Keeping a foal in a stall around-the-clock might keep his coat shiny and his body free of nicks and bumps from roughhousing with peers in the pasture, but in the long run, that could cause him serious problems as an active adult. P. René van Weeren, DVM, PhD, Dipl. ECVS, of Utrecht University in the Netherlands, and his colleagues have determined that pasture turnout for a foal in its first year has the most beneficial effect on the four major parts of the musculoskeletal system–cartilage, tendons and ligaments, muscle, and bone. He also determined that even tissues deemed difficult to repair, such as tendons and articular cartilage, are sensitive to remodeling in this age group.

“Rest is very bad for foals. Watch this, because if not, you may end up with a healthy (looking) foal, but one of inferior quality,” warned van Weeren.

He looked at Dutch Warmblood foals in groups that were kept on complete stall rest, given stall rest but excercised daily, and kept completely on pasture exercise. Some were analyzed at five months, and the remaining continued on to 11 months of study.

He and his colleagues found that there is dynamic and rapid development and remodeling of the musculoskeletal system during the period from birth to five months. These changes still occur during the period from five to 11 months, but much more slowly, and some parts such as articular cartilage collagen already have completed forming.

Withholding of exercise led to a retardation of development in the foals. Foals on complete pasture exercise had the highest glycosamioglycan (GAG) content in articular cartilage and tendons (GAGs form the structural pattern and contribute elacticity). Foals which were kept in a box stall, then forced to exercise, had a higher bone density. Tissue quality of the exercised horses was found to be inadequate at 11 months, so heavy exercise in addition to stall rest is detrimental. “To