In the process, dentin is exposed. At this point, the tooth is level. Level teeth appear with a complete ring of enamel around the tooth and darker yellow dentin exposed in the center. From eruption dates, in wear dates, and leveling of the first, second, and third incisors, we can determine within six months ages up to five years. After five years, experts use other criteria to determine the age of the animal.
All cups are present by age five.
Cups of the first, second, and third incisors are worn flat at six, seven, and eight years, respectively. At age seven, a hook appears on the upper third incisor. This is present in only 60 percent of horses. It reappears at 11 years of age. When aging a horse, it is important to be wary of fraudulent practices.