Rio de Janeiro

A disease that poses a serious risk to the health of competitors is stirring concern ahead of this year’s Olympics.

But the culprit isn’t Zika, and the athletes aren’t human.

The equestrian world is buzzing about a Brazilian outbreak of glanders disease, a deadly equine respiratory condition, as the sport’s top riders and their mounts prepare to compete in next month’s events in Rio de Janeiro.

Highly contagious and incurable, glanders has prompted Brazilian agricultural officials to destroy hundreds of horses across the country over the past couple of years in an effort to stop the epidemic. That has infuriated some Brazilian breeders who say the threat is overblown.