How Common are Dental Abnormalities in Horses?
Before domestication, horses grazed for 16 to 18 hours a day. Pulling, biting, and chewing a variety of forages naturally maintained their tooth edges and rounded off sharp edges—essentially, it helped keep horses’ teeth healthy.

“Free-roaming horses use their teeth harder and longer when eating fresh grass as compared with a pelleted feed,” explained Teerapol Tum Chinkangsadarn, DVM, a PhD candidate at the University of Queensland School of Veterinary Science, in Australia. “The domestication of horses has limited their grazing time, which has led to an increase in dental diseases or abnormalities.”

To get a better idea of just how prevalent dental abnormalities are in domestic horses, Chinkangsadarn and colleagues examined the skulls of 400 horses, ranging in age from 1 to 30 years, presented to an abattoir (slaughterhouse) in Queensland.

The team determined that horses aged 11 to 15 had the highest occurrence of dental disease and abnormalities. Of those, 59.2% had hooks, 30.8% had wave mouth, and 26.7% had periodontal pockets (severe gum disease).

“These problems could have developed from untreated, small abnormalities such as a retained baby tooth, a misalignment of teeth, or small periodontal (gum) pockets at a young age,” he said. Left untreated and combined with regular rations of processed feeds that don’t encourage proper tooth usage, minor dental issues can manifest into more significant diseases or abnormalities.

To reduce a horse’s chances for developing dental diseases or abnormalities, Chinkangsadarn suggests increasing grazing time and feeding on the ground rather than in elevated feeders. This, he said, encourages the horse to chew more and, thus, increases the jaw’s natural grinding movement.

“We also recommend routine dental examinations by qualified equine dental veterinarians,” he stressed. An annual exam for middle-aged nonworking adult horses is sufficient, while young, working adult, and senior horses should be examined twice a year.

“This routine will prevent the small abnormalities from progressing to more severe (ones) or could pick up some early advanced disease, such as tooth fracture or pulpitis,” a condition in which blood-borne bacteria become lodged within the tooth’s pulp, he concluded.

The study, “An abattoir survey of equine dental abnormalities in Queensland, Australia,” will appear in an upcoming issue of the Australian Veterinary Journal.