I mentioned teething in the last post. So, do horses teeth? At what age?
Foals are born with no teeth at all. Their incisors appear within a week, and the full set of baby teeth is present by the time the animal's six months old (the order is central incisors, intermediate incisors, premolars and then corner incisors).
The young horse sheds these baby teeth in the same order they arrive, starting when he's about 2 1/2 years old. A horse is not through teething until four and a half or so (I had a horse who was five and still hadn't got his full corner incisors in). The baby teeth are pushed out by the permanent teeth (occasionally, baby teeth don't shed properly and a dentist needs to remove them).
So, foals under six months are teething and so are adolescent horses between 2 1/2 and 4 1/2 years old. As horses of that age are often ridden, teething issues have to be watched. And, like any other animal, a teething horse appreciates something to chew on.