Shin soreness, or bucked shins, in Thoroughbred racehorses is a partly preventable condition according to a recent Australian study. Horses with shin soreness display signs of pain on the front of the shins between the knee and fetlock, said David Evans, BVSc, PhD, associate professor of veterinary science at the University of Sydney and one of the researchers on the study. "The horse might show signs of lameness during trotting, or have a 'choppy' short stride during galloping."
The study results were presented at the 2005 Australian Veterinary Association meeting in Queensland, held May 15-20.
Evans reported that shin soreness affected 43% of 2- and 3-year-old Thoroughbreds in race training, and 40% of those cases recur. The study found that particular training methods were major risk factors for the condition:
- The risk of shin soreness was increased if the average weekly distance trained was at speeds greater than 890 meters per minute (m/min), or about 33 miles per hour, during the first ten weeks of training. "A gradual increase in the weekly distances at these speeds is the key to reducing the number of cases," said Evans.
- Training at gallop speeds of 800-890 m/min did not increase the risk of shin soreness in a subsequent period of training (training after the horse had a period of rest, a common practice in Australian racing where Thoroughbreds train for several weeks and then rest for a few weeks).
- Judicious use of short gallops (such as 200-300 meters) at speeds greater than 890 m/min can reduce the likelihood of shin soreness in a subsequent period of training once the horse is fit to work at that speed.
- Training horses in order to cause shin soreness does not reduce the risk of the disease in subsequent training periods. (Training tradition has dictated that causing a horse to buck his shins will make his legs more tolerant to future stress and less likely to have the condition occur in the future.) "The practice could increase the risk of other musculoskeletal injuries, and is not in the interest of horse welfare," cautioned Evans.
- Shin soreness occurred less in horses that were older at the start of training (average age of 30 months, compared to horses averaging 28 months of age). Beginning race training at a younger age might put horses at a greater risk for shin soreness.
Evans said there is still more research to be done to create a training program that would eliminate shin soreness in horses. "We are currently doing more statistics on the database to describe the training programs that increase the risk of shin soreness, and training programs that decrease the risk," he said.
For more information on bucked shins, see www.thehorse.com/ViewArticle.aspx?ID=4066.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.