“Equine Asthma: Such a Heave-y Burden to Bare”

Written by University of Florida veterinary student, Kylie Tank

The later summer and fall will be here before you know it. In Florida, this means that many horses will soon experience what is commonly known as “heaves”. This condition has many names including recurrent airway obstruction (RAO), COPD, broken wind, and emphysema but are all essentially names for the same disease. Equine asthma is an allergic respiratory disease that presents similar to asthma in people. The average age of onset in horses is 9 years and approximately 12% of older horses suffer from some degree of lower airway inflammation induced by allergens like pollen or dusty hay. All breeds of horses are susceptible to this disease and while it is still unclear, an inherited component to this disease process is suspected.

Equine Asthma is a lifelong, progressive disease that requires ongoing management to help maintain a good quality of life for the horse. The classic clinical sign for equine asthma is a persistent, chronic cough. This cough can range from mild to severe and is usually exacerbated with exercise. In the more severe forms, the horse will have wheezing, nasal discharge, and even difficulty breathing. In the more advanced stages of disease, “heave lines” become more pronounced. This is a line that follows along the lower half of the horse’s chest, just below its ribs. Diagnosis is made based on a number of factors such as history, physical examination, and in some cases ultrasound and/or bloodwork in order to distinguish equine asthma from other diseases such as pneumonia.

The most important treatment for equine asthma is environmental management. Round bale hay is the most common cause of worsening asthma for horses on pasture. Complete commercial feeds can eliminate the need for roughage, but hay cubes/pellets can be great alternatives for horses with asthma. Soaking hay in water may also help to reduce clinical signs in horses affected. Medical treatment for equine asthma includes corticosteroids (inhaled or systemic) and/or aerosolized bronchodilators. Despite having RAO, horses with this condition can live relatively normal lives if well-managed and perform tasks such as trail riding, pleasure, and even competitions.