Abstract
BACKGROUND: Bordetella bronchiseptica (Bb) is a common respiratory infection in dogs with potentially serious clinical consequences. A subset of Bb cases require referral to tertiary care institutions, yet these dogs lack characterization. HYPOTHESIS/OBJECTIVES: Describe the clinical features, diagnostic findings, management, and outcomes of dogs diagnosed with Bb infections at a tertiary care institution, and evaluate risk factors associated with severe, refractory, or recurrent Bb infections. ANIMALS: Fifty-nine client-owned dogs diagnosed with Bb infections at a tertiary care hospital. METHODS: Retrospective, observational study (1995-2024). Univariable and multivariable logistic regression models were used to identify risk factors associated with negative disease outcomes. RESULTS: Cavalier King Charles Spaniels (CKCS) and Yorkshire Terriers were overrepresented (17.0% and 10.2%, respectively) when compared with hospital admissions from the same period (P <.0001 for both). Nearly 80% of infections were classified as chronic in this population, with a median duration of clinical signs of 30 days. Approximately 40% of cases were classified as severe infections (ie, pneumonia), whereas 54% were classified as refractory. Recurrent Bb infections were uncommon (7%). Mycoplasma spp. coinfections were reported in 37% of cases but were not associated with outcomes. Although no variables were identified as predictors of severe disease, respiratory tract comorbidities (eg, brachycephaly) were associated with refractory infections (P = .04). CONCLUSIONS AND CLINICAL IMPORTANCE: Yorkshire Terriers and CKCS were overrepresented for Bb infections in a referral population, which could indicate underlying risk factors within these breeds. Structural respiratory tract abnormalities may predispose dogs to refractory Bb infections.