Tumors of the lung can develop primarily from respiratory tissue or metastasize from tumors in other organs.
Lung tumors are more commonly seen in dogs more than seven years old. Early symptoms are unspecific. Affected dogs appear less active and show a varying degree of appetite. Intermittent coughing and labored breathing may occur if larger portions of the lung have been invaded. If the cough is productive, traces of blood may be seen inside the mucus. If the condition progresses, the animal loses weight and becomes anorexic.
Adenocarcinoma is the most common primary (originating-in-the) lungs tumor. However, adenocarcinoma can develop within any the glandular tissues. Carcinoma (cancer) of the mammary glands or lymphoma (cancer that begins in the immune system in cells called lymphocytes) are the types of cancer that are most likely to spread to the lungs and cause metastatic tumors, the type of tumors that spread from their site of origin to other parts of the body.
Tumors can be seen on x-rays of the lung. If detection occurs at an early stage of the disease, chemotherapy or alternatively, treatment with high doses of anti-inflammatory drugs can be successful. Early detection is extremely important, as the prognosis for progressed tumor infiltration is usually poor.
If you suspect that your dog is suffering a tumor of the lungs, consult a veterinary clinic as soon as possible.