Excess free radicals can also be produced by inhaling or ingesting various pollutants, such as those in smoky air and smog—conditions many horses in the Western United States are experiencing right now. | Photo: Tory Kelly/Equine Video Productions

Stress, be it emotional or physical, can negatively affect a horse’s overall health and quality of life. Another type of stress, oxidative stress, also wreaks havoc in horses. Oxidative stress occurs when free radical production and accumulation exceed an animal’s ability to detoxify these highly reactive, unstable molecules. In everyday life, normal metabolic reactions, such as the oxidation of sugar to produce energy, generate free radicals as byproducts.

Excess free radicals can also be produced by inhaling or ingesting various pollutants, such as those in smoky air and smog—conditions many horses in the Western United States are experiencing right now.

Free radicals have unpaired electrons, which are what make them so reactive. Once generated, they bounce around the cell damaging fatty cellular membranes, proteins, and enzymes, as well as