In this episode of the Disease Du Jour podcast, Katie Sheats, DVM, PhD, DACVIM, discussed the effects of wildfire smoke exposure on horses’ airways. She explained the different types of smoke exposure, treatment and management strategies for exposed horses, and more.
This episode of Disease Du Jour is brought to you by Bimeda.
Types of Smoke Exposure
Sheats explained that there are two main categories of smoke exposure. Direct exposure occurs when horses experience a barn fire or close-proximity wildfire. This type of exposure requires immediate veterinary attention due to the risk of thermal burn and chemical injury to the horse’s upper airway.
Short-term indirect exposure occurs when the air quality is impacted by remote wildfires. There are five major pollutants involved: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Sheats said particulate matter has the biggest impact on respiratory health.
“One of the simplest things for veterinarians to tell their owners is that if you’re feeling the effects of poor air quality, your horse is too,” Sheats said. More specifically, veterinarians can tailor exercise recommendations based on the air quality index (AQI). If the AQI is less than 50, any horse (and human) should be able to exercise safely outside. If the AQI is between 50-100, outdoor exercise should be acceptable, but horses with preexisting respiratory conditions might struggle. An AQI above 100 starts to cause concern for horses and humans, and an AQI above 151 is considered unhealthy for the general population.
Clinical Signs of Smoke Exposure in Horses
Sheats said clinical signs of short-term indirect smoke exposure in horses tend to lag. “You might not notice any signs or changes in your horse until 24-48 hours after that first day of worsening air quality,” she explained. At that point, horses might demonstrate an increased respiratory rate or effort at rest. Horses might also develop a cough or nasal discharge.
“It’s important to realize that the irritation in the airway caused by smoke exposure events is compounded by things in the horse’s environment like dust,” Sheats said. “You may not appreciate a change in respiratory rate, but a horse that didn’t use to cough at feeding time might start coughing.”
Management Strategies for Horses Exposed to Wildfire Smoke
Sheats said proper management is key for horses experiencing short-term indirect wildfire smoke exposure. Management recommendations are similar to those for asthmatic horses. Owners should minimize dust in the horse’s feed, such as by steaming the hay or providing a complete feed or haylage. It’s also important for horses to have access to fresh water at all times. Owners should limit the horse’s exercise during poor air quality days.
Sheats said omega-3 supplementation is also beneficial for horses’ respiratory health. Another treatment being actively studied is saline nebulization. In acute situations or for horses with asthma, steroids can help reduce inflammation in the lungs.
About Dr. Katie Sheats
Katie Sheats, DVM, PhD, DACVIM, is an associate professor of equine primary care at North Carolina State University College of Veterinary Medicine. She completed her DVM, internship, large animal medicine residency, and PhD in comparative biomedical science at NCSU and is board-certified in large animal internal medicine. Her research focuses on neutrophil-mediated diseases that affect horses and humans, including asthma. Sheats is a native North Carolinian and grew up riding and showing hunter jumpers in the Triad region. She now lives in New Hill, North Carolina, with her husband, two boys, 10 chickens, and two retired pleasure horses.
Related Reading
- Ambient Air Pollution’s Effects on Racehorse Performance
- Disease Du Jour: Equine Asthma and EIPH
- Wildfire Smoke Guidelines for Horses
Stay in the know! Sign up for EquiManagement’s FREE weekly newsletters to get the latest equine research, disease alerts, and vet practice updates delivered straight to your inbox.
