Impacts of Adiposity on Exercise Performance in Horses

SIMPLE SUMMARY: Increased incidence of obesity in our equine population has clear negative impacts on equine health, such as increasing the risk of equine metabolic syndrome and laminitis. Excessive adipose tissue likely also has negative impacts on exercise performance, due to a combined inflammatory response and the effects of excessive weight carriage on work effort and limb health. This review explores research conducted in these areas. ABSTRACT: There is ample research describing the increased risk of health concerns associated with equine obesity, including insulin dysregulation and laminitis. For athletes, the negative effect of weight carriage is well documented in racing thoroughbreds (i.e., handicapping with weight) and rider weight has been shown to impact the workload of ridden horses and to some degree their gait and movement. In many groups of competitive and athletic horses and ponies, obesity is still relatively common. Therefore, these animals not only are at risk of metabolic disease, but also must perform at a higher workload due to the weight of their adipose tissue. Excess body weight has been documented to affect gait quality, cause heat stress and is expected to hasten the incidence of arthritis development. Meanwhile, many equine event judges appear to favor the look of adiposity in competitive animals. This potentially rewards horses and ponies that are at higher risk of disease and reinforces the owner’s decisions to keep their animals fat. This is a welfare concern for these animals and is of grave concern for the equine industry.