News Release

Stuart research funds generating dividends for veterinary medicine

Peer-Reviewed Publication

Virginia Tech

Colic remains the leading killer of horses, and though well-studied in recent years, much about the disorder remains enigmatic.

Colic involves blockages or twists of the horse’s gut, according to Nathaniel White, the Theodora Ayer Randolph Professor of Equine Surgery at the Marion duPont Scott Equine Medical Center in Leesburg, Va.

When a horse has colic, veterinarians generally administer analgesics to relieve intestinal discomfort and laxatives like mineral oil to help eliminate the blockage. Some horses require surgery, and about six to seven percent of horses that have colic will die.

But thanks to research funded by grants to Virginia Tech from the estate of the late Patricia Stuart, researchers at the Marion duPont Scott Equine Medical Center are making some important discoveries about what causes colic and finding better ways to treat it.

Researchers know that hydration of the horse and its intestine is related to colic, and that hydration can be affected by diet. But in a significant finding supported by the Stuart funding, White and colleagues have determined that dietary grain affects colonic hydration.

“When you switch feeding from hay only to hay and grain, water content decreases significantly,” said White, who is regarded as one of the profession’s leading colic researchers. “These are significant changes that we believe are important to gut function. I consider this to be a major finding.”

White believes that when grain replaces the forage amount, dietary fiber is reduced and because water binds to fiber water in the colon is decreased when feeding grain.

“This work is resetting the stage for what will be the next step in finding the relationship between diet and colic,” he added.

In a related part of the work, researchers determined that the most effective laxative for increasing the water content of the colon is the rapid oral administration of an electrolyte solution which is similar to the electrolyte concentrations in blood.

Compared to other laxatives such as magnesium sulfate or sodium chloride, the balanced electrolyte solution does not affect the horse’s electrolyte balance while hydrating the colon contents.

In another project undertaken with Stuart funding, researchers discovered that colic is associated with certain molecular characteristics of cellular death.

Scientists know that cells die in two ways. Apoptosis is the term that describes how cells are pre-programmed to die. These cells die “naturally” as part of normal growth processes. Necrosis is cellular death through disease or trauma.

Working with White, Ph.D student and surgical resident Emma Rowe determined that apoptosis was occurring in intestine of horses with colic.

The researchers noted that during a strangulation event that caused some tissue ischemia, cells released cytokines that stimulate inflammation. These cytokines also turn on a cascade of enzymes in the nucleus of cells that induce apoptosis.

“If we can figure out a way to stop apoptosis, we can reduce the morbidity from colic,” said White. “This opens up a whole new area to study in horses with colic.”

The work was reported at the American College of Veterinary Surgeons’ Annual ACVS Symposium and the international Equine Colic Research Symposium put on by the British Equine Veterinary Medical Association.

Future work will look at ways to inhibit the cellular events that lead to apoptosis, White said.

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Funding for the work has come from a $2.7 million bequest left to Virginia Tech by the late Mrs. Patricia Bonsall Stuart, who died in 1996. The gift was divided equally between the Virginia-Maryland Regional College of Veterinary Medicine and the Virginia Tech College of Agriculture and Life Sciences. The Marion duPont Scott Equine Medical Center is part of the Virginia-Maryland Regional College of Veterinary Medicine, which is jointly operated by Virginia Tech in Blacksburg and the University of Maryland at College Park.

Pat and her husband Herbert, who died earlier, were avid horse-people and breeders of Arabian horses. They owned and operated a 200-acre farm near Batesville in Albemarle County. She was active in the Virginia Horse Council and the American Horse Council.

PR Contact: Jeffrey Douglas, jdouglas@vt.edu, 540-231-7911


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