An observational study of the role of indoor air pollution in pets with naturally acquired bronchial/lung disease

BACKGROUND: Indoor air pollution (IAP) is an emerging issue for both human and veterinary patients under the concept of ‘One Health’. The association between IAP and respiratory disease in companion animals has been reported. OBJECTIVES: The present study investigated the relationship between quantifiable indoor air quality and clinical characteristics of naturally acquired bronchial/lung disease in pet dogs and cats. METHODS: A total of 36 clinical cases (20 dogs and 16 cats) with naturally acquired bronchial/lung disease were prospectively recruited. Lower airway samples were collected and analysed, and clinical signs and the information from pulmonary function testing were examined. Indoor air quality was estimated by the average concentration of particles measuring ≤2.5 μm (PM2.5, μg/m(3)) and volatile organic compounds (VOC, ppm) in the animals’ domestic microenvironments. RESULTS: Exposure to IAP was not found to be correlated with the severity of clinical signs, pulmonary function changes or bronchoalveolar lavage fluid cytology in cats with bronchial/lung disease. However, a hypercellular response in canine lower airways was found to be associated with poor indoor air quality, including unacceptable indoor PM2.5 levels (>35 μg/m(3)) or increases in VOC concentration (>1 ppm) in places most commonly frequented by the dogs in the home. CONCLUSIONS: Poor indoor air quality may exacerbate airway disease in pets and should not be ignored in modern society.