Strenuous exercise is associated in horses, humans, and dogs with the development of gastrointestinal disease, including diarrhea, cramping, and ulceration. Human marathon runners have up to an 80% prevalence of gastrointestinal bleeding, and racing sled dogs have recently been found to have a 50% prevalence of subclinical gastric ulcers.
Vet checking horse gut health
Strenuous exercise is associated in horses, humans, and dogs with the development of gastrointestinal disease, including diarrhea, cramping, and ulceration.
In severe cases, these subclinical gastric ulcers can be exercise limiting or even life threatening. The goals of current studies are to determine the mechanisms by which exercise leads to gastrointestinal disease and develop methods to prevent such disease.
The Center for Veterinary Health Sciences at Oklahoma State University is currently involved in research related to the development of these gastrointestinal diseases in horses.
According to the Merck Veterinary Manual, prolonged exercise lasting many hours, generates heat that imposes a thermoregulatory demand on a horse. Responses include sweating and/or panting to remove heat from the body. The result is dehydration and acid-base and electrolyte disturbances. These factors are usually implicated in the fatigue, exhaustion, and even the possibility of shock and death that can occur after such exercise in horses.
Fatigue during prolonged exercise has also been associated with depletion of muscle and liver glycogen stores and hypoglycemia. Studies of fatigue during prolonged exercise are difficult in horses, because horses will continue to perform treadmill exercise in the presence of severe, life-threatening hyperthermia and dehydration.
Although a few clinical gastrointestinal syndromes have been associated with exercise in horses and include exhaustion shock syndrome (colitis X) and gastric ulceration, other effects on the gastrointestinal tract are difficult to demonstrate, because of the inaccessibility of much of the equine GI tract and the lack of specificity and/or sensitivity of hematologic analytical tools.
More research is needed to determine the full effects of exercise on gastrointestinal diseases in horses and how to prevent such diseases.