks. In 1923, a jockey suffered a fatal heart attack but his horse finished and won the race, making him the first and only jockey to win a race after death. In the early years of the 20th century, horses were causing so much pollution with their poop that cars were seen as the "green" alternative. California banned the sale of horse meat for human consumption in 1998. A horse's hoof is technically a single toe, so horses run on their toes. Riding a horse while intoxicated is considered a traffic offense in Colorado, U.S. Darwin suggested the appendix may have been used for digesting leaves. This theory is supported by koala and horse appendixes which do just that. The horses in Olympic equestrian events have their own passports and fly business class. Horses can be trained to use symbols in order to tell humans what they want, a study found. Horse-eating is called Hippophagy. Horses killed more people in Australia from 2000 to 2013 than all venomous animals combined. Avocados are toxic to horses. There's a monument to honour the almost 1 million Allied horses who died during WW1.