Do you think your horse moves a bit unevenly after a trim? You might be right. Researchers recently showed that while routine farriery care had little influence overall on horses' movement, horses do show some movement asymmetry after being trimmed.

Thilo Pfau, PhD, a lecturer in the Royal Veterinary College Department of Clinical Science and Services, presented recent research on the topic at the 2013 International Equine Conference on Laminitis and Diseases of the Foot, held Nov. 1-3 in West Palm Beach, Fla.

"Horses are shod regularly to protect the hooves from excessive wear, keeping the horse sound and able to perform optimally," Pfau said. But it wasn't clear whether the acts of pulling shoes, trimming, and reshoeing themselves affect movement symmetry, a measurement veterinarians use to assess soundness. So Pfau and colleagues set out to evaluate the effects of four stages of routine farriery care on horses' movement symmetry.

The team employed 30 Irish Sport-type horses, ranging in age from 4 to 21, being shod at 2- to 3-week intervals. They evaluated each horse at four stages before and after shoeing: with the old shoes on, after shoe removal, after trimming, and after being reshod and dressed. The team used an inertial gait analysis system that collected data through small sensors attached noninvasively to the horse's poll and croup. The device then transmitted information about the horse's motion symmetry to a laptop computer for the veterinarian to evaluate.

"We use full 6 degrees of freedom sensors that allow us to quantify orientation of the sensors, as well as linear accelerations in three directions," Pfau explained. "We then used this information to calculate true vertical movement of each landmark (sensor)."

Upon reviewing their results, the team found that there were "no significant influences of shoeing stage on head or pelvic movement symmetry." However, Pfau said, the team found significant changes in pelvic measures between the shoeing stages; basically, the horses moved more asymmetrically in the pelvic region after trimming than they did before.

"While, overall, routine farriery had little influence on the amount of movement symmetry, changes between the shoeing stages revealed that in particular before/after trimming, significant differences can be found," Pfau said. "This highlights the importance of investigating the sensitivity and specificity of these changes to detect underlying subclinical lameness."

So should this research impact how you shoe your horses? Maybe not now, but perhaps in the future.

"We did not find any differences between old and new shoes," Pfau said. "However, bear in mind that these horses underwent a 2- to 3-week shoeing cycle. Further studies should investigate this with horses being shod at a 6- to 8-week cycle since trimming (which here had the biggest effect) affects the balance of the hoof. …. This is high up on our list (of research) to do."