Lung Cancer in Cats

No cat parent ever wants to hear their beloved animal is sick, and lung cancer in cats can be a challenging diagnosis because it can go undetected for quite some time. Fortunately, feline lung cancer is rare, and when it does occur, it tends to be in older cats. Here, learn more about the causes, symptoms, and treatment for cat lung cancer.

What is Cat Lung Cancer?

Cancer in cats occurs when cells of the body become abnormal, growing at a swift rate and causing damage to nearby tissue. Lung cancer is the development of tumors in the lungs. 

Cancer cells develop into tumors that invade normal, healthy lung tissue. The tumor then prevents the healthy tissue from doing its job, which is to exchange carbon dioxide and oxygen in the lungs. Sometimes, these tumors can be caused by exposure to toxins in the environment, but more often, there is no known cause of cat lung cancer. 

Males and females of all cat breeds are equally susceptible to lung cancer. The average age at diagnosis is 12 years.

Cancer that starts in the lung is called primary lung cancer, and it is rare for cats to develop this type of cancer. More often in cats, cancer from another part of the body metastasizes, or spreads, to the lung. If this happens in the lungs, it is called metastatic lung cancer. Some types of cancer are more likely to spread to the lungs than others, including cancers of the bone, mammary glands, blood vessels and mouth. Primary lung cancer can also spread from one area of the lungs to another.

Symptoms of Lung Cancer in Cats

Unfortunately, there are rarely early signs of cat lung cancer. Cats are notoriously good at hiding when they don’t feel well, so you may not notice any changes until the disease has progressed. 

Common signs of the condition include decreased appetite, weight loss, decreased energy, and labored breathing. These signs are not specific to lung cancer and can be seen due to various illnesses in cats. Cats with primary lung cancer can develop something called Lung-Digit Syndrome. This is when lung cancer has spread to the muscles or bones in the limbs, especially the toes. Cats may limp, or you may notice swelling or discharge from the foot.

Common Signs of Lung Cancer in Cats

• Decreased appetite (anorexia or inappetence)
• Weight loss
• Decreased energy (lethargy)
• Wheezing
• Coughing 
• Exercise intolerance
• Limping
• Vomiting/Regurgitation

Symptoms of other types of cancer in the chest cavity can mimic the signs of lung cancer.

Causes of Lung Cancer in Cats

Most of the time, there is no known cause of feline lung cancer. Sometimes, environmental exposures can cause lung cancer, such as second-hand smoke. Fortunately, primary lung cancer is uncommon in cats. 

Diagnosing Feline Lung Cancer

The first step in diagnosing lung cancer is a physical exam. The veterinarian will listen to the cat’s heart and lungs and examine the rest of their body. The next step in diagnosing lung cancer is taking X-rays of the chest cavity. Lung tumors are visible on X-ray as areas of abnormal lung tissue. While it is possible to assume a lung cancer diagnosis based on X-rays, a definitive diagnosis requires obtaining a sample of the tissue to examine microscopically for cancer cells. 

Once lung cancer is suspected or diagnosed, your veterinarian will recommend looking at other areas of the body for cancer to determine whether the lung cancer is primary or metastatic (has spread). Tests to look at the rest of the body may include abdominal ultrasound or a CT scan.

Is Cat Lung Cancer Treatable?

Primary cancer of the lung in cats is treatable by surgery, radiation, and/or chemotherapy. If there is a single tumor, it can be removed surgically. The need for follow-up chemotherapy depends on if the tumor can be removed entirely or if there are cancer cells left behind. 

If the cancer is too large to remove or surgery is otherwise not an option, radiation can reduce the size of the tumor and give your cat more time. Chemotherapy is required as part of treatment if there is more than one tumor or if the cancer has spread to other parts of the body. Chemotherapy may include oral and injectable medications. Specific treatment protocols are determined by a veterinary oncologist who tailors a plan to your cat.

Metastatic lung cancer is not considered treatable because it means the cat has late-stage cancer originating in another area of the body. Palliative (comfort) care, including chemotherapy or other medications, is recommended. 

Unfortunately, even when treated, cats with lung cancer have a shortened life span and poor prognosis. On average, cats with primary lung cancer can live several months to a year after treatment. This is because the cancer is likely to grow back. A diagnosis of metastatic lung cancer is fatal within several months. 

The general cost to treat lung cancer in cats depends on what types of treatments are required, the overall health of your cat, and the stage of their cancer. 

Initial diagnostic testing, including CT and tissue sampling, will likely cost $2,000-$3,500. Removal of a lung tumor is typically performed only by specialist veterinary surgeons and costs between $4,000-$8,000. Depending on the protocol, chemotherapy with a veterinary oncologist may cost $3,500-$7,000. 

How to Prevent Feline Lung Cancer

There is no way to prevent cat lung cancer. You can reduce their risk by maintaining a smoke-free home. Regular veterinary visits are essential in keeping your cat healthy and detecting disease early when it is most treatable. If your cat’s behavior, appetite, or energy level changes, she should be seen by a veterinarian.