Contribution of lung function tests to the staging of severe equine asthma syndrome in the field

Abstract

Staging methods are useful tools for monitoring disease and response to treatment, and because Severe Equine Asthma Syndrome (SEAS) has a high prevalence in the equine population, a clinical staging method can provide important information to optimize equine care. Our team has previously developed and published a clinical staging method for SEAS and in the present study we further evaluated information provided by lung function tests, in order to determine their contribution to disease staging. Using discriminant analysis we set out to produce a new staging method with applicability in the field. Differences between group means (P < .05) were observed for clinical score, bronchoalveolar lavage fluid neutrophil percentage, pleural pressure (ΔPpl), PaO₂ and histamine concentration and the linear functions obtained explained 99.3% of the data variability, with 94.7% of cases grouped correctly and a cross-validation of 86.8%. Thus this staging model showed very good results and the discriminant linear functions may be used to identify and stage SEAS. This method can be used in the field and also in diagnostic and research centres.

Keywords: Diagnosis; Discriminant power; Disease staging; Lung function tests; Severe equine asthma syndrome.