Tosha is a 12 year old Jack Russell Terrier that presented to the Soft Tissue Service for removal of a mass localized to the right caudo-dorsal lung field (overlapping the liver) discovered incidently in radiography performed two week prior to this presentation. On presentation, Tosha was bright, alert, and responsive to environmental stimuli. Physical examination was unremarkable. Blood collected for quick assessment test (QATS) and gaslyte analysis, which revealed no new abnormalities or contraindications to anesthesia. Tosha was induced under general anesthesia, and taken for a thoracic Computed Tomography (CT) scan. CT revealed a spherical opacity on the right caudal dorsal lung lobe. No evidence of lymphadenopathy or additional pulmonary masses were revealed. Tosha was clipped and prepped for surgery. A right-sided caudal lung lobectomy was performed in the standard fashion. An approximately 1.5cm firm mass was identified on the right caudal lung lobe. The majority of the right caudal lung lobe was removed en masse, a thoracotomy tube was placed, and the lesion was submitted for histopathologic evaluation which subsequently revealed a low grade bronchoalveolar carcinoma. This presentation discusses the clinical and diagnostic signs associated with bronchoalveolar carcinoma, differential diagnoses to rule out, and prognosis. Speculative causes for bronchoalveolar carcinoma will be discussed.