Potential Effects of Stress on the Performance of Sport Horses

• Factors that make a horse a good sport performer can be influenced by stress.
• Stress can bias the sporting ability of horses.
• Stress responses are affected by the type of sporting activity/discipline.
• Horse temperament and behavior affect stress responses and their sport performance.
• A strategy for breeding of sport horses should include consideration of stress.

Because of its physical and physiological characteristics, the horse has a natural predisposition for use in sport. However, the use of horses as “competition tools” frequently results in several problems related to stress that directly or indirectly bias their sporting performance. Hence, the aim of this manuscript was to examine literature on the influence of stress on sport horse performance and highlight potential avenues for improvements in their breeding and welfare. The stress response is initiated when a stimulus (the stressor) is perceived as a potential threat, resulting in a combination of biological responses designed to alleviate the effects of the perceived stressor. Stress can have positive as well as negative effects on the body helping the animal to cope with routine short-term stressors that in some circumstances can enhance performance, but in others, it can impair performance. A good sport performer has a combination of superior conformation, an appropriate temperament, a healthy physical condition and primed physiological mechanisms, and function for optimal fitness that keeps the horse performing well. In addition, it is more valuable if it has the appropriate genetic background and good reproductive ability. How stress can potentially affect these characteristics is discussed in this review. The development of a broader selection strategy for breeding of sport horses that takes into account aspects as conformation, temperament, genetics, health, and the physiology of the horse, together with an adequate control of the environment, is likely to improve the welfare of horses during competitions.