As you untack from your lengthy trail ride, which consisted of several gallops, your mare stretches longingly toward the nearby water trough. You notice she is still hot and breathing hard. Do you let her take a sip, or are you putting her health at risk?

A research group at Michigan State University has been investigating rehydration methods of equine athletes. Hal Schott II, DVM, PhD, Dipl. ACVIM, Assistant Professor of Equine Medicine at the MSU College of Veterinary Medicine, is a principal investigator in the studies.

"The focus has been to look at a strategy to improve the horse's ability to rehydrate after work, and a way to stimulate drinking during breaks in competition," he said.

According to Schott, there is a myth that has been passed on from generation to generation of horsemen probably since the 1600s. The myth claims that if you give hot horses water, ailments will appear as a result. He assures that he has found there is no evidence of colic or founder after giving water to hot horses.

"We're worried that many people give horses just a small drink (after work) for this reason," he adds. "Our hypothesis was that giving them (just) a small drink of water would cause them to drink less in the hour following work."

Investigating that possibility, Schott found that horses given only a small drink when hot did not necessarily curb continued thirst satiation after cooldown. All three study groups-- a group that was allowed to drink until satiation when hot, a group that was offered a small drink, and a group that was not offered water until after cooldown-- had similar total water consumption.

The current research focus is examining rehydration and sodium replacement in the horse. Schott refers to a strategy of training horses to drink salt water, used by the Australian team in the 1996 Atlanta Olympics. "We know that sodium ions stimulate drinking water. The idea is that if thirsty and you drink salt water, the sodium wonât be lowered in the blood (when you sweat)."

We would like to get the horses to drink salt water initially, but follow with regular water. The net effect is better hydration."

Schott explains that the horses do not completely replace the fluid they lose due to dehydration. The horses drink some water, but donât recognize that theyâre still dehydrated. After losing electrolytes and water, only water is replaced.

Electrolyte supplements and Gatorade have been used to some extent to try and replace these lost components in horses.

"We want to find out how we can make horses rehydrate more efficiently without passing a stomach tube down. How can we trick them to rehydrate themselves more?" he asked.

Schott has a group of two-year-old Arabians involved in 45 km treadmill studies. A variety of concentrations of salt solutions will be given at times before work, and before, during, and after cooldown, with some followed by regular water. Schott knows the balance will be delicate, because if the water is too salty, it will not be palatable.

The research ideally will set horse rehydration guidelines for endurance riders and the horse community in general. "All those kind of things (the myths about water) are based on anecdotes. Before we make any recommendations to large groups of people about water, we need to have some solid experimental data which is one, helpful and two, not detrimental."

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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