Question: My daughter’s horse was recently diagnosed with pasture heaves. It took a long time to figure out. We were keeping him outside all the time—thinking the fresh air would do him good. But he only got worse. In the autumn and winter his breathing is fine, indoors and outdoors. The veterinarian explained that this horse is sensitive to mold and pollen so he should be kept in all summer. That seems like it could cause other problems. Are there medications make summer turnout an option? Would a dry lot be better than pasture?
Jamie Pribyl, DVM, Professional Services Veterinarian at Boehringer Ingelheim, responds: Summer pasture-associated equine asthma typically affects horses during hot, humid weather. It’s commonly seen in subtropical states, like Mississippi and Florida, but can occur in other areas with similar weather conditions. Although the exact triggers for this condition are not fully understood, pollen and fungi are likely culprits.
Environmental management
Regardless of the cause, environmental management is crucial in treating equine asthma. The primary focus is on removing as many triggers as possible. Although horses with barn dust-associated asthma tend to fare better outside, those with pasture-associated equine asthma typically benefit from being kept indoors during the summer. In fact, some may even require a climate-controlled environment. Of course, when horses are kept indoors, minimizing dust from bedding, feed and other sources is essential. Putting a horse with pasture-associated heaves on a dry lot may not be sufficient due to the likelihood of exposure to pollen and other airborne particles from nearby fields, wooded areas and pastures.
Winter turnout
During periods of remission, usually during the winter months, horses with pasture-associated equine asthma can be turned out. Individual horses may be affected differently by certain types of grasses at specific times of the year. Ideally, owners will monitor their horses to connect the onset of clinical signs to a specific part of the season, and perhaps the growth/bloom of specific trees/grasses. Once triggers are identified, steps can he taken to reduce exposure to them. This can include temporarily removing the horse from the pasture. Relocating horses with asthma to northern states can also be beneficial but this is not an option for most owners.
Medications can help
In addition to managing a horse’s environment, medications like glucocorticoids are often necessary to reduce inflammation affecting the respiratory tract. Glucocorticoids can be administered orally, by injection, or inhalation with a new FDA-approved ciclesonide inhalation spray for severe equine asthma. Bronchodilators may also be used to help relax the smooth muscles surrounding the airways. However, environmental management remains vital. Without reducing a horse’s exposure to triggers, medications may have limited effects, and signs may return when treatment is discontinued.
All in all, by addressing triggers and employing appropriate medical interventions, owners can improve the health and well-being of horses with equine asthma.
Our Expert
Jamie Pribyl, DVM, received her undergraduate degree from Lake Superior State University. She earned her veterinary degrees from the University of Minnesota. Pribyl became a partner at Buffalo Equine in Buffalo, Minnesota in 2008. She practiced there for 13 years, before joining Boehringer Ingelheim in early 2020.
To read more about managing a horse with heaves, read about that research into the benefits of soaking hay by clicking here.
