Volume 21, Number 10, 2001 485

HORSE HEART TESTING SERVICE

Equine veterinarians at North Carolina State University’s College of Veterinary Medicine (NCCVM) are announcing its new non-invasive, pulmonary function testing service. NCCVM’s teaching hospital is one of only two sites in the US able to perform the testing. The testing diagnoses and monitors a horse’s heart and airwaves for obstructions. It is particularly helpful in diagnosing horses with inflammatory airway disease. Without testing, clinical signs of the disease are exercise intolerance and cough. However, testing can uncover airway hyperactivity. The testing can also establish baseline measurements from which to monitor environmental management and anti-inflammatory therapies. Contact: Celeste Brogdon (919) 513-6662

USDA GRANT TO STUDY EQUINE RESPIRATORY DISEASE

The United States Department of Agriculture has awarded two Louisiana State University (LSU) veterinarians a $164,000 grant to investigate endothelin-1. This is a naturally occurring substance in horses and humans; researchers are examining its role in equine recurrent airway obstruction (RAO). The disease is a common equine respiratory condition that causes bronchial constriction, pulmonary inflammation and emphysema in later stages. It is associated with other diseases, often referred to as “heaves,” which is similar to asthma in humans. However, the condition in horses is not as well understood. LSU researchers believe endothelin-1 is produced by a substance that lines blood vessels, tissues and cells. Its function is to constrict and in the lungs this leads to a closing of the horse’s airway passages. While scientists continue to learn more about the condition, the ultimate goal of their research is to discover blocks

to endothelin receptors to allow airways to remain open. Since RAO in horses is similar to asthma in humans, the research serves as a model for studies of the human form of the disease. Contact: Melissa H. Edmonston (225) 578-9922

SOLVING THE LAMINITIS PUZZLE

Auburn University veterinarians in Alabama are looking for genetic patterns that could indicate whether a horse is susceptible to laminitis, a crippling disease sometimes called “founder.” By studying blood cells within the affected foot and screening for genes, researchers hope to determine what occurs 48-72 hours before the animal shows clinical signs of the disease. Once such a determination is made, veterinarians can focus on ways to block specific genes before crippling takes place. Contact: Charles Martin (334) 844-3698

RACETRACK INJURIES

A study, which appeared in the Janu-ary issue of the Journal of the American Veterinary Medical Association, sought to determine the incidence of injuries in racehorses at two Florida racetracks, and to identify risk factors. Of every 1,000 Thoroughbreds who race, one or two receive catastrophic musculoskeletal injuries at the track, and most who do are euthanized.

University of Florida (UF) researchers calculated the incidence of musculoskeletal injuries that occurred for all races held at the two tracks from 1995 to 1998. Race-start characteristics— a variety of factors pertaining to horse, race and track— were compared among 97 Thoroughbreds who were euthanized because of their injuries and 388 horses randomly selected from uninjured participants. For each horse, epidemiological data were collected from official race-day programs and a

computerized commercial racehorse database.

Horses who had gone 33 or more days since their last race were 2.5 times more likely to be hurt than horses who had waited two weeks or less to race again— possibly because horses who waited longer to race were recovering from other health problems, leaving them susceptible to new injuries.

These findings support existing data from California studies showing that sex and days since last race are important factors in determining risk of injury to race horses. UF researchers also found, however, that due to a variety of conditions, horses racing on natural grass turf may stand a greater risk of injury at Florida tracks than their counterparts who are running on dirt.

It’s not just the track surface, but other conditions that are often present in turf races that may predispose horses running in these races to major musculoskeletal injury. Turf races are typically more competitive than dirt races at Florida racetracks. For example, these data show that horses that run on turf are more likely to participate in races with large fields, handicap races, long races and races with high purse values, compared to those running in dirt races.

Dr. Wayne McIlwraith, president of the American Association of Equine Practitioners and director of orthopedic research at Colorado State University in Fort Collins, called the study “an important contribution” but said he was cautious about the researchers’ turf-related finding.

“This study does lay this issue into question, and that is appropriate,” he said. “However, as the researchers themselves pointed out, there are a variety of factors to be considered, including the types of horses that are going to be racing on turf in the first place.”