Primary lung tumors are cancers that arise in the lung tissue of both dogs and cats. They are rare in both species, but slightly more common in dogs.

The most common type of tumor is a carcinoma. Carcinomas are malignant tumors that develop from the epithelial tissues in the lungs. They may be primarily derived from the lung tissue itself, or the airways or bronchioles.

The exact cause of lung cancer is not known, but there appears to be an increased incidence of cancer in dogs that live in urban environments, as well as dogs that are exposed to second hand smoke. Lung cancer is generally diagnosed in older animals, with an average age of about 11 years, but it can also be seen in younger pets.

There are no known predispositions with respect to breed or sex and the development of lung tumors. However, most lung cancer is seen in medium to large sized dogs.

What to Watch For

Chronic (long term) coughing

Lethargy

Trouble breathing

Weight loss

Coughing up blood

Anorexia (lack of appetite)

Lameness

Diagnosis

Complete history and physical exam

Complete blood count (CBC)

Biochemical profile

Urine analysis

Chest radiographs (X-rays)

Abdominal radiographs or ultrasound exam

Fine needle aspirate of lung mass

Trans-tracheal aspirate or bronchoscopy

Mass biopsy

Treatment

Surgical removal of the lung tumor

Chemotherapy may be recommended in selected cases.

Home Care

Monitor breathing patterns and monitor for recurrence of original clinical signs. Avoid exposure to second hand smoke.