Long-term outlook and risk factors for bronchomalacia in dogs

Abstract

BACKGROUND: Bronchomalacia (BM) is an important respiratory disease in dogs that frequently presents with comorbidities such as pulmonary hypertension (PH) and other respiratory conditions. However, the overall prognosis and risk factors for disease progression remain poorly investigated. HYPOTHESIS/OBJECTIVES: Assess the long-term outcomes of dogs with BM and identify clinically relevant prognostic factors. ANIMALS: Client-owned dogs (n = 72) with bronchoscopy-confirmed BM. METHODS: Prospective, observational cohort study. Dogs with confirmed BM were followed from December 2013 to February 2025. Unfavorable clinical events related to BM were recorded, including the development of PH, pneumonia or pneumonitis, and all-cause or cardiorespiratory mortality. Signalment, BM severity, and clinically relevant comorbidities were analyzed for their prognostic value using survival analysis. RESULTS: After diagnosis by bronchoscopy, dogs with BM had a median survival time of 998 days (95% confidence interval [CI], 896-1010) for all-cause mortality and 1323 days (95% CI, 1074-1572) for cardiorespiratory mortality; approximately two-thirds of deaths were attributed to cardiorespiratory causes. Pulmonary hypertension and pneumonia or pneumonitis occurred in more than one-third of the cohort. In multivariable analyses, older age, inflammatory airway disease requiring corticosteroid treatment, and PH were associated with pneumonia or pneumonitis development. Older age, PH, and severe BM were associated with all-cause mortality. Tracheal collapse grade III/IV, PH, and inflammatory airway disease requiring corticosteroid treatment were associated with cardiorespiratory mortality. CONCLUSIONS AND CLINICAL IMPORTANCE: Bronchomalacia in dogs is associated with substantial cardiorespiratory mortality. Identification of key prognostic factors may assist in risk stratification and long-term management.