Retrospective investigation on the prevalence of pulmonary hypertension in dogs with bronchial and upper respiratory diseases

Bronchial and upper respiratory diseases have been associated with hypoxia and subsequent development of pulmonary arterial hypertension (PAH). However, there are no known studies assessing the prevalence of PAH in dogs with these conditions. The aim of this study was to assess the frequency of PAH in dogs with bronchial and upper respiratory diseases. Medical records of dogs with confirmed diagnosis (by endoscopic examination) of bronchial and/or upper respiratory diseases referred for cardiovascular investigation (January 2009 - May 2013) were retrospectively reviewed. Diagnosis of PAH was made by echocardiography (tricuspid regurgitation >2.8 m/s and/or pulmonic regurgitation >2.2 m/s); possible PAH was diagnosed when two or more specific echocardiographic findings were present. 52 dogs (30 with upper respiratory diseases, 17 with bronchial disease and 5 with both) were included. Diagnosis of PAH was performed in 3 dogs (5.7%). Two dogs were considered as probably affected by PAH; a total of 5 dogs (9.4%) resulted in being affected or probably affected by PAH. Our study shows that the prevalence of PAH in dogs with bronchial and/or upper respiratory diseases is low; PAH seems to occur mostly in older dogs and/or with very advanced disease: echocardiography may therefore be a useful tool in this category of patients.