Pulmonary adenocarcinoma is a common and aggressive form of lung cancer in dogs, accounting for nearly 80% of canine lung neoplasia cases. The primary treatment is surgical tumor removal, sometimes combined with chemotherapy or radiation therapy for inoperable cases. Prognosis depends on tumor size and grade, ranging from over 16 months for small, low-grade tumors to only 3 months for high-grade, metastatic cancers despite treatment.