Preparing Yourself For Horse Ownership (Part 20) – Aging A Horse By Its Teeth

When a horse is registered, the person registering the horse (typically the breeder) will mark down when the horse was born on the registration papers. This makes a fool proof way to determine the age of a horse, but not all horses are registered or sometimes horses are separated from their registration papers when transferred to new homes, and it can become a bit of mystery how old the horse actually is.

Aging a horse by its teeth may seem unlikely, but it is one of the best methods for determining how old a horse might be.  Outside factors such as abnormal teeth wear from things like cribbing or injuries to the mouth like a kick may affect the accuracy of the teeth reading, but overall looking at the teeth is a common practice in determining a horse’s age. 

Age is determined by looking at the 12 incisors at the front of the horse’s mouth.  A horse has 6 incisors on the top of their mouth and 6 on the bottom.  Young horses are the most accurate to age based on the eruption of baby teeth, loss of baby teeth and then the eruption of permanent teeth.  The first two teeth to erupt on a horse are the very front two incisors on the top and bottom jaw.  These erupt shortly after birth (usually in the first 10 days).  At around 4 weeks of age the foal will have 4 incisors on the top and bottom jaw as the next front teeth emerge.  When the foal is 9-12 months of age it will have its full set of incisors with 6 on the top jaw and 6 on the bottom jaw.