How can you tell if that horse you're examining is in his prime or over the hill? You could try pinching his skin, as Arab horsemen did. You could feel his jawbone, judge the distance between his ribs or look for a hollow above each eye. The body equine reveals its age in many ways: An older horse's skin is less pliable and "drier" than that of a younger horse, his jawbone is thinner and sharper, his ribs are spaced farther apart and his eyes sit deeper in their sockets. But none of these "tests" offers anything approaching the reliability of the one you're most likely to use: aging a horse by the appearance of his front teeth. Only registration papers recording the actual birth year provide a more consistently accurate indicator of a horse's age. Still, that doesn't mean that teeth are always truthful.
The method itself is ancient. Chinese drawings from as early as 700 B.C. show men looking in horses' mouths to determine the animals' ages. Common parlance still makes reference to the custom: Everyone knows it's impolite to "look a gift horse in the mouth." The practice dates back to a 19th-century Australian horse trainer and master of self-promotion, Sydney Galvayne, whose name is still associated with a telltale groove that appears on older horses' teeth. Illustrations of age-related changes in equine incisors based on Galvayne's system continue to appear in veterinary and horse-care texts. Only recently has research revealed that this technique--like any other long-held belief--has its exceptions and limitations.
Within the past four years, studies of age-related dental changes carried out in Britain and Belgium have confirmed what many suspected: Teeth do lie about age. One study demonstrated that even professionals who frequently examine horses' mouths can make honest mistakes in judging age based on the shape, coloration and configuration of the upper and lower incisors. In some cases, the experts were off by as much as seven or eight years. Other studies linked exceptions to the usual rules of dentition with breed and individual variations, or with diet and management practices.
In most horse-related transactions, age matters: A 12-year-old is a better investment as a broodmare than a 20-year-old; a four-year-old with lumpy ankles may have a shorter athletic life than a 10-year-old with similar enlargements; a two-year-old often requires different handling than a three-year-old; a selling price that's right on the mark for a seven-year-old is out of the ballpark for a 17-year-old. When legitimate documentation of a horse's birth date settles the critical question of age once and for all, the condition of his incisors is purely a matter of health care and management. But for the hordes of unregistered or otherwise paperless horses, and for the small number of horses offered or represented fraudulently, dentition remains an indispensable--though somewhat flawed--tool in establishing age. So the next time you find yourself looking a horse in the mouth to determine his age, be cautious before you pronounce him young and robust or elderly and infirm. You could be reading the indicators absolutely accurately--or, like the experts in the studies, you could be fooled by the testimony of the teeth.
Several British publications in the 19th century, including one as early as 1818, dealt with the subject of aging horses by their teeth. But it wasn't until Sydney Galvayne traveled throughout Europe in the 1880s, making a living by aging horses at sales and selling his secret to others, that the practice gained wide currency.
Galvayne claimed that he could tell the exact age of any horse brought to him. His book, Horse Dentition: Showing How to Tell Exactly the Age of a Horse up to Thirty Years, published in Glasgow around 1885, cites his numerous triumphs in the face of public skepticism. This account of a demonstration at a London riding school is typical:
The next animal was a bay mare. "Thirteen years," said I.
"Correct," said the owner, "but how do you do it?"
"You pay my fee, and you will know all about it," was my reply.
They then produced a gray. "Three years older than the last one," I quietly observed. "Sixteen years old."
"Right again, but how the deuce do you do it?" was the owner's remark.
I replied, "It's quite easy when you know how."
Galvayne's confident explication of age-linked changes in equine dentition and his claim of infallibility for his method caused considerable anxiety among crooked horse dealers. These shady characters soon developed fraudulent means for outwitting buyers who had read Galvayne's treatise. One such deception, called "bishoping" (after a well-known practitioner of the art), involved drilling new cups in aged incisors, then burning or dying these artificial infundibulums to resemble the dark cups found in more youthful mouths. At the other extreme, a too-young horse might have his baby teeth pulled to make him look six months to a year older.