Equine asthma is a serious respiratory disease in horses, similar in some respects to asthma in humans. It can seriously affect a horse’s quality of life and usability. Early recognition of symptoms can lead to halting or slowing the progression of the disease. In this article, we will examine the symptoms of asthma in horses. This article aims to provide information to horse owners so that they can recognize worrisome symptoms and react more quickly.

Equine asthma includes two main categories: mild to moderate equine asthma and severe equine asthma (formerly known as RAO and COPD). These conditions are characterized by non-septic inflammation of the lower respiratory tract, and environmental factors play a significant role in their development.

A study in Brazil found the prevalence of asthma in horses ranged from 14% to 60%, with an average prevalence of severe asthma of 24% (Oliveira et al., 2022). Environmental challenges, particularly organic dust in the stable, play an important role in the development of this disease (Couetil et al., 2020).

What are the symptoms of asthma in horses?

Asthma in horses can manifest itself in different ways, depending on the severity and characteristics of the horse. Typical symptoms include:

Cough: often the first symptom noticed by owners. A horse may cough repeatedly, especially during or after exercise or when in contact with dust and particulate matter, which often increases when hay is fed.

Increased respiratory rate: Watch for increased respiratory effort, especially after activity.

Nasal discharge: Initially the discharge may be clear, but as the disease progresses it may become mucous or purulent.

Reduced performance: Horses with asthma may seem less willing to participate in activities they previously enjoyed, showing signs of fatigue or reluctance.

Loud breathing: wheezing or other abnormal breathing sounds may be heard, especially during exercise.

Distended nostrils: Indicating increased effort to breathe, the nostrils may dilate to take in more air.

These symptoms, while indicative of asthma, can also be signs of other respiratory diseases. It is important to consult your veterinarian for an accurate diagnosis and appropriate treatment plan. If the diagnosis indicates asthma then regular consultations with your veterinarian will help tailor appropriate treatment and limit further progression of the disease ensuring your horse’s well-being despite the challenges of asthma.

Couetil, L., Cardwell, J. M., Leguillette, R., Mazan, M., Richard, E., Bienzle, D., Bullone, M., Gerber, V., Ivester, K., Lavoie, J.-P., Martin, J., Moran, G., Bear, A., Pusterla, N., & Swiderski, C. (2020). Equine Asthma: Current Understanding and Future Directions. Frontiers in Veterinary Science, 7, 450. https://doi.org/10.3389/fvets.2020.00450

Oliveira, T. M., Junior, P. V. M., Fernandes, W. R., & Calomeno, S. S. (2022). Equine asthma in Brazil – a scoping review. Research, Society and Development, 11(8), Article 8. https://doi.org/10.33448/rsd-v11i8.30824