Lung Cancer in Dogs: Symptoms, Diagnosis & Vet-Verified Natural Support

Lung cancer in dogs is a rare but severe condition. It is an aggressive cancer that is usually diagnosed in older dogs. However, it can affect any breed of dog at any age.

It can be primary, when it develops directly in the lungs, or secondary (metastatic), when the first tumor appears in another area of the body and the cancer cells have spread to the lungs.

In the early stages, the clinical signs may be nonspecific or absent. For this reason, the disease may be discovered later or too late. However, lung cancer in dogs can be diagnosed incidentally during routine x-rays. Symptoms of lung cancer in dogs may include persistent coughing (sometimes with blood), difficulty breathing, lethargy, and loss of appetite.

Lung cancer in dogs can progress rapidly, affecting the dog's quality of life. Therefore, early diagnosis and an appropriate treatment plan are essential. Depending on how advanced the disease is, treatment may include surgery, radiation therapy, chemotherapy, or symptomatic care.

In this article, you will learn about lung cancer in dogs, its clinical signs, how it is diagnosed, the conventional treatments and natural products and supplements, and much more.

What Is Lung Cancer In Dogs?

Lung cancer in dogs is a condition in which abnormal cells in the lungs multiply chaotically and uncontrollably, forming tumors (masses or growths). It is usually diagnosed at the age of 10-12 years. However, it can develop at any age and any breed.

As previously mentioned, lung cancer can be primary, when it develops directly in the lungs, or secondary, when cancer cells from other tumors in the body spread to the lungs. Regarding primary lung cancer, it is malignant in approximately 80% of cases, the remaining 20% being benign (non-cancerous). In this article, we will only present malignant lung cancers in dogs.

In dogs, lung cancer is rare, representing less than 1% of all types of cancer found in this species – approximately 2 to 4 out of every 10,000 dogs are diagnosed with lung cancer. However, it can be severe and difficult to treat due to its location and rapid spread to other organs.

Types of Lung Cancer in Dogs

Lung cancer in dogs can be classified into several types. The most common are:

1. Pulmonary adenocarcinoma and alveolar carcinoma

These are the most common types of primary lung cancer in dogs, occurring in more than 90% of cases. Pulmonary adenocarcinoma is a form of cancer that develops in mucus-producing (glandular) cells, leading to solid tumors. It can be localized and can spread (metastasize) to other parts of the body, such as: lymph nodes, chest cavity, bones, and brain.

Alveolar or bronchoalveolar carcinoma develops in epithelial tissues – tissues that line the internal organs of the body and are found in the skin – leading to the formation of tumors.
Some breeds are more predisposed to developing pulmonary adenocarcinoma or bronchoalveolar carcinoma, such as:

• Boxer
• Doberman Pinscher
• Australian Shepherd
• Irish Setter
• Bernese Mountain Dog

Lung cancer in dogs, like other types of cancer, must be graded (i.e., classifying cancer cells based on how abnormal they look under a microscope and how quickly they are likely to grow and spread to other parts of the body). The grade of the cancer helps in making treatment decisions, determining the prognosis, and so on. According to the VSCO (Veterinary Society of Surgical Oncology), grade I carcinomas spread slowly, grade II moderately, and grade III more rapidly. As with any type of cancer, grade I cancers have a better prognosis.

2. Lung Squamous Cell Carcinoma (SCC)

This type of cancer arises from squamous and non-squamous epithelial tissues in the bronchi. Lung SCC is less common than pulmonary adenocarcinoma and carcinoma in dogs. It is an aggressive cancer with a poor prognosis. This type of cancer can spread to other organs.

3. Pulmonary Lymphoma

Lymphoma is a form of cancer that affects the lymphatic system. In the case of lung cancer, it can affect the lungs and adjacent lymph nodes – pulmonary lymphoma is usually a secondary (metastatic) type of lung cancer in dogs. The prognosis is poor, and without treatment, the disease progresses rapidly, with the affected dog having a life expectancy of a few weeks.

4.  Pulmonary Histiocytic Sarcoma

It is a rare form of primary lung cancer, which originates in the lung parenchyma, in dendritic cells or macrophages. When it occurs in other areas of the body (e.g., bones, joints, and skin), it frequently spreads to the lungs, spleen, and liver. Some dog breeds are more prone to developing histiocytic sarcoma, such as: Bernese Mountain dogs, Flat-Coated Retrievers, and Rottweilers.

5. Other Types Of Metastatic Lung Cancer In Dogs

Metastatic lung cancer in dogs occurs when cancer from another part of the body spreads to the lungs. It is more common than primary lung tumors in dogs. It can arise from different types of malignancies, the most common of which are:

Carcinomas

Carcinomas are the most common types of cancer that metastasize to the lungs. They originate from the epithelial tissues.

Mammary carcinoma – This is one of the most common types of cancer that spreads to the lungs in dogs.

Transitional cell carcinoma (TCC) – This type of cancer originates in the bladder and can spread to the lungs. Studies show that 14% of dogs are diagnosed with pulmonary metastasis at the time of diagnosis, and 50% at the time of death.

Anal sac adenocarcinoma – This type of cancer is highly metastatic, often spreading to the lymph nodes and lungs.

Thyroid carcinoma – This type of cancer can metastasize aggressively to the lungs and regional lymph nodes.

Sarcomas

Sarcomas are types of cancer that arise from connective tissues, such as bones, muscles, and blood vessels.

Osteosarcoma – This is a type of bone cancer that frequently metastasizes to the lungs, often before the primary tumor is detected.

Hemangiosarcoma – It is a type of cancer of the blood vessels that usually spreads rapidly to the lungs.

Fibrosarcoma – It is a cancer of fibrous connective tissue that can metastasize to the lungs and regional lymph nodes.

Melanoma

Canine melanoma, both oral and digital forms, is very aggressive and often metastasizes to the liver, lungs, and regional lymph nodes. Pulmonary metastases may appear as multiple nodules.

What Are The Signs Of Lung Cancer In Dogs?

The clinical signs of lung cancer in dogs are often subtle or absent in the early stages, being discovered incidentally on routine chest X-rays. However, in advanced stages, the type, size, and extent of the tumor can lead to varying clinical signs. Here are some of the clinical signs you may notice if your dog has lung cancer:

Exercise intolerance and lethargy

If your dog suffers from lung cancer, you may notice that they get tired quickly even after minimal exercise (e.g., after light play, short walks, going up the stairs, etc.). Because of this, they will end up avoiding play, walks, etc., becoming lethargic.
In addition, the lack of proper oxygenation can lead to generalized weakness – your dog will sleep more, have difficulty getting up, move slowly or unsteadily, or you will notice muscle tremors.

Persistent cough

This is one of the most common clinical signs seen in dogs with lung cancer. The cough may be dry, irritating, or productive (expectorating – with secretions). In late stages of the disease, the affected dog may also eliminate blood (hemoptysis) and mucus.
The cough from lung cancer is not remedied with antibiotics or anti-inflammatory medication. Therefore, if your dog’s coughing is not remedied with medication, it can mean that there is another underlying issue.

Difficulty breathing

Lung cancer leads to the appearance of tumors, which can obstruct the airways, reducing the pet’s oxygenation. This in turn leads to difficulty breathing. In addition, the affected dog may have shallow, heavy, or rapid breathing.
Dogs with breathing difficulties have a characteristic position – they sit with their neck stretched forward and their elbows away from the body (in medical terms, it is called orthopneic position or breathing).
In severe cases, when the body is not properly oxygenated, blue color of the mucous membranes (cyanosis) may also appear.

Loss of appetite

In general, sick dogs will not have the same appetite due to the illness and the fact that they are not feeling well. For this reason, they will also lose weight. In some cases, dogs still eat normally, but, nevertheless, they continue to lose weight.
In the advanced stages of lung cancer in dogs, they may refuse food completely.

Chest pain

It is difficult to tell when a dog is in pain. However, reflex mechanisms will help them protect themselves from further pain. For example, in lung cancer, the affected dog will avoid certain positions or will react negatively when their chest is touched.

Clinical Signs Associated With Metastasis

If the primary lung cancer has metastasized to other areas of the body, clinical signs may vary depending on the affected organ, such as:

• Lameness, pain, swelling of the limb, and spontaneous fractures – if it has metastasized to the bones.
• Seizures, loss of balance, and sudden changes in behavior – if the lung cancer has spread to the brain.

Stages of Lung Cancer in Dogs

To find out how advanced the cancer is and how far it has spread in the body, the veterinarian will stage/classify it based on the size of the tumor, the degree of invasion, and the presence of metastases.

Stage I

At this stage, the lung cancer is incipient, the tumor is small and located in a single lung lobe. There are no metastases.

This stage is most often asymptomatic, being detected incidentally on routine X-rays.

Stage II
At this stage, the tumor grows and begins to invade the surrounding tissues. There are no metastases.

Clinical signs in this stage may include mild cough, fatigue, and weight loss.

Stage III

At this stage, the lung cancer advances locally, invading important structures (trachea, diaphragm, or chest walls). In addition, it spreads to regional lymph nodes but there are no distant metastases.
Clinical signs may include a persistent cough, difficulty breathing, severe lethargy, and weight loss.

Stage IV

At this stage, lung cancer has spread throughout the body to other tissues and organs (bones, brain, as well as other parts of the lungs).

Clinical signs may include coughing up mucus and blood, difficulty breathing, bone pain in the case of bone metastases, generalized weakness, or neurological problems in case the cancer has spread to the brain.

How Do Veterinarians Diagnose Lung Cancer In Dogs?

Because the symptoms of lung cancer in dogs are often nonspecific and similar to other respiratory conditions, diagnosis involves several steps.

1. Clinical Examination

This stage includes the medical history of your dogs and the actual physical examination. Medical history is the process by which the veterinarian collects information about your dog's past medical issues and the clinical signs present in order to establish a diagnosis and develop an appropriate treatment plan. The veterinarian will ask questions about your dog's coughing, difficulty breathing, respiratory effort, appetite and weight loss, etc.
During the actual physical examination, the vet will listen to your dog's lungs with a stethoscope (auscultation) to detect any abnormal lung sounds, palpate lymph nodes to determine if they are enlarged, look at the color of your dog's mucous membranes, and then recommend a series of additional tests for a more accurate diagnosis.

2. Additional Tests

Blood and urine tests

These tests do not confirm a cancer diagnosis, but they help the veterinarian assess your dog’s overall health. Therefore, they may recommend the following:

• Complete blood count (CBC) – It may indicate anemia, infection, and/or inflammation.
• Blood chemistry – measuring liver enzymes and kidney markers may be helpful if they want to anesthetize or sedate your dog or before administering certain treatments (such as chemotherapy).
• Urine tests.

Thoracic X-rays

Chest X-rays are essential for detecting lung cancer, whether primary or secondary. The images may show a single mass (which is usually seen in primary lung cancer) or multiple small nodules (suggesting lung metastases). In addition, pleural effusion (fluid accumulation between the lungs and the membrane that covers them) may be seen, as well as enlarged lymph nodes, and other changes that may occur when lung cancer has spread into the thoracic cavity.

In some cases, especially in the early stages of lung cancer in dogs, small tumors are not visible on X-rays.

Computed tomography (CT)

CT is the most accurate method for diagnosing lung cancer in dogs because it provides detailed images of tumor extension and possible metastases – MRI is less sensitive. It can detect small or difficult-to-see tumors on X-ray. In addition, this method of investigation may be recommended before surgery to assess if the tumor is operable.

Abdominal ultrasound (AUS)

In cases where lung cancer has spread to the lymph nodes, AUS can help identify if they are enlarged. Additionally, in cases of pleural effusion, AUS can help guide the thoracic puncture (thoracocentesis) to collect a sample of the fluid - pleural fluid cytological exam.

Bronchoscopy (endoscopy of the airways)

This method of investigation involves using a flexible tube with a video camera that is inserted into the airways to view the inside of the dog’s lungs. This way, the veterinarian can look for inflammation, foreign objects, and masses, or even collect tissue samples to analyze the cell population. In addition, bronchoscopy allows for bronchoalveolar lavage to be performed to collect cells. For this procedure, sterile fluid is introduced into the airways, which is then extracted and studied under a microscope. Bronchoalveolar lavage allows for definitive diagnosis.

Lung biopsy

This method of investigation confirms the diagnosis of cancer as well as its type and grade. There are two types of biopsies in lung cancer, such as:

• Ultrasound-guided biopsy
• Surgical biopsy - it can be partial (when the vet removes a part of the tumor) or total (when the vet removes the whole tumor).

Additional tests to identify metastases

If your veterinarian suspects that the disease has spread to other areas of the body, they may recommend the following:

• Abdominal ultrasound – to check the internal organs.
• Brain MRI – to check for brain metastasis.
• Bone X-rays – to check for bone metastasis.

Early diagnosis increases the chances of effective treatment. If you notice suspicious clinical signs in your dog, consult a veterinarian as soon as possible.

How Do Veterinarians Treat Lung Cancer In Dogs?

The veterinarian will choose the treatment method depending on the type and stage of your dog's lung cancer.

1. Surgical removal of the tumor

This treatment method is indicated for primary lung cancers in dogs. When the tumor is isolated and without obvious metastases, and the dog is healthy enough to undergo medical intervention, surgical removal of the tumor is the preferred method of treatment. The procedure is called pulmonary lobectomy, which means the removal of the lung lobe in which the tumor is located. In some cases, depending on the location or if the veterinarian wants to prevent the cancer from spreading, they may choose to remove the entire affected lung (if the other one is functioning within normal parameters).

In addition, the veterinarian may choose to remove the regional lymph nodes to see if the cancer has spread to them.

Life expectancy after surgery can be 12 months, sometimes 2 years if there are no metastases. In cases where lung cancer is aggressive, it can recur even if the primary tumor has been surgically removed.

In cases of lung metastases (secondary lung cancer), when multiple, small nodules develop in the lungs, veterinarians may recommend other therapeutic methods.

2. Chemotherapy

This treatment method is usually recommended for metastatic lung cancer or when the primary lung cancer is advanced or aggressive. Chemotherapy can help control tumor growth.

3. Radiotherapy

If the primary lung tumor cannot be surgically removed, your veterinarian may recommend radiotherapy – a non-invasive and painless treatment method that uses radiation. Your dog may need 1-5 radiotherapy sessions, which are determined by your dog’s oncologist.

4. Symptomatic treatment

If your dog’s lung cancer cannot be treated with the methods mentioned above, your vet may opt for treatments that will improve the symptoms and quality of life. Examples of medications that may be recommended in this case are steroidal anti-inflammatories, bronchodilators, diuretics, or analgesics.

Are There Any Natural Products For Lung Cancer In Dogs?

There are some herbal and natural supplements that can help your dog with their fight against lung cancer. Some of these remedies are:

Reishi mushrooms (Ganoderma lucidum)

Research performed on humans suggests that Reishi mushrooms may reduce protein synthesis and slow tumor growth by influencing signaling pathways involved in cell survival and proliferation. These results indicate that these mushrooms could be a promising natural option for patients with breast cancer and other types of cancer in humans, while also supporting the immune system and slowing tumor growth.

Turkey Tail mushrooms (Coriolus versicolor)

Turkey tail mushrooms contain compounds such as beta-glucans, a type of β-d-glucose polysaccharides, known for their ability to stimulate the immune system and slow tumor growth. Studies on these polysaccharides have shown benefits in various types of human cancer, including gastric, breast, intestinal, and lung. They are used as adjuvant therapy in oncology patients due to the minimal side effects.

Shiitake mushrooms (Lentinus edodes)

Shiitake mushrooms are known for their anti-cancer and immunomodulatory properties. Like turkey tail mushrooms, they contain beta-glucans, compounds with anti-cancer and pro-apoptotic effects, promoting programmed cell death. One of the most well-studied compounds in Shiitake mushrooms is lentinan, which has been shown to have beneficial effects in patients fighting cancer.

SHIITAKE from Zumalka is a natural supplement containing only Shiitake mushrooms, designed to strengthen your dog's immune system, support liver health and help dogs with infections and cancer.

Birch polypore (Fomitopsis betulina)

PIPTOPET from Zumalka is a mother tincture designed to support dogs in their fight against cancer and accelerate recovery. Its main ingredient, birch polypore (Fomitopsis betulina), is a medicinal mushroom that has been used for centuries for its therapeutic properties.

Studies conducted on mice, dogs, and monkeys have shown that this mushroom has antiviral, antibacterial, antitumor, anti-inflammatory, and antioxidant effects. It helps to strengthen the immune system and support the natural healing processes.

Suitable for all dogs, including those diagnosed with cancer, PIPTOPET can be an effective natural option in the management of oncological conditions.

For increased benefits, it is recommended to use it together with the following natural supplements:

• TONICPET #4: Supports the body's natural immune response by enhancing oxygen delivery to all areas, helping to maintain your dog's overall well-being.
• TONICPET #5: Promotes healthy circulation, ensuring optimal function across all bodily systems.
• TONICPET #7: Aids in the fight against cancer by improving oxygen circulation, which strengthens the immune system.
• TONICPET #10: Helps regulate the body's pH levels, creating an environment less favorable for cancer cell growth.

When combined with TONICPET #4, #5, #7, and #10, PIPTOPET can support the body's natural healing response by altering the dog's tissue environment. Since cancer thrives in an inflamed and acidic state, these products work together to create a less favorable environment for its growth.

Turmeric (curcumin)

Turmeric offers significant benefits for the body due to its anti-inflammatory, antitumor, and antioxidant properties. It supports the health of cartilage and connective tissue, alleviates joint stiffness, combats free radicals, and helps maintain a normal, healthy inflammatory response.

The dosage of turmeric is 1/8 to 1/4 teaspoon per day for every 10 pounds of body weight.

CBD oil

Cannabidiol (CBD) oil is derived from the cannabis plant and has been studied for its potential to improve various clinical symptoms related to cancer and its treatments. Research suggests that CBD may help alleviate pain and inflammation. Additionally, studies indicate that it could aid in the fight against cancer by promoting programmed cell death (apoptosis) and reducing cell viability. One study also shows that when combined with chemotherapy drugs like mitoxantrone and vinblastine, CBD oil’s effects are enhanced in dogs with urothelial carcinoma. Furthermore, there are reports suggesting that cannabinoids like THC and CBD can help reduce nausea, vomiting, and loss of appetite in patients suffering from cancer.

Frequently Asked Questions (FAQs)

How Long Can A Dog Last With Lung Cancer?

If the cancer is in its early stages, and the tumor is surgically removed, life expectancy is 1-2 years. If the cancer is in an advanced stage or the affected dog is not treated, life expectancy drops to about 2 months.

What Are The Symptoms Of Late-stage Lung Cancer In Dogs?

Clinical signs in late-stage lung cancer in dogs may include the following clinical signs: coughing up mucus and blood, difficulty breathing, bone pain in the case of bone metastases, generalized weakness, or neurological problems in case the cancer has spread to the brain.

What Can I Do To Help My Dog With Lung Cancer?

If your dog has been diagnosed with lung cancer you can do the following to help them: offer them a balanced, nutritious diet, manage their pain with pain medication, maintain proper hydration, provide comfort by creating quiet, comfortable places where they can rest, and consider symptomatic treatment and natural supplements like CBD oil, turmeric, PIPTOPET, SHIITAKE, TONICPET#4, #5, #7, and #10 by Zumalka.

What Is The Progression Of Lung Cancer In Dogs?

Lung cancer in dogs progresses from stage I, where the tumor is small and has not spread to other tissues, to stage IV, where the cancer has spread throughout the body, especially to the bones and brain. In stage I lung cancer, there are usually no clinical signs. On the other hand, in stage IV, the dog can cough with mucus and blood and have difficulty breathing, bone pain, neurologic signs, and generalized weakness. For these reasons, it is important to take your dog to the vet at the first signs.

How Does A Dog Act With Lung Cancer?

Only two-thirds of dogs diagnosed with lung cancer show clinical signs. The clinical signs of lung cancer in dogs can be confused with those of other respiratory conditions. As a result, you may notice labored breathing, exercise intolerance, decreased appetite, coughing, weight loss, and lethargy.

How Long Can A Dog Live With Cancer In The Lungs?

If the lung cancer is detected in its early stages and the tumor is successfully removed through surgery, your dog's life expectancy can be 1-2 years. However, if the cancer is in an advanced stage or if no treatment is provided, the life expectancy may decrease to approximately 2 months.

What Can Be Mistaken For Lung Cancer In Dogs?

Some respiratory conditions in dogs have clinical signs similar to lung cancer. Some examples include respiratory infections, heartworms, lungworms, pneumonia, or tracheal collapse. For this reason, it is advisable not to ignore the clinical signs that occur because your dog may be suffering from a more serious illness.

Should I Treat My 13-year-old Dog For Cancer?

A dog's age should not influence their treatment for cancer. If the dog's overall health is good, treatment should be considered. A dog with a strong immune system will be better able to respond positively to cancer treatments.

How To Comfort A Dog With Lung Cancer?

If your dog has been diagnosed with lung cancer, you can help by offering a balanced and nutritious diet, managing their pain with medication, ensuring they stay hydrated, providing comfortable and quiet resting spots, and considering symptomatic treatments along with natural supplements like PIPTOPET, SHIITAKE, and TONICPET#4, #5, #7, and #10 from Zumalka.

How Is Primary Lung Cancer Treated In Dogs?

The treatment of choice for lung cancer in dogs is surgical removal of the tumor. In cases where the tumor cannot be removed, your veterinarian may recommend radiotherapy or chemotherapy (for certain types of lung cancer). If the cancer treatment cannot be performed for various reasons, your veterinarian may recommend symptomatic treatment to improve your dog's well-being.

What Mimics Lung Cancer In Dogs?

Some respiratory conditions can mimic lung cancer in dogs. These may include chronic inflammation of the lungs, heartworms, lungworms, pneumonia, and tracheal collapse. It is important to seek expert advice if your dog exhibits signs of a respiratory condition.

About the author

Dr. Iuliana Mihai, DVM, MSc, PhD

Iuliana Mihai, DVM, MSc, PhD, is a Bucharest-based veterinary expert specializing in internal medicine and oncology.

Her work has been published in reputable publications such as Veterinary Medicine Journal, Catster.com, Dogster.com, Hepper.com, Meowiz.com, Springnaturals.com, Petkeen.com, and Wilderharrier.com.

She is a malpractice and negligence veterinary consultant and a graduate of The University of Agronomic Sciences and Veterinary Medicine and The Romanian Academy.

Read the complete profile of Dr. Iuliana Mihai, DVM, MSc, PhD (Veterinarian) here.