Lung cancer in dogs and cats

18th Jan, 2022

Written by Dr Anri Celliers BSc, BVSc (Hons), MMedVet (Med), Small Animal Internal Medicine Specialist – Onderstepoort Veterinary Academic Hospital

Did you know that pets can develop lung cancer? Indeed, just like us, dogs and cats are also at risk of developing this condition, and it’s therefore important to learn more about lung cancer to provide the best care for your furry friend. 

What is it?

Lung cancer (pulmonary neoplasia) is caused by the growth of abnormal cells within the lung tissue. These cells can be benign, meaning that they don’t invade neighbouring tissue, or malignant. Malignant tumours tend to invade surrounding tissues and spread to distant organs. They can also cause damage to tissue, leading to impairment of organ function.

Lung cancer in dogs and cats can be primary (rarely) or secondary (metastatic). Primary tumours originate and start growing in the lung tissue, whereas secondary tumours result from spread of cancer from elsewhere in the body. Cancer spreading (metastasising) to the lungs is so common that lung radiographs (x-rays) are usually included in the work-up for different types of cancer.

Tumour cells can invade normal lung tissue, resulting in a decreased ability of the lungs to take up oxygen and transfer it to the bloodstream. It can also result in fluid build-up in, or compression of, lung tissue.

In contrast to humans, exposure to tobacco smoke is a yet unproven cause of primary lung cancer. Some studies have however shown an association between environmental dust exposure and lung cancer development. Further research looking into the different causes of lung cancer in dogs and cats is warranted.

Signs of lung cancer can be subtle at first with most pets not showing signs until it’s become advanced. Pets may have a poor appetite, weight loss, and get tired easily. As the disease progresses, signs may include coughing and difficulty breathing.

How is it diagnosed?

To diagnose lung cancer, the veterinarian will do a full physical examination, including auscultation (listening) of the lungs and checking for other signs of cancer. Radiographs of the lungs can be taken to see if masses are visible. Bloodwork may be done to check your pet’s internal organ function.

Other tests such as ultrasound can be used to look for signs of cancer elsewhere in the body. In some cases, a sample of the mass will have to be collected either via a needle and syringe or with a surgical biopsy to obtain a diagnosis.

How is it treated?

Some lung cancers can be surgically removed, especially if it’s a primary tumour with only one lung lobe affected. Chemotherapy and radiation are other available treatment options, depending on what type of cancer is present. In cases where the cancer is advanced and viable treatment options aren’t available, palliative (supportive) care is provided. This may include pain medications, cough suppressants, anti-inflammatory medications, and appetite stimulants.

Each case of lung cancer in dogs and cats is unique, and it can sometimes be difficult to predict the outcome and response to therapy. Given this uncertainty, treatment decisions are tailored to the individual pet with the aim to achieve a good quality of life for as long as possible.

Testimonial story: One Day At A Time

Photo credit: Tamed & Framed

Written by Ros Silke

Jonty was rescued as a tiny puppy by African Tales in August 2009. He found his forever home with me soon after, where he joined little brother Flecky.

Jonty is a very special dog who must just speak… he’s honestly my best friend who’s unconditionally loved me and been at my side for the last 12 years. Together we’ve faced losing my mom, my dad, and our little Flecky. Those big eyes just show love!

Jonty loves everybody but is afraid of other dogs after a nasty incident when he was little. He’s such a character – he enjoys swimming, going for drives in the car, running around with the rugby boys at Hammies, and chasing birds and his beloved tennis ball. Words cannot describe what a blessing he’s been in my life.

On the 29th of September 2021 we received the heart-breaking news that Jonty had advanced lung cancer.

I knew something was off. He has arthritis in his shoulders and slight hip dysplasia, so the vets started him on pain medication. When the panting didn’t stop, I asked them to do a chest x-ray to make sure. There were spots on his lungs. My worst nightmare!

Working closely with Jonty’s vet, Dr Martin Jakoby of VetPoint, Jonty is coping well. He’s eating two good meals a day and still enjoys his snacks in between. Thankfully, he’s doing really well; he has no further symptoms at this stage.

It’s important to me that he has a good quality of life and that he’s pain-free. I know we’re on borrowed time, but each day is a blessing, and we’re taking it one day at a time. How I’ll be able to say goodbye to this furbaby, I don’t know, but for now I’m just enjoying every cuddle I can get.

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