Horse Aging Poem

THE AGE OF A HORSE

To tell the age of any horse

Inspect the lower jaw of course

Six front teeth the tale will tell

And every fear and doubt dispel

Two middle 'nippers' you behold

Before the colt is two weeks old

Before eight weeks two more will come

At eight months the corners cut the gum

The cupping grooves will disappear

From the middle two in just one year

Two years gone from the second pair,

At three years, the "corners" too, are bare

At two the middle incisors drop

At three the second pair can't stop

When four years old the third pair shows

At five, a full new set she shows

The deep black spots will pass from view

At six years from the middle two

The second pair at seven years

At eight the corner spot disappears

From middle nippers upper jaw

By nine the black spots withdraw

The second pair at ten are bright

Eleven finds the corners' light.

At ten, Galvayne's Groove begins
Outside upper nipper, my friends
From the gum the dark line falls
Until twenty, when time itself calls.

As more years pass, wise horsemen know

The oval nippers, three-sided grow.

The aging incisors loosen and spread,
Until that time, which we all dread.

The horse pictured at the top is ~4 years old. At 4½ the lower corner baby nipper will be replaced the permanent incisor. Note the difference in the size of the baby teeth compared to the permanent teeth.

Nippers are the incisors, the grass acquisition teeth. It is the incisors we assess to age the horse.

This is the revised version to "every fear and doubt dispel" Of course, this aging system depends on the horse being examined for age having lived a natural existence, grazing with others most all her life, continuous lifetime foraging as the horse evolved to do. Grazing teeth wear consistently, and aging is quite accurate, for horses raised up here on the Blackfeet Indian Reservation. Some, however, may not let you look them in the mouth. Those horses have to be aged from a distance, and many Blackfeet have quite an eye for that, as well. 

Mind you all, stabled horses' teeth with wear differently than horses offered a natural grazing and socializing existence, especially those stabled horses who are often deprived of forage and locomotion for periods of time. Horses need to move and forage most all the time to maintain health, vigor, and trainability. 
The feeding of artificial grains and the development of stereotypic behaviors due to deprivations of forage, friends, and locomotion alter teeth wear dramatically, as well. 
This goes without saying: 
Horses who graze continuously in natural settings often have healthier teeth and lives than stabled horses. Look all horses in the mouth, please, each and every one, every time, my friends.

Dr Gustafson is an equine veterinarian, veterinary behaviorist, and novelist. He helps refine horse training to accommodate the inherent natures and preferences of horses. Applied veterinary behavior enhances optimum health, performance, soundness, contentment, and longevity in equine athletes. Training and husbandry from the horse's perspective result in content, cooperative horses. DrSid provides equine behavior consultations to help recreate the needs and preferences of stabled horses in training and competition.