Pasture Rest May Be the Best Treatment for Stress Remodeling in Racehorses

A problem often seen in young racehorses as they begin heavy race training is stress-related remodeling of the cannon bones (bucked shins). Subjected to more exercise and heavier loading than previously experienced, the bones may develop microstructural pathologies as they attempt to adapt to the demands of training. Small cracks, lameness, arthritis, and fractures can result.

According to a team of veterinarians from Rood & Riddle Equine Hospital, pasture turnout for affected horses can be a better treatment for stress remodeling than stall rest. A study directed by veterinarians Travis Tull and Larry Bramlage studied the records of 55 Thoroughbreds aged two to six years old that were diagnosed with stress remodeling of the lower cannon bone. When these horses were turned out in small pastures for 60 days, lameness and stress remodeling resolved in 44 of the 55 horses. With an additional 30 to 90 days of turnout, the remainder of the horses recovered.

After this treatment, 52 of the 55 horses returned to training and started in at least one race, and 14 horses that had raced before injury were able advance in racing class after the pasture turnout treatment. These results are better than the 40-54% of horses identified in previous studies as returning to their previous levels of work. Horses in those studies were treated by stall confinement and intra-articular and systemic medications rather than pasture rest.