Equine asthma in Brazil – a scoping review

Abstract

Asthma is a chronic respiratory disease that can occur in horses of different breeds and ages. While its occurrence has been reported in many countries, its occurrence across Brazil is unclear. This review aimed to gather information about equine asthma from studies performed in Brazil by different groups and investigate a variety of horse populations. Articles published in peer-reviewed scientific journals, as well as information contained in dissertations and theses, were searched on PubMed, SciELO, Google Scholar, and the Brazilian government catalog of dissertations and theses. Fifteen studies were included in this review, and according to the published information, the authors identified equine asthma using clinical signs, endoscopic findings, and/or cytological examination of tracheal wash and/or bronchoalveolar lavage fluid. Studies have investigated horses of different breeds and activities (racehorses, police horses, riding horses, Crioulos horses, and others) and were performed in different regions with diverse climatic conditions. On the previous observed studies, the occurrence varied from 14.0% to 60.0%, with a mean occurrence of 24% for severe asthma. Other studies must be performed to further understand the occurrence of equine asthma in Brazil, according to different climatic regions.