Page 99 - The Mini Horse Magazine 2023 No 1

Being able to pinpoint age within a fairly narrow range can be of use
to owners of unregistered horses or horses whose age is unknown
for any reason. Many health and nutrition management decisions
are directly related to age and dental wear, making it even more
important for all horse owners to have a general understanding
of how a horse’s mouth changes with age. From a historical
perspective, up until recently when organized associations started

keeping birth dates on registered horses, most horse professionals
took great pride in their ability to determine age by examining the
teeth of any horse. Aging the horse by its teeth is not an exact
science, but changes do occur that can help determine approximate
age, and anyone can learn the basics.

INCISORS TOOTH SHEDDING

Horses under 5 years of age go through some At 2 ½ years the horse’s deciduous central
very typical dental changes. With foals a incisors are pushed out of the way as the
good rule of thumb to remember is that their permanent centrals erupt from below. At 3 years
milk teeth, or deciduous teeth, erupt, or come the upper central and lower central incisors have
in, following a simple timetable of 8 days, 8 grown out enough to meet, and therefore, begin
weeks and 8 months. Here is how it works. to grind against one another. This is referred to
Foals are born either without teeth or with four as being “in wear.” These wear patterns will be
central incisors, two on the top and two on the used later in the horse’s life to help determine
bottom. If the central incisors are not present age. At 3 ½ years the intermediate incisors will
at birth, they usually erupt within 8 days. The be shed, and at 4 years of age they will be in
intermediate incisors erupt by 8 weeks and the wear. At 4 ½ years the corner incisors will be
corner incisors by about 8 months. These are shed, and 6 months later, they will be in wear.
deciduous or temporary milk teeth that will be Male horses have four canine teeth (tushes)
shed as the young horse ages. The deciduous located between their corner incisor and the
teeth can be distinguished from permanent molars. Mares will occasionally have canine
teeth because they are wider than they are teeth, but usually these are not as developed
tall and they have shallow roots. Twelve
is he? premolars will also erupt within 2 weeks of appear during the horse’s 4-year-old year. They
and all four may not be present. These teeth
age, three on each side of the top and bottom
should not be confused with wolf teeth which
jaws. However, premolars are typically not
are very shallowly rooted and found adjacent
used in aging horses as they are more difficult
to the first premolar. Wolf teeth are commonly
to view. Other dental changes occur in yearly
increments and the young horse’s mouth extracted as they may interfere with the bit.
Canine teeth are not extracted under normal
changes like a child’s does as they shed their circumstances. (Refer to Utah State University
deciduous teeth. This systematic shedding Extension’s Equine Dental Care fact sheet for
of deciduous teeth is what we use to “age” more information on dental care.) Horses are
horses until they have all of their permanent considered to have a “full mouth” at 5 years
teeth at 5 years of age. old, which means that all permanent teeth have
erupted and are in wear.

Miniature Horse Magazine • Issue 1/2023 | 99