Inflammatory airway disease (IAD) in horses is similar to asthma in humans. In both cases, inflammation in the lungs leads to poor respiratory function and can limit an affected individual’s ability to perform aerobic activities. Researchers know that, in humans, rhinoviruses are responsible for the common cold and can also trigger asthma development. Veterinarians and researchers have long suspected a connection between an equine respiratory pathogen—rhinitis virus—and IAD development, but this theory remains just that—a theory.

So, researchers recently set out to get a better idea of whether rhinitis virus could, in fact, play a role in IAD development.

“Rhinitis virus and the role it plays in the development of equine disease has taken a backseat to more dramatic viral infections like influenza and rhinopneumonitis, (the latter of which is) caused by equine herpesvirus (EHV)-4 and -1,” explained Melissa Mazan, DVM, Dipl. ACVIM, Large Animal Section Head at Tufts University’s Cummings School Of Veterinary Medicine, in North Grafton, Massachusetts.

These more severe respiratory viruses can keep a horse laid up for weeks with respiratory signs, fever, and muscle aches, Mazan said. Equine rhinitis virus clinical signs, on the other hand, are less severe and more similar to the common cold in humans