Diseases That Mimic Lung Cancer In Dogs

lung cancer in dogs

Ok – so your dog has started coughing… 

Or she is having some sort of trouble with her breathing. Maybe there’s some wheezing. Perhaps she’s panting more than usual. 

One of the first things that you might worry about is lung cancer. It’s a common cancer in humans. Nearly everyone knows a person who has died from lung cancer. So you might well think that it would be common in dogs, too, right?

The good news is that primary lung cancer is actually very rare in dogs. Only about 1% of cancers in dogs are lung cancers. Most often, tumors found in the lungs are secondary tumors (metastases). The lungs are a place that cancers tend to spread to more rapidly than other parts of the body. 

Chronic Coughing In Dogs

So what signs might you see if your dog does have tumors in her lungs? Many of the signs will be similar to what you will see with respiratory disease. The most common sign of lung cancer in dogs is a chronic cough. 

But it’s rare that a chronic cough in your dog will be a sign of lung cancer. A chronic cough is usually due to a respiratory disease … like bronchitis or asthma-type allergies. Or it may be because of congestive heart failure.  

These are far, far more common causes of your dog’s coughing, shortness of breath, or difficulty in breathing than lung cancer. 

The bottom line is that most often when your dog develops respiratory symptoms, it won’t be lung cancer. The cause of the cough will nearly always be respiratory disease … or a fluid buildup in the lungs from congestive heart failure

Other common respiratory diseases that might make you worried about cancer are …

If your dog has a chronic cough, you’ll need to rule these out. 

But in some rare cases, it may be a lung cancer (primary or secondary).

When Coughing May Mean Your Dog Has Lung Cancer

There are times when coughing may mean your dog has lung cancer. So what symptoms might make that more likely? 

Coughing Up Blood

If your dog coughs up blood, that’s a sign of something very serious going on in there. This can happen when a tumor damages blood vessels. In very rare cases, this can cause sudden death. 


Occasionally dogs with lung cancer will limp. This can be due to a metastasis in the bone, but that’s very unlikely. 

Usually lameness from lung cancer is due to a condition called hypertrophic osteopathy. Lesions in the chest cavity can cause a change in bone metabolism. This leads to excess growth of bone in the legs … and pain. 

Weight Loss

As is common in general with cancer, you may see a dog who is losing weight despite eating well. You’ll see your dog get dull in the coat, fading away slowly before your eyes. 

Or … No Symptoms

This is an important point to know. Up to 25% of lung tumors in dogs will show no obvious symptoms at all (at least until the cancer is advanced).

If your dog does turn out to have lung cancer, I encourage you to explore holistic treatment options. Find a good homeopath, herbalist or holistic vet who’s experienced in cancer cases. 

RELATED: Natural cancer treatments for dogs …

Diagnosing Your Dog’s Cough

Your dog is coughing or having trouble breathing. And now you know that it’s unlikely your dog has lung cancer. Especially if it’s an acute cough. But what can it be?

Acute coughs are most commonly caused by infections … viral or bacterial. This doesn’t mean you shouldn’t worry about it. 

But if your dog’s coughing becomes chronic, that can be a sign of other serious health issues that need to be treated!

Every chronic cough needs to be worked up by a vet. 

You need to have x-rays, as these are very good at showing if cancer is present. If masses are present in the lungs, your vet may suggest a biopsy. This is the only way to be sure what sort of cancer it is, how aggressive, and the prognosis. Mind you, the prognosis will usually be poor to grave for any dog with lung tumors. 

When Your Dog’s Cough Isn’t Lung Cancer

Congestive Heart Failure (CHF) and chronic respiratory disease are the most common causes of chronic coughing in dogs. You’ll also want to rule out heartworm disease, as it can also cause heart failure and coughing. 

Let’s dig into CHF first.

Congestive Heart Failure

CHF happens when the heart’s ability to pump blood is compromised. This causes fluid to gather either in the lungs or the abdomen. In severe CHF, the lungs will always become damp, congested, and full of fluid. This causes a chronic cough. 

(Interestingly, a 2020 clinical study examined the link between gut dysbiosis and CHF.)

X-rays will often give you a good idea if heart failure is the real problem. Your vet will also listen to the heart, checking for heart murmurs. Heart murmurs are usually caused by damage to the heart valves. 

CHF sounds scary, but it can often be managed quite well holistically. Several herbs, supplements and foods can help you avoid prescription drugs for your dog … until she needs palliative care. 

RELATED: Congestive heart failure in dogs … 

Chronic Respiratory Diseases

These can be hard to diagnose and treat. There are a whole lot of different things that can cause chronic respiratory disease. So you’ll need your vet’s help to pin down the cause. 

Inflammatory Disease

There may be inflammatory causes such as chronic bronchitis or eosinophilic bronchopneumopathy. 

Chronic Bronchitis

Middle aged and older dogs can develop chronic bronchitis for many reasons. These include heart or lung disease, smoke inhalation, or exposure to chemical fumes. It’s more common in smaller dogs. Coughing spasms that last for 2 months or more may be a sign of chronic bronchitis. 

Eosinophilic Bronchopneumopathy 

This disease causes thick fluid and white blood cells to get into the lungs. It may be an allergic reaction, or a virus or parasite. Dogs with this condition will be lethargic. They may have difficulty breathing during normal exercise. 

Infectious Diseases

Infectious causes that cause coughing include bacteria, fungi, or viruses. Or your dog could have a parasite like lungworm or heartworm. 


Lungworms (called Oslerus osleri) live in nodules in dogs’ tracheas. Their eggs hatch there. Fecal analysis can sometimes confirm a lungworm diagnosis. Otherwise, your vet may take X-rays. He might examine the airways using an endoscope (bronchoscopy). That allows him to look for eggs, larvae and white blood cells in the trachea. 


Coughing could be a sign of advanced heartworm disease. However, vets regularly test dogs for heartworm infection … so most dogs are unlikely to have a case of heartworms that advanced. 

If your dog’s coughing but hasn’t been tested lately … your vet may suggest checking for heartworm infestation using …  

  • Bloodtests
  • Echocardiogram (heart ultrasound)
  • Chest x-rays 

Conventional Heartworm Treatment

If your dog does have heartworms and you opt for conventional heartworm treatment, beware. It’s highly risky. There are natural options that are much safer, including herbal remedies and homeopathy. When conventional drugs kill off heartworms, the dead worm fragments can get into the lungs. This can cause severe respiratory problems … and even death. That’s why dogs going through conventional treatment must be kept very quiet. If your dog coughs, spits up blood, or has trouble breathing while she’s getting heartworm treatment, get her to your vet immediately. These complications can be life-threatening. And your dog will likely have to be hospitalized.  

RELATED: Why I don’t give my dogs heartworm medicine … 

Degenerative Diseases

Your dog may have a degenerative condition like tracheal collapse or bronchiectasis. And there are rare, weird problems like idiopathic pulmonary fibrosis. 

Tracheal Collapse

Tracheal collapse is most common in toy and miniature breeds … especially if they’re obese. Dogs with heart or lung disease are also prone to tracheal collapse. Symptoms are labored breathing and a dry, honking chronic cough. 


Bronchiectasis is a chronic lesion causing permanent narrowing of the bronchi. It can cause long-term breathing difficulties and recurring infections. It’s more common in middle aged or senior dogs. Symptoms include coughing (sometimes producing blood or phlegm), exercise intolerance and sometimes fever.

Research shows that there may be a link between tracheal collapse and bronchiectasis.

Idiopathic Pulmonary Fibrosis

In dogs with pulmonary fibrosis, the lungs become scarred, thickened and stiff. This makes breathing difficult. Idiopathic means the cause isn’t known. Other types of pulmonary fibrosis can stem from chronic injury from other diseases … like bronchitis, pneumonia or congestive heart failure.  Symptoms are respiratory distress, reduced appetite and coughing.  While a lung biopsy is needed for a definitive diagnosis, it’s rarely done due to high cost and high risk. 

This is a chronic, incurable condition that can be progressive.  Conventional vets will just manage symptoms with a range of drugs, including steroids. But homeopathy can be a much better option. A good homeopath will prescribe remedies that manage symptoms as well as help address the underlying causes. 

Diagnosing Chronic Respiratory Disease

Again, you’ll need your vet’s help to figure out what’s causing your dog’s chronic coughing. Lung issues, like cancer, can be difficult to diagnose in dogs. 

X-rays may show that there is something going on, but to get a definitive diagnosis can be all kinds of tricky. You can spend a LOT of money on invasive diagnostic tests like bronchoalveolar lavage … and never really know exactly what the cause is. But sometimes these tests do give you good information. (Bronchoalveolar lavage requires general anesthesia so the vet can place a breathing tube into the trachea. This allows him to examine the airways and take fluid samples.) 

Holistic Treatment For Chronic Respiratory Disease

Can you treat chronic respiratory disease holistically? That will depend on your dog’s individual condition and diagnosis. Holistic treatment may not be enough in some cases. 

Whatever chronic respiratory problem your dog has … I highly recommend you work with a skilled homeopath or herbalist. 

Even if it does turn out to be lung cancer, research in people shows homeopathy can be an effective therapy in some types of lung cancer.

Sometimes, using a humidifier or nebulizer can help. Natural cough suppressants such as licorice or lemon and honey may help. I highly recommend licorice and mullein tea. Other herbs that can help are aniseed and thyme. 

If your dog has a wet cough with a lot of mucus, then marshmallow and hyssop may be worth considering. And nettle is a good all-round tonic herb. 

You can give all these herbs I’ve mentioned as a tea for your dog. 

Making Herbal Tea For Your Dog

To give herbal teas to your dog … first make the tea using the package instructions. 

Let the tea cool. Then, assume a 1 cup dose is for a 150 lb human, and adjust that dose for your dog’s bodyweight. 

Give one or twice a day as needed, alone as a drink, or with food. 

RELATED: Natural alternatives to cough medicine for dogs …

So, if your dog has a chronic cough, chances are he doesn’t have lung cancer. But you’ll likely need your vet’s help getting to the bottom of whatever chronic respiratory problem she has. 


Seo Jet al. The gut microbiome in dogs with congestive heart failure: a pilot study. Sci Rep. 13, August 2020.

Rozanski E. Canine Chronic Bronchitis: An Update. Vet Clin North Am Small Anim Pract. March 2020.

Johnson LR,  et al. Eosinophilic bronchitis, eosinophilic granuloma, and eosinophilic bronchopneumopathy in 75 dogs (2006-2016). J Vet Intern Med. September 2019. 

Canonne AM et al. Detection of specific bacterial agents by quantitative PCR assays in the bronchoalveolar lavage fluid of dogs with eosinophilic bronchopneumopathy vs. dogs with chronic bronchitis and healthy dogs. Vet J. February 2018. 

Mayer P et al. Bronchoalveolar lavage in dogs; analysis of proteins and respiratory cells. Zentralbl Veterinarmed A. June 1990.

Della Maggiore A. An Update on Tracheal and Airway Collapse in Dogs. Vet Clin North Am Small Anim Pract. March 2020. 

Marolf A et al. A retrospective study of the relationship between tracheal collapse and bronchiectasis in dogs. Vet Radiol Ultrasound. May-June 2007. 

[Proceedings]. Claire R Sharp DVM BSc BVNS DACVECC. Managing pulmonary fibrosis in dogs. DVM360. September 2011. 

Laurila HP et al. Update on Canine Idiopathic Pulmonary Fibrosis in West Highland White Terriers. Vet Clin North Am Small Anim Pract. March 2020. 

Frass M, et al. Homeopathic Treatment as an Add-On Therapy May Improve Quality of Life and Prolong Survival in Patients with Non-Small Cell Lung Cancer: A Prospective, Randomized, Placebo-Controlled, Double-Blind, Three-Arm, Multicenter Study. Oncologist. December 2020. 

Moshe Frenkelet al. Complementary and Integrative Medicine In Lung Cancer: Questions And Challenges. The Journal of Alternative and Complementary Medicine. September 2018.


Get instant access to easy-to-make and affordable recipes. Plus get new recipes delivered right to your inbox.

Recipe Cards for Making Raw Dog Food

Related Posts