Associate Professor of Medicine Texas Tech University School of Veterinary Medicine Kapaau, HI, United States
Abstract:
Background: Poor air quality has been reported repeatedly in equine facilities; including in stalls, stables, and indoor arenas. A substantial risk factor for the development of asthma in humans is poor air quality (AQ). To date limited information is available on the association between AQ and equine asthma.
Hypothesis: There is an association in horses between poor AQ and the prevalence of specific asthma phenotypes.
Animals: A total of 52 horses in Texas with clinical signs or history consistent with equine asthma were enrolled at four sites.
Methods: This study was a multi-site, cohort study in horses with suspected asthma. Diagnosis of asthma was based on BALF cytology. A DustTrak Aerosol Monitor measured size segregated mass fraction concentrations at the horse’s location. Particulate matter (PM) 2.5 results were converted to air quality index (AQI) measurements for four to five continuous days.
Results: One site had good AQI, and one site had AQI that was moderate to unhealthy for sensitive groups for the evaluation period. Two sites had AQIs in the unhealthy range for three of the evaluation days. A statistical difference by Chi-square analysis for asthma phenotype by AQI was identified; with an overrepresentation of mastocytic asthma at sites with unhealthy AQI. Neutrophilic asthma was only identified at sites with unhealthy AQI.
Conclusion and Clinical Importance: The association between the occurrence of equine asthma and poor air quality is consistent with results found in humans. Veterinarians should provide housing recommendations for asthmatic horses when air quality is poor.
