Link Between Equine Asthma and Microbiome Explored

Research efforts focusing on equine asthma syndrome have led to strategies that minimize acute respiratory distress and maximize athletic output and quality of life.

Specific recommendations for helping asthmatic horses breathe easier include:

• Maintaining horses outdoors on pasture instead of in stalls to reduce exposure to dust, mold, fungi, mites, endotoxin, and ammonia, all of which can provoke airway inflammation;
• Steaming/soaking hay, using low-dust feeds, and avoiding low-quality round-baled hay;
• Administering corticosteroids (inhaled or systemic) or bronchodilators under the guidance of a veterinarian; and
• Offering omega-3 fatty acids to facilitate the management of equine asthma, such as Kentucky Equine Research’s EO-3 containing DHA and EPA.

“While these are useful suggestions for managing equine asthma, many questions regarding factors contributing to the development of asthma remain unanswered,” noted Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research. “Interestingly, the intestinal microbiome could play a role in asthma, as the microbiome contributes to immune status.”

To learn more about the link between the gastrointestinal and respiratory systems of asthmatic horses, Canadian researchers^* analyzed the microbiomes from asthmatic and healthy horses. Horses were maintained together in one of three environments: (1) on pasture, (2) stabled with access to good-quality hay, and (3) stabled with access to poor-quality hay.

In the case of asthmatic horses, the researchers found that the intestinal microbiota did not adapt in the same way to changes in diet and environment as the microbiota of healthy horses during the study period. A healthy microbiome is diverse, with the type and number of hindgut microorganisms fluctuating in response to diet, stress, or other environmental factors.

“The exact relationship between asthma and the intestinal microbiome remains unclear, especially in terms of inflammatory changes. This area of research certainly warrants further consideration, though,” concluded Crandell.

Rely on products like EquiShure to promote a healthy hindgut. This time-released hindgut buffer helps maintain an appropriate pH and therefore stable microbial populations in the large intestine.

*Leclere, M., and M.C. Costa. 2020. Fecal microbiota in horses with asthma. Journal of Veterinary Internal Medicine 34:996-1006.