Prevalence of and Risk Factors for Recurrent Airway Obstruction in Geriatric Horses and Ponies

REASONS FOR PERFORMING STUDY: Respiratory disease is a common cause of morbidity in geriatric horses, with a high prevalence of respiratory clinical signs; increasing with increasing horse age. However, owners frequently do not attribute these signs to disease and may not seek veterinary attention. OBJECTIVES: To estimate the prevalence of recurrent airway obstruction (RAO) in the British geriatric equine population using a risk‐screening questionnaire (RSQ) and identify factors associated with RAO. STUDY DESIGN: Cross‐sectional. METHODS: Owners of geriatric horses/ponies enrolled in a previous cohort study were sent a postal questionnaire, combining a validated RSQ with questions regarding management, preventive healthcare, and respiratory‐specific clinical signs. An RSQ score of >0.87 was the positive cut‐off for RAO. Factors associated with RAO were assessed using multivariable logistic regression. RESULTS: The useable response rate was 43.1%, providing data for 285 horses/ponies (median age 23.3 years). Coughing within the preceding year (27.0%) was the most prevalent owner‐reported clinical sign. Among the study population, the apparent prevalence of RAO using the RSQ was 20.7%. 10.5% of horses/ponies were reported to have veterinary‐diagnosed RAO (median age at diagnosis 13 years), of which 33.3% had a positive RSQ score. Data from 273 animals were included in the multivariable model, and factors associated with increased risk of RAO were ridden exercise ≥4 days/week (odds ratio [OR] 3.64; P = 0.005) compared to no exercise; residing on a farm (OR 4.99; P = 0.04) compared to residing on the owner's home premises and having had a respiratory infection within the past 12 months (OR 4.87; P