LAUSR

It has long been known that the domestication of horses led to the development of chronic noninfectious small airway diseases. The terminology used to describe these conditions has evolved in parallel with findings related to their clinical, anatomical, histological or functional features. Heaves, equine emphysema, chronic bronchiolitis, equine chronic obstructive pulmonary disease, summer pasture associated obstructive pulmonary disease, lower airway diseases, recurrent airway obstruction and inflammatory airway disease (IAD) have been used either interchangeably or to describe specific manifestations or characteristics of the disease. As new features (functional, anatomical and pathobiological) of these conditions are emerging, the term “equine asthma” has been proposed [1], given its many similarities with human asthma [2]. Driven by the incurable nature of the condition in some horses, and the progression of clinical signs often leading to premature retirement or even euthanasia in its severe form, our research group has focused its attention on the alterations (remodelling) affecting the lower airways and their response to current therapies. We will summarise here recent findings that may change the paradigm dictating the clinical approach to equine asthma in favour of an early recognition of the condition for its prevention, and hopefully, the development of targeted therapies to prevent, or even reverse, established tissue remodelling. Although bronchoalveolar lavage fluid (BALF) cytology remains the cornerstone of the diagnosis of equine asthma, novel diagnostic methods have been developed to assess the remodelling affecting the equine airways and eventually to identify horses predisposed to progress to the severe phenotype.