If blooming trees and growing grasses leave you with a runny nose and itchy eyes, you may wonder if horses can suffer from similar seasonal allergies. The answer is “yes” but not nearly as often. Seasonal allergies in horses are rare, but they are more common in geographic regions where people are often affected---grassy, flowery areas, rather than drier landscapes.
In horses, seasonal allergies often cause a runny nose and watery eyes. Allergies are also associated with headshaking, but research shows they aren’t the most common cause of this behavior. Sometimes seasonal allergies cause hives---large, raised welts all over the horse’s body that may or may not be itchy. Hives often indicate contact with an allergen but can also be triggered by something a horse inhales or ingests.
Diagnosing seasonal allergies in horses starts by ruling out other potential causes, such as an infectious disease or reaction to a new shampoo, fly spray or other product. Once that is done, your veterinarian may prescribe antihistamines or, for severe cases, a short course of corticosteroids. Hives can also be treated with a cool bath with mild shampoo.
Seasonal allergies typically go away with the passage of time and changes in the local environment, perhaps even before you can identify the culprit. If your horse develops severe or chronic allergies, your veterinarian may recommend skin testing to narrow down the possible triggers so you can make management changes that reduce a horse’s exposure to the causal agents.
This article first appeared in EQUUS issue #440.