What it is: a cancer that starts in the lung itself (not spread from elsewhere). The most common type is adenocarcinoma (arising from the small airway/alveolar lining).

 

Dogs and cats can also develop other lung carcinomas, but adenocarcinoma is the “typical” primary lung cancer.

 

How common: Primary lung cancer is uncommon—roughly ~1% of all tumours in dogs, and <1% in cats.

 

Main treatment: Surgical removal (lung lobectomy) is the backbone of therapy when a single lobe is affected and the pet is a good anesthesia candidate.

Survival can be months to years, highly dependent on tumor size, stage, and whether nearby lymph nodes are involved.