Chronic Productive Cough in an Immunosuppressed Patient due to Biologics: A Rare Case of <i>Bordetella bronchiseptica</i> Pulmonary Infection

<i>Bordetella bronchiseptica</i> is a zoonotic pathogen that can infect immunocompromised humans. We present a 59-year-old man on immunotherapy for inflammatory bowel disease, with persistent expectorant cough for 18 months. Computed tomography (CT) demonstrated migratory lung infiltrates. Bronchoalveolar lavage cultured <i>B. bronchiseptica</i> resistant to initial antimicrobial therapy, highlighting the diagnostic challenges in immunosuppressed patients.