Exploring Stem Cells for Managing Equine Asthma

Does the mere mention of stem cells make your mind jump to tendon and ligament repair? Considering these soft tissues were among the first targets of stem cell therapy in horses, this is a reasonable leap. As advances in regenerative medicine move swiftly, veterinarians now have the power to explore the use of stem cells under vast and varied conditions, including patients with inflammatory conditions such as equine asthma syndrome.

Scientists first thought stem cells either turned into particular cell types or behaved like specific cells inside the patient’s body. For example, if stem cells were injected into a tendon lesion, those cells were believed to become tenocytes (tendon cells) to facilitate healing. Later, researchers learned that stem cells do not need to differentiate into the target tissue cells to be effective. Rather, stem cells secreted soluble factors to promote repair and growth, and to exert anti-inflammatory effects.

Veterinarians from Marion DuPont Scott Equine Medical Center in Virginia recently published an article that describes using stem cells for their anti-inflammatory properties to treat equine asthma, a chronic condition associated with prolonged, low-level inflammation.^*

Although studies involving live horses have not currently been conducted, research in other animals and in laboratory settings suggest that stem cell administration to asthmatics can:

• Decrease the presence of inflammatory cells in the bronchoalveolar fluid (BALF);
• Minimize airway remodeling; and
• Reduce levels of inflammatory mediators, such as interleukin-5, -13, interferon-ã, and immunoglobulin E.

The researchers concluded, “While stem cells may be beneficial in the treatment of asthma based on our animal models, the timing of their administration may play a role in response to treatment. The number of doses and follow-up treatment needs to be investigated.”

Further research would clearly be advantageous considering no cure for equine asthma currently exists. In the meantime, the most up-to-date published treatment guidelines for equine asthma relay that horses can most successfully be managed using a combination of corticosteroids, bronchodilators, and omega-3 fatty acids.

“Kentucky Equine Research recommends the use of omega-3 fatty acids DHA and EPA for respiratory health in horses. In addition to management strategies, such as hay-soaking and extensive turn out, owners are encouraged to use EO-3 in horses diagnosed with equine asthma,” stated Catherine Whitehouse, M.S., a nutrition advisor for Kentucky Equine Research.

 ^*MacDonald, E.S., and J.G. Barrett. 2020. The potential of mesenchymal stem cells to treat systemic inflammation in horses. Frontiers in Veterinary Science 6:507.