New research published in PLOS ONE has highlighted how the transition from winter to spring can significantly affect the airways of horses with equine asthma, offering new insight into why symptoms often worsen at this time of year.
The study analysed 230 airway fluid samples from horses, comparing healthy individuals with those affected by mild to moderate and severe equine asthma. Using metabolomics, researchers examined small molecules involved in key biological processes within the lungs.
The findings showed clear seasonal effects in asthmatic horses, particularly during the shift from winter to spring. In contrast, horses without signs of asthma showed only minor or non-significant changes.
Several metabolites linked to energy metabolism, including lactic acid and pyruvic acid, were altered in asthmatic horses, suggesting increased metabolic demand in the airways. At the same time, changes in compounds such as valine, taurine and carnitine point towards a role for oxidative stress and inflammation.
The impact was most pronounced in horses with severe equine asthma, where additional biological pathways, including mTOR signalling, were affected. This pathway has been linked in human medicine to airway inflammation and structural changes.
Interestingly, some metabolic pathways, such as cholesterol metabolism, were influenced by season in all horses, indicating a broader environmental effect. However, the response in asthmatic horses was more marked, suggesting they are less able to adapt to seasonal challenges.
The authors suggest that environmental factors associated with spring, such as increased pollen, dust, temperature changes and management differences, may contribute to these shifts. The findings support previous observations that spring is a higher-risk period for respiratory issues.
While the study does not directly assess clinical outcomes, it reinforces the importance of seasonal management in horses with asthma. Understanding how the airway environment changes at a molecular level could help guide prevention strategies and improve long-term management.
Overall, the research provides further evidence that the transition into spring is not just a management challenge, but a biologically significant period for horses with equine asthma.
Read the full Research Article – The transition from winter to spring has an impact on the airway metabolome profile of asthmatic horses
