Van Erck and her team found that horses had a higher likelihood of fungi in their airways if they were bedded on straw vs. shavings. | Photo: Anne M. Eberhardt/The Horse

We know the ubiquitous dust and pollen present in horses’ forage and bedding can trigger equine asthma and respiratory allergies. What about fungi, though—how prevalent is it in horses’ environments, and could it be contributing to inflammatory airway disease (IAD)?

Emmanuelle van Erck, DVM, PhD, Dipl. EBVS, ECEIM, and her team at Equine Sports Medicine Practice in Waterloo, Belgium, sought to find out. She described their study and findings at the 2019 Annual American Association of Equine Practitioners Convention, held Dec. 7-11 in Denver.

Van Erck included in the study 731 European racehorses, Warmbloods, and leisure horses that had been referred to her clinic from 2013 to 2016 for signs of respiratory disease or poor performance. As her team does with all respiratory cases, noted clinical signs such as coughing and nasal discharge;  performed an airway endoscopy, tracheal wash, and bronchoalveolar lavage (BAL); and evaluated each horse’s environment (bedding, forage, pasture access, etc.);