Exercise-induced airflow changes in horses with asthma measured by electrical impedance tomography.
Authors: Herteman Nicolas, Mosing Martina, Waldmann Andreas D, Gerber Vinzenz, Schoster Angelika
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary: Exercise-induced airflow changes in horses with asthma measured by electrical impedance tomography Equine asthma manifests as progressive airflow obstruction during exercise, yet non-invasive assessment tools that capture these dynamic changes remain limited in clinical practice. Herteman and colleagues used electrical impedance tomography (EIT)—a radiation-free imaging technique that measures regional ventilation via impedance changes across the thorax—to quantify peak inspiratory and expiratory flows in nine healthy horses, nine with mild-to-moderate asthma (MEA), and five with severe asthma (SEA) before and after 15 minutes of lunging. Control horses demonstrated significantly reduced global peak expiratory flow (PEF) and peak inspiratory flow (PIF) post-exercise compared to both SEA and MEA groups (mean differences of 0.0859 and 0.0726 arbitrary units respectively, P<0.001 and P=0.001), with similar though slightly smaller differences between healthy and MEA horses (P=0.007 and P=0.002). Notably, flow variables showed no significant differences at rest, suggesting EIT's utility lies primarily in detecting asthma-related impairment during or immediately after exercise when pathophysiological changes become apparent. Whilst the small cohort limits comparisons between MEA and SEA groups, these findings support EIT as a promising objective tool for clinicians seeking to grade airway disease severity and potentially monitor therapeutic response, though further validation studies are needed before widespread adoption in equine practice.
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Practical Takeaways
- •EIT can detect airflow changes in asthmatic horses during or after exercise when resting measurements may appear normal, potentially improving early detection of equine asthma
- •Exercise-induced airflow impairment is evident in both mild-to-moderate and severe asthma cases, suggesting exercise testing may be necessary to distinguish asthmatic horses from healthy ones
- •This non-invasive imaging technique could become a useful diagnostic tool for evaluating respiratory disease in performance horses, though further validation is needed
Key Findings
- •EIT-derived peak inspiratory and expiratory flows differed significantly between healthy horses and horses with SEA or MEA after exercise, but not before exercise
- •Control horses after exercise had significantly lower global PEF (0.0859 AU, P<0.001) and PIF (0.0726 AU, P=0.001) compared to horses with SEA
- •Control horses after exercise had significantly lower global PEF (0.0561 AU, P=0.007) and PIF (0.0587 AU, P=0.002) compared to horses with MEA
- •No significant differences detected between mild-to-moderate and severe equine asthma groups