A guide to aging the horse by its teeth can be found as the answer to "How can you tell a horse's age by its teeth?" below>
Save those baby teeth for the tooth fairy! - Professor Roadapple.
A foal's first teeth begin to appear within the first week of its life. The central incisors are the first to erupt followed by all three sets of premolars appearing the following week. The second set of incisors come in 2 weeks later (at 1 month), and then the third set erupt at 6-9 months. By the 9th month, the foal will have a complete set of 24 temporary teeth. About that same time the adult or permanent teeth will begin to appear starting with back molars. More molars appear at 2 years, followed by new incisors half a year later. Also at 2 Â½, the first and second premolars appear. At 3 years of age the top jaw's third premolars erupt with the lower ones coming in almost 6 months later. At 3 Â½ the lateral incisors and third molars come in, at 4 Â½ corner incisors, fourth premolars and canines come in. Finally at age 5, a complete set of 40 (female) or 42 (male) adult teeth have come in.