Twice a year the equine dentist comes to check the horses' teeth. They feel the molars to check for sharp edges, and if they find them, take out a very large electric tool and file away. Needless to say, the horses do not enjoy this process at all (who would!) and so must be given a horsie sedative to take the edge off. Some of them look like they might just fall down, but so far, no one ever has. Phew!

p.s. A horse's age can roughly be detected by the front teeth and incisors......hence the 19th century saying to "never look a gift horse in the mouth".