CONTACT: Jeffrey S. Douglas, APR 540-231-7911 [email protected]
EQUINE GASTRIC ULCER SYNDROME AFFECTS 80 to 90 PERCENT OF RACEHORSES
BALTIMORE, Md, Dec. 8, 1998--Research presented Monday at the Equine Gastric Ulcer Syndrome (EGUS) in Baltimore confirms that up to 90 percent of performance horses suffer from gastric ulcers, and that intensive training is one of their causes. Ulcers can be painful, impair performance, and in some cases, can cause death.
The symposium was presented through the Virginia-Maryland Regional College of Veterinary Medicine and Virginia Tech's Office of Continuing Education and was held for veterinarians attending the American Association of Equine Practitioners' Annual Convention.
Michael Murray, DVM, MS, Associate Professor and Adelaide C. Riggs Chair in Equine Medicine at the Marion duPont Scott Equine Medical Center in Leesburg, Va., provided a historical review of equine gastric ulcer syndrome (EGUS), which has only recently been widely recognized as a serious health problem in foals and adult horses.
The term Equine Gastric Ulcer Syndrome (EGUS) describes damage to the horse's stomach lining caused by excessive stomach acid or impairment of some of the natural protection of the stomach lining. This acid-induced damage can cause discomfort, which can cause the horse to eat poorly. In some cases, usually in foals, ulceration can be severe enough to cause death.
Clinical signs of EGUS differ in adult horses and foals. Adult horses tend to present with a combination of poor appetite, dullness, attitude changes, decreased performance, poor body condition, rough hair coat, weight loss, or low grade colic. Foals tend to exhibit a combination of intermittent nursing, laying on their backs, poor appetite, intermittent colic, poor body condition, diarrhea, teeth grinding and salivation.
While definitive diagnosis can only be made with endoscopy, the clinical signs and symptoms may form the basis for empiric therapy for ulcers after other disorders have been excluded.
"In horses with recurrent colic, gastric ulceration should be considered as a possible cause, and an endoscopic examination performed to confirm or rule out the possibility," said Murray. "If an ulcer is identified, treatment for gastric ulcer should be initiated."
Currently there is no medication approved by the Federal Drug Administration to treat equine ulcers. Medications used to treat humans have been used with apparent success to treat horses for gastric ulcers.
Gastric ulceration was recognized as a potentially fatal problem in foals as a result of research conducted in the early 1980's, according to Murray. In the mid- and late 1980's sophisticated endoscopes were used to demonstrate that up to 50% of young foals and up to 90% of racehorses developed gastric lesions. Research conducted during this decade has been primarily focused on understanding how equine ulcers occur and developing treatments.
The equine stomach secretes acid continuously and has two different linings, Murray explained. Lesions in the squamous mucosa lining the upper portion of the equine stomach result primarily from excessive acidity, whereas lesions which affect the gastric glandular mucosa lining the bottom of the stomach result primarily from defective mucosal protection, he said.
Risk factors for ulcers include feeding management and eating behavior, training, and illness.
The lifestyle of the performance horse is also a significant risk factor.
Horses evolved as wandering grazers, and their digestive tracts are designed for continuous consumption of forage. As a result, ulcers are infrequent seen in horses maintained solely on pasture. Feeding discreet meals that include high caloric concentrates or extended periods of fasting lead to gastric acid output and inadequate acid neutralization. Grains and pelleted concentrates can increase the production of gastrin, a hormone that stimulates gastric acid production. Hay fed alone affects gastrin production to a lesser degree.
Most performance horses in race training are confined for much of the day and fed large grain meals. Also, they are often fasted for an extended period of time before exercise, allowing gastric acid to accumulate in the stomach and affect the acid-sensitive squamous lining of the stomach. In addition, Murray said, intense exercise itself appears to further contribute to stomach lesions.
The Marion duPont Scott Equine Medical Center is an advanced-care equine referral hospital operated by the Virginia-Maryland Regional College of Veterinary Medicine and owned by Virginia Tech.
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