Lung Cancer in Dogs: General Symptoms And Types of Carcinoma

Lung cancer dog X Ray
Wyatt Robinson
Written by Wyatt Robinson

Cancer is not a sickness that only occurs in humans. Unfortunately it is one of the most frequently met types of carcinoma in dogs older than 7 years, along with cardiovascular diseases. When it comes to lung cancer in dogs, the chances of recovery are not encouraging, but there are ways to improve a dog’s general condition and make what is left of its life as pleasant as possible.

In order to ensure a favorable outcome in the fight against cancer, a dog’s owner should pay attention to different signs and symptoms and identify them as soon as they appear. Any sickness that is discovered in its early stages can go into remission. However, if your dog is already in the metastasis phase, there is still hope. The treatments available for dogs are similar with the ones applied for people, namely chemotherapy, radiography and surgery. The surviving rates depend on multiple factors.

General cancer symptoms in dogs

Dogs can get the same types of cancer as people. Although there are particular symptoms for every type of cancer, there are a few general ones that can be easily noticed by a dog owner who pays attention to his or her dog’s everyday behavior. Some of these symptoms might not make you think of cancer, but if they’re present, a specialist should take an in-depth look at your beloved pooch before things get complicated and most probably incurable. As it follows, there are 11 signs that could predict the presence of tumors in your dog’s fragile body.

Cancer signs in dogs

Swelling and various skin lesions: Not all of these changes are likely to be cancerous, but if you find that they are painful for your canine pet and have a rapid growing rate, it is advisable to consult a specialist in oncology. If you don’t know who to turn to, the vet you see regularly can point you in the right direction.

To learn know what to look for, you should definitely check out this article on tumors in dogs.

Abnormal odor: Any uncharacteristic odor or a repulsive odor that comes from your dog’s skin, nose, mouth or ears can indicate the formation of a tumor. This is not necessarily a case of cancer, but it is a sign that you shouldn’t ignore. Even if it is just a common infection, going to the vet will avoid complications.

Vomiting, diarrhea, different discharges: The emergence of symptoms such as vomiting, diarrhea, bloody or purulent discharges or other liquids should determine you to take your pooch to the vet. Any kind of changes occurred at abdominal level should not be ignored either.

Slow healing: Wounds that heal slowly can also be a sign of cancer. The dog’s immune system might not work properly anymore because of carcinoma, therefore its other lesions would heal slowly because it is already overwhelmed trying to fight the other harmful changes that take place in its body.

Weight loss: A dog that loses weight all of the sudden could be sick. Weight loss represents one of the main symptoms of cancer and the main reason why dog owners go see the vet immediately besides situations when the cancer is visible thanks to mammary tumors, vaginal tumors or skin formations. A sick dog doesn’t stop eating, but it still loses a lot of weight.

Loss of appetite: Such symptom indicates a malaise of your canine pet. Behavioral changes of this kind only appear if there are others present as well, such as nausea, tumors in its oral cavity that cause pain or difficulty chewing or swallowing and abdominal pain.

Cough: Coughing and difficulty in breathing are concerning causes as well. Cancer is not the only possible diagnosis in this situation either, but the risk of postponing a visit to the veterinarian to investigate this problem further is too high to take on you. This could be the case of a primary lung tumor or a lung tumor’s metastasis. 25% of dogs have no lung cancer symptoms until it is detected by an X-ray.

Limping: As curious as this may sound, a limping dog could be a dog with lung cancer. This type of cancer can make a dog’s leg bones grow new tissue, causing swelling and pain in its legs. These changes usually disappear when cancer treatment is administered.

Lethargy: This is a radical behavioral change. If your dog goes from being cheerful and active to depressive and inactive, you should take the change seriously. It is an important symptom that indicates a malaise felt by your dog’s body.

Urine and feces changes: Traces of blood, pus or mucus in a dog’s feces or urine are bad signs. These can indicate the presence of formations inside its digestive tract or bladder. If you don’t pay attention to these aspects, you should start doing so now.

Pain: If your canine pet starts crying, crouching, hiding or limping, it might be because there are tumors forming inside its body and it doesn’t know how to handle them. These cases need the intervention of a specialist as well.

Types of lung carcinoma in dogs

Lung adenocarcinoma and squamous cell carcinoma of the lung are the two types of lung cancer that dogs can get. The difference between them is that the first one affects much more dogs than the second one. The squamous cell carcinoma of the lung is considered to be a rare case of lung cancer and it is way more harmful than the first one.

A dog affected by the second type of cancer skips a few phases and it can be diagnosed only after making a biopsy of the lung tissue, process which can be quite unpleasant for both the dog and its owner. In addition, if not treated, this form leads to death in approximately 3 months from its occurrence.

Lung adenocarcinoma in dogs

Lung adenocarcinoma is the type of lung cancer that affects dogs in proportion of 75%. It is a malignant tumor that can develop quickly and metastasize to distant parts of a dog’s body including organs, lymph nodes, bone, brain and eyes. Just as any other malignant tumor, lung adenocarcinoma usually occurs in dogs older than 7 years. Any dog breed can be affected by this type of carcinoma, but studies have shown that Boxers are more at risk when it comes to developing lung cancer.

As for the symptoms, they are mostly related to the respiratory system, but it case of metastasis, symptoms may vary depending on location. Metastasis is a term that refers to the spread of the sick cells.

Symptoms and causes: Among the symptoms of lung adenocarcinoma in dogs are: pain, dyspnea that means difficulty in breathing, tachypnea that means rapid breathing, low energy levels, lethargy, decreased appetite, gradual weight loss, hemoptysis that means coughing up blood, limping in cases with bone metastases, muscle wasting, fever, ascites that means fluid accumulation in the peritoneal cavity of the abdomen.

In case of a dog with a tumor, not all these symptoms must be present. The exact cause of this carcinoma type is still unknown. However, the risk factors are residence in an urban environment and passive inhalation of cigarette smoke.

Diagnosis: In order to establish a diagnosis, a veterinarian needs a complete history of your dog’s health, including background information about its symptoms. After performing a clinical examination, the specialist will most probably require different tests, including a complete blood profile and X-rays. The thoracic X-rays are the most important ones when it comes to putting the lung cancer diagnose.

However, an ultrasound, a computed tomography scan (CT) and a magnetic resonance imaging (MRI) could also be useful to confirm the diagnosis. A CT or an MRI can reveal the areas where the tumor spread or if it is in a spreading phase or not.

Treatment: After the diagnosis is clear, the sick doggy should be taken to an oncologist vet for treatment. There are 3 major procedures recommended in case of lung adenocarcinoma, which are surgery, radiotherapy and chemotherapy. The type of treatment or the combination of treatments is chosen based on factors such as size, location, the presence of metastasis, age and so on. There isn’t a treatment that applies to every pooch, so it must be personalized.

Surgery is usually chosen just to remove a tumor from the lung. Chemotherapy and radiotherapy are meant to improve the survival chances of a dog with lung cancer. The survival rates are not encouraging, but these procedures can buy your dog more time.

Squamous cell carcinoma of the lung in dogs

A squamous cell carcinoma of the lung is a type of tumor that occurs in lung metastases from the squamous epithelium. This is a rare type of primary tumor that has a high metastatic potential, especially if it reaches the regional lymph nodes.

In other words, a squamous epithelium is a type of epithelium that has flat, scale-like cells. The term epithelium refers to the cell coverage of all internal and external surfaces of both people and dogs bodies. It affects dogs in proportion of 25%, which means 3 times less than the lung adenocarcinoma. However, this is a severe form with very disappointing survival rates.

Symptoms: Among the symptoms of this cancer type are cough, lethargy, inability to exercise normally, weight loss, limping, increased breathing rate and coughing up blood. Remember that only some of these symptoms might be visible in your dog. The occurrence of all is not necessary in order to be sure that your beloved pet has serious problems. Any sign that doesn’t seem right should be enough for you to schedule an appointment with the vet. Waiting too long is never a good idea when the implications of such sickness are severe and sometimes even deadly.

Dog lying on the floor

Diagnosis: Just like in the case of lung adenocarcinoma, you must provide an accurate medical history of your pooch and present its symptoms along with the exact moment when they started to occur. A standard clinical exam includes routine laboratory tests with a complete blood count, a biochemical profile and urinalysis. The result of blood tests may reveal an increased number of white blood cells levels that are also known as leukocytosis levels, which are indicative of an invasion, determining the body to fight against it.

Biochemistry profiles in some patients may reveal abnormally high calcium levels. Besides these tests, a veterinarian can and probably will request an endoscopy. This procedure involves the insertion of a tubular device inside the dog’s body that takes samples of its lung tissue and fluids. Typically, the result of this test is enough to establish an initial diagnosis. X-rays are also necessary because they can reveal obstructions of the airways. However, the most conclusive test is a biopsy that is much more invasive than an endoscopy.

Treatment: Sadly, most canine patients will need surgery if they are affected by squamous cell carcinoma of the lung. Chemotherapy is also recommended by oncologists immediately after the diagnosis is clear. A complete resection of the affected lung lobe is often the only way to stop this highly metastatic cancer from spreading. Such an intervention will provide the best opportunity for long-term survival of the patient.

If lymph node involvement is suspected, a sample will be taken from there as well. If they lymph nodes are involved, the veterinarian can remove them to prevent the further dissemination of the cancer cells. In other words, there are few cases that don’t require surgery.

Sadly, this type of lung cancer is ruthless. A dog that doesn’t receive treatment might survive 3 months or less. However, even with treatment, the general survival time is not more than a few months. Sometimes trying to remove the tumor and putting your dog through chemotherapy might not have good enough results to be worth all the suffering. An oncologist can sincerely advise you to go further with the surgery and treatment or not.

Chemotherapy is highly toxic, has side effects and it might be too tormenting for your fragile canine friend to handle. Moreover, surgery weakens any living being’s body and it stops any dog from doing what it loves for as long as it still lives. Pain medications do work, but they can’t be administered for long periods of time.

If you’re looking for a more natural remedy, check out this article on the Prana Pets cancer treatment.

Passive smoking dogs get cancer

Dogs are victims of passive smoking because of their owners. They inhale the emanated cigarette smoke and swallow toxic substances that are deposited on their furs. This situation leads to the development of lymphoma, bronchitis and, ultimately, cancer. You can protect both your dog and yourself by giving up smoking. If you’re not motivated enough, maybe you will have an extra reason if knowing that cigarette smoke also affects your beloved pooch.

Cigarette smoke is bad for both your health and your dog’s health because it irritates the respiratory system and it carries a large number of toxic and carcinogenic substances in your body and in the bodies of everyone around you. In case you are not a smoker, but your friends are, try to keep your pooch away from them when they feed their vice.

Smoking dog

Dogs are often victims of passive smoking. They don’t only inhale toxic compounds and carcinogens such as polycyclic aromatic hydrocarbons and nitrosamines, but, in addition, they ingest harmful chemicals during their daily cleaning process. After repeated and prolonged exposure to cigarette smoke, a dog’s throat, trachea and bronchi become inflamed and it manifests by coughing that, in time, becomes painful and tiring.

Chronic bronchitis may extend to the lungs and the doggy may then develop pneumonia. In case of dogs, the toxic compounds contained by cigarettes are responsible for the occurrence of mouth, throat and lung cancer. Dogs with long noses such as collies and shepherds are at risk of getting cancer more than dogs with short noses. However, pugs are prone to developing lung cancer if they smoke passively.

Conclusions for healthy pooches

Dogs’ bodies might not function exactly like humans’ bodies, but unfortunately they can get sick just like humans. Cancer under any form is ruthless for any canine specimen. Some can be detected and treated, while some are too severe to be cured or to at least be led into remission. As a dog owner, your decision will count the most if you’ll have to accept a surgery or an invasive treatment for your dog. There are people who simply don’t want to go through endless sessions of chemotherapy and endure all the afferent side effects, but your dog won’t really have a say in this.

Dogs for the paws

Although it involves a lot of responsibility, having a dog with lung cancer should not feel like the end of the world. Different experiments are made every day and the available treatments are in a continuous change. Remember that your state of mind is reflected on your dog. It is such an empathetic being, that you can’t possibly hide this from it. Therefore, stay positive and avoid exposing your dog to factors that can trigger the formation of tumors in its adorable little body.

About the author
Wyatt Robinson
Wyatt Robinson

Wyatt Robinson had a great 25-years career as a veterinarian in United Kingdom. He used to be a member of British Veterinary Association and worked in 3 pet hospitals in London and Manchester. He is shining when he sees his pets healthy and full of energy and it is his duty to help other dog owners to keep their best friends full of life.