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

• Published in: Equine veterinary journal Vol. 47
• Format: Journal Article
• Language: English
• Published: British Equine Veterinary Association 01.09.2015
• ISSN: 0425-1644; 2042-3306
• DOI: 10.1111/evj.12486_57

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<0.001). CONCLUSIONS: Risk‐screening questionnaire score‐determined RAO prevalence was considerably higher than the proportion of animals previously diagnosed with RAO. This suggests under‐diagnosis of respiratory problems in geriatric horses, much of which may be unrecognised or undiagnosed RAO. Risk factors identified differ from those previously reported for the general equine population. Ethical animal research: This study was granted institutional ethical approval from the University of Liverpool and the Animal Health Trust. Return of a completed postal questionnaire was taken as informed owner consent. Sources of funding: The original cohort study was funded by the Horse Trust and this study was funded by the Animal Health Trust. Competing interests: None declared.