SPAOD is a life-long disease without a cure, although proper management and medical therapies can minimize its clinical signs. | Photo: iStock

• A: Keep your horse out of the barn and turned out to pasture, or
• B: Keep your horse away from pasture and stabled indoors?

Although this may come as a surprise to owners of horses who show signs of heaves when stalled in the winter barn, the answer is B: Keep your horse inside.

Summertime Blues

Most horse owners—at least, those in the north, Midwest, parts of the west, and the northern tier of southern states—see the onset of RAO in their horses occurring during the winter when their horses spend a lot of time stabled. An inflammatory obstructive airway disorder sometimes referred to as heaves or COPD (chronic obstructive pulmonary disease), RAO-affected horses have an allergic reaction to something in their environment, causing constricted airways and excess mucus production. But where summers are hot and humid, a similar syndrome occurs known as summer pasture-associated obstructive pulmonary disease (SPAOD).

Explains Carla Sommardahl, DVM, PhD, Dipl. ACVIM, assistant professor of large animal medicine at the University of Tennessee’s College of Veterinary Medicine, “SPAOD is a form of recurrent airway obstruction very similar to heaves—but the triggers that cause the hyper-reactions are different