You’ve probably heard the old adage from mule fanciers: "Mules is just different." Well, it seems that the same principle holds among racehorses; racing Quarter Horses, it seems, are just different. From racing Thoroughbreds, that is. Researchers presented results from their study of racing Quarter Horse injuries and horseshoe toe grabs at the 2009 American Association of Equine Practitioners (AAEP) convention, held Dec. 5-9 in Las Vegas, Nev., revealing that they found very different effects of toe grabs than researchers found in previous research on racing Thoroughbreds.

Catastrophic injuries in horse racing seem to be attracting more attention from media and researchers these days. The increase in research directed toward reducing the incidence and severity of racing injuries is certainly a good thing, and it has resulted in some safety-oriented regulations and recommendations for Thoroughbred racing (such as mandates to use particular track surfaces and shoeing practices deemed safer than others).

While it might be tempting to extend those Thoroughbred flat-racing recommendations to all racehorses, recent research suggests that this might not be advisable. At the AAEP convention, Mark Martinelli, DVM, MS, PhD, Dipl. ACVS, of California Equine Orthopedics in San Marcos, Calif., discussed the results of a study on the relationship between toe grabs on horseshoes and catastrophic injury in racing Quarter Horses.

A toe grab is a raised rim on the toe area of a horseshoe; its purpose is to help the horse "dig in" to the track and reduce slipping (much like football or baseball cleats). However, there are increased stresses on the limbs from this stronger grip on the ground and quicker "stops" of the feet when they land (normally the foot slides forward just a bit on the ground before stopping, but toe grabs arrest this slide). It’s also been suggested that toe graps add stress to the limb by raising the toe relative to the heel. Toe grabs on front feet have been associated with increased incidence of catastrophic injury in Thoroughbreds in at least four studies, reported Martinelli. (Editor’s Note: Research by Sue Stover, DVM, PhD, Dipl. ACVS, of the University of California, Davis, has demonstrated that "high" toe grabs on front shoes make a Thoroughbred 16 times more likely to suffer a catastrophic injury while racing