Demographic and Historical Findings, Including Exposure to Environmental Tobacco Smoke, in Dogs with Chronic Cough

Background: Controlled studies investigating risk factors for the common presenting problem of chronic cough in dogs are lacking. Hypothesis/Objectives: To identify demographic and historical factors associated with chronic cough in dogs, and associations between the characteristics of cough and diagnosis. Animals: Dogs were patients of an academic internal medicine referral service. Coughing dogs had a duration of cough >or=2 months (n = 115). Control dogs had presenting problems other than cough (n = 104). Methods: Owners completed written questionnaires. Demographic information and diagnoses were obtained from medical records. Demographic and historical data were compared between coughing and control dogs. Demographic data and exposure to environmental tobacco smoke (ETS) also were compared with hospital accessions and adult smoking rates, respectively. Characteristics of cough were compared among diagnoses. Results: Most coughing dogs had a diagnosis of large airway disease (n = 88; 77%). Tracheobronchomalacia (TBM) was diagnosed in 59 dogs (51%), including 79% of toy breed dogs. Demographic risk factors included older age, smaller body weight, and being toy breed (P < .001). No association was found between coughing and month (P= .239) or season (P= .414) of presentation. Exposure to ETS was not confirmed to be a risk factor (P= .243). No historical description of cough was unique to a particular diagnosis. Conclusions and Clinical Importance: Associations with age, size, and toy breeds were strong. TBM is frequent in dogs with chronic cough, but descriptions of cough should be used cautiously in prioritizing differential diagnoses. The association between exposure to ETS and chronic cough deserves additional study.