Atrial Fibrillation a Heritable Trait in Standardbreds

Researchers found high degrees of heritability (up to 0.17), especially in male horses and in pacers.

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Atrial Fibrillation a Heritable Trait in Standardbreds
The researchers found that hock OC lesions were more common in trotters than pacers (shown here). | Photo: Thinkstock
A healthy heart is an important part of a racehorse’s success. But veterinarians have noted that a form of cardiac arrhythmia, known as atrial fibrillation (AF), appears to be showing up more commonly among Standardbred trotting and pacing horses. And researchers in Canada recently confirmed that this growing trend has a lot to do with genetics—it appears AF has a fairly strong heritability.

“The heritability of atrial fibrillation was found to be quite significant for a disease trait,” said Flavio Schenkel, PhD, of the University of Guelph’s Ontario Veterinary College Department of Animal Biosciences.

“Based on our finding, AF-positive parents will increase the incidence of this disease in the herd and in the population of Standardbred horses as a whole,” he said. “The increase might be initially slow, but will be cumulative and will gain momentum over generations.”

In their study, Schenkel and colleagues examined the racing and health records of more than 1,200 Standardbred racehorses, including more than 200 that had been treated for AF at the Ontario Veterinary College Teaching Hospital. They also analyzed those horses’ pedigrees, which included more than 12,000 animals, to look for genetic links among AF-positive horses

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Passionate about horses and science from the time she was riding her first Shetland Pony in Texas, Christa Lesté-Lasserre writes about scientific research that contributes to a better understanding of all equids. After undergrad studies in science, journalism, and literature, she received a master’s degree in creative writing. Now based in France, she aims to present the most fascinating aspect of equine science: the story it creates. Follow Lesté-Lasserre on Twitter @christalestelas.

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