Mouth Cancer In Dogs: Symptoms, Diagnosis & Treatment Options (2023)

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Just like people, dogs can develop growths in their mouths. These are called oral tumors, accounting for 6-7% of all dog cancers. Oral cancer in dogs is usually primary, meaning it arises directly from the mouth’s tissues. Some are benign but can be pesky, whereas some are malignant and need to be tackled quickly and aggressively.

Mouth Cancer In Dogs: Symptoms, Diagnosis & Treatment Options (1)

Table Of Contents

  1. What Are The Symptoms Of Mouth Cancer In Dogs?
  2. Oral Cancer Diagnosis
  3. Dog Mouth Cancer Stages
  4. Most Common Types Of Mouth Cancer In Dogs
    • Odontogenic Tumors
    • Non-Odontogenic Tumors
  5. FAQ About Oral Growths In Dogs
    • What About Viral Papillomas?
    • What Can I Do To Prevent My Dog From Getting Oral Cancer?
    • How Do I Know When It’s Time To Say Goodbye To My Dog With Incurable Mouth Cancer?
  6. Keep Your Dog’s Mouth Smiling
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What Are The Symptoms Of Mouth Cancer In Dogs?

The symptoms of oral cancer in dogs are usually directly related to where the tumor is growing and how big it is. For instance, dog lip cancer might be easy to spot, but dog gum cancer, or a growth deeper inside the mouth, can be harder to spot until it causes problems, such as impairing chewing or swallowing.

Therefore, many dogs with oral cancer have no symptoms for a while, and the tumor is picked up accidentally by the owner or the vet. In other cases, there can be symptoms, such as new or excessive drooling, bad breath, bleeding from the mouth (or occasionally the nose), swelling or deformity of the face, and difficulty eating, chewing, or fetching.

Before we get into the nitty-gritty of the different types of mouth cancer in dogs, it can be helpful to talk about how these cancers are diagnosed and staged.

Oral Cancer Diagnosis

The gold standard for diagnosing oral cancer is histopathology. This means obtaining a fairly large tissue sample of the growth (biopsy) under deep sedation or general anesthesia and sending it off to be examined by a pathologist.

While it may be tempting to just cut to the chase and have the mass surgically removed and sent off, taking the extra step to get the sample before surgery can make a massive difference in how successfully the cancer is treated down the line.

Dog Mouth Cancer Stages

Any tumor in a dog’s mouth has the potential to spread, either to surrounding tissues or to the rest of the body (metastasis). Therefore, the entire patient should be checked for tumor spread before surgery, which can drastically affect treatment decisions. This is called staging.

Nowadays, with CT scans (computed tomography scans) becoming more accessible, this is often the preferred route, along with the aspiration of the local lymph nodes. A CT scan allows precise visualization of the primary tumor and its invasion of local tissues. It also helps visualize the local lymph nodes, the lungs, and other organs in one go. Alternatively to a CT, head and chest X-rays can provide some helpful staging information but won’t be as precise.

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Once this information is gathered, the tumor is given a stage from 1 to 4 based on how far it has spread.

Most Common Types Of Mouth Cancer In Dogs

Oral tumors are usually separated into two broad categories based on whether the growth arises from tooth-forming tissues (odontogenic tumors) or not (non-odontogenic tumors). We now go over the most common ones, how they can be treated, and dog mouth cancer life expectancy without treatment or with treatment.

Odontogenic Tumors

Odontogenic tumors, or epulis, account for approximately 20-30% of all mouth cancer in dogs. They tend to arise from the tooth ligament and can look like dog gum cancer. Odontogenic growths are usually benign and don’t metastasize. Some are not cancer at all but an inflammatory reaction of the gum. This being said, certain types (called acanthomatous) can behave differently and be locally aggressive, invading the jaw bone or the nose, for example.

Dogs prone to epulis tend to be middle-aged or older. Predisposed breeds are those with a flat nose (brachycephalic), such as Bulldogs and Boxers, as well as Golden Retrievers, Akitas, Shetland Sheepdogs, and American Cocker Spaniels.

Epulis is often managed successfully by surgical removal, some requiring a more aggressive approach than others. This being said, radiation therapy is becoming more and more common to treat them as well and seems to generally have a tremendous success rate even with the more aggressive types.

Non-Odontogenic Tumors

Non-odontogenic tumors emerge from non-dental tissue. They are more common than epulis-type tumors and are sadly usually more severe. There are three main types: malignant melanomas, squamous cell carcinomas (SCC), and fibrosarcoma.


Mouth Cancer In Dogs: Symptoms, Diagnosis & Treatment Options (2)

Melanomas are the most common mouth cancer in dogs. They can arise from most parts of the mouth: gums, the roof of the mouth, lips, or tongue. Small-breed, older, dark-colored dogs such as black Cocker spaniels, Scottish Terriers, Poodles, and Daschunds are more prone. The tumors are often pigmented and black, but as many as 40% are not, which can be very misleading for the vet and even the pathologist looking at the biopsies.

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Melanomas are nasty tumors that are usually malignant, locally invasive, and many have already metastasized by the time they’re found. If this is the case, most dogs will not survive past a few months, no matter what is done.

If they are caught early, they can be treated with surgery and radiotherapy. Life expectancy is very case-dependent and usually ranges from a few months to a few years, depending on the stage and size of the tumor.

Squamous Cell Carcinomas

Squamous cell carcinomas (SCCs) are the second most common type of mouth cancer in dogs and the most common tongue cancer. They tend to arise from the gums or sometimes from a tonsil or the top of the tongue.

SCCs are typically invasive locally and can metastasize to the lungs in over 30% of cases. They can look like a cauliflower, an ulcerated mass, or a non-healing mouth sore. Middle-aged dogs are typically affected, though the tonsil form is usually seen in older dogs.

For SCCs arising from the gums or the tongue, removing part of the jaw or tongue can be curative or significantly slow the cancerous process, with 90-100% of dogs surviving one year, 80% surviving two years, and 60% surviving three years. The longest survival rates are achieved with surgery and chemotherapy.


Fibrosarcomas are the third most common type of mouth cancer in dogs and are usually smooth, rounded, pink tumors that arise from the gums, roof of the mouth, inside of the cheeks, or inside of the lips. They are most common in middle-aged, medium-to-large breed dogs.

These tumors can be quite large when finally discovered and tend to be locally invasive but rarely metastasize to the lungs. They are usually managed with surgery, which can be curative if the tumor is completely removed. If this is not possible because of the location of the tumor, then radiation can be added on.

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The prognosis with a fibrosarcoma greatly depends on its size and location, how completely it can be removed, and how aggressively it is behaving. In some studies, the average survival post-surgery was about two years, with dogs treated with surgery and radiotherapy seeming to have the longest survival times. And as mentioned above, surgery can be completely curative as well. Chemotherapy is not usually thought to be helpful.

FAQ About Oral Growths In Dogs

What About Viral Papillomas?

Some viruses can cause warts to grow around a dog’s mouth, on their lips, gums, and muzzle. These are called viral papilloma, which are usually harmless and go away on their own. They overwhelmingly affect puppies and young dogs, and though they are contagious between dogs, they do not affect people or other animals. Make sure you still have your vet have a look, though, especially if your dog is not a puppy.

What Can I Do To Prevent My Dog From Getting Oral Cancer?

While nothing can be done to prevent oral cancer in dogs, spotting it early can make a massive difference in the outcome. If your dog allows it, you should regularly conduct a thorough inspection of your dog’s mouth. Look over the inside and outside of the gums, lips, and cheeks, and look at the tongue and under the tongue. Brush your dog’s teeth, pay attention to any bad breath you notice or excess drooling, and maintain overall good dental care to catch anything unusual early on.

How Do I Know When It’s Time To Say Goodbye To My Dog With Incurable Mouth Cancer?

Preparing to say goodbye to our furry companions is often grief in itself, and many of us owners wonder if we know when the time has come. With dog mouth cancer, when is the right time to put them down? In many cases, an owner knows when their companion is no longer enjoying life as much as they should. Keep the dialogue open with your vet, but as a rule of thumb, as long as your dog is free of distressing sensations (be it pain, nausea, or difficulty breathing), enjoys its food, and gets around with ease, especially to use the toilet, then it’s ok to spoil them rotten and enjoy the time left together.

Keep Your Dog’s Mouth Smiling

Though there are other types of oral cancer in dogs, the ones covered in this article are by far the most common. The way these cancers are treated and the life expectancy after diagnosis and treatment greatly depends on the type of cancer, how quickly it was found, whether it has already spread, and how successfully it can be eradicated with or without surgery, radiotherapy, or chemotherapy.

Diagnostic tests, procedures, and cancer treatment can easily cause a substantial financial and emotional cost to pet parents. If you fear your dog may develop cancer (or another serious illness),investing inpet insurancecan help you get your pup the treatment they need for cancer without worrying about how you’re going to afford it.As long as you have a policy for your pet in place before they become ill, pet insurance providers can cover a portion of costs for diagnostics, medication, surgery, radiation, and other treatments.

Tagged With: Cancer

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What is the life expectancy of a dog with oral cancer? ›

Sadly, dogs who are diagnosed in later stages may only live for another 6 months to year. If not promptly treated, the prognosis for dogs with oral cancer is very poor. On average, there is a survival time of only 65 days.

How do you know if your dog has mouth cancer? ›

In dog's, the most common signs of oral cancer include: bad breath, excessive drooling, bleeding from the mouth, trouble chewing, obvious signs of oral pain, loose teeth, visible lump or mass inside of the mouth, swollen areas of the face, reluctance to eat and weight loss.

How is dog mouth cancer treated? ›

Surgery is generally the best treatment for oral cancer in dogs. If the cancer is caught early and the tumor is easily accessible for your vet, surgery could even cure your pup. For some dogs though, surgery may require the removal of a large portion of their jaw to get the most cancer cells possible.

What is the most effective treatment for malignant oral tumors in dogs? ›

Surgical removal is the most common recommendation to treat oral tumors. CT scans of the head/neck are usually performed prior to surgery to determine the extent of disease, as well as for surgical planning. If local lymph nodes are affected, they may be removed at the same time as tumor removal.

How fast does oral cancer spread? ›

There aren't any hard and fast timelines for whether or when oral cancer will spread. Size is more a determinant. For a moderate-sized oral cancer, there is roughly a 20 to 30 percent chance that it has already spread to the lymph nodes at the time of diagnosis.

When is it time to euthanize a dog with oral cancer? ›

A loss of appetite is a common sign that a cancer patient is declining. This can be a sign that their mouth is in too much pain to willingly eat food, but they may be feeling unwell overall. If you can no longer get your dog to eat, this could be their way of telling you they are ready.

Is mouth cancer painful for dogs? ›

Pets with oral tumors will often have a history of pain while trying to chew or swallow food, food dropping out of the mouth while eating, drooling, or not willing to eat at all. Periodontal disease, bad breath, and tooth loss may also be noted. If lesions are ulcerated, there may be blood-tinged saliva.

What does mouth cancer look like when it first starts? ›

Oral cancer can present itself in many different ways, which could include: a lip or mouth sore that doesn't heal, a white or reddish patch on the inside of your mouth, loose teeth, a growth or lump inside your mouth, mouth pain, ear pain, and difficulty or pain while swallowing, opening your mouth or chewing.

How long do dogs live with oral melanoma? ›

Prognosis. The average survival time of untreated dogs is reported to be 65 days. With surgery alone, the average survival times and 1-year survival rates of dogs range from 5-17 months and 21-27%, respectively. In general, the smaller the tumor and the closer to the front of the mouth it is, the better the prognosis.

What do you feed a dog with mouth cancer? ›

While additional research is needed, it is recommended that canine cancer patients eat a ration with 25-40% DM fat and 5% DM or greater of dietary omega-3 fatty acids.

Can oral cancer be cured without treatment? ›

If the cancer has not spread beyond the mouth or the part of your throat at the back of your mouth (oropharynx) a complete cure may be possible using surgery alone. If the cancer is large or has spread to your neck, a combination of surgery, radiotherapy and chemotherapy may be needed.

What percentage of oral tumors in dogs are cancerous? ›

In another more recent study of oral tumors, 50 dogs (74.6%) had a malignant neoplasm and 10 dogs (14.9%) had a benign neoplasm [14]. In this study 962 cases (53.6%) of canine oral tumors were classified as malignant and 455 cases were classified as benign (25.4%).

How much does it cost to remove a tumor from a dogs mouth? ›

Cost of Surgical Tumor Removal in Dogs

For a simple skin tumor removal, the cost can vary from $180 to 375, whilst more complex internal tumors run $1,000- $2,000 and upward. Costs vary depending on the surgical time and the complexity of the surgery.

What is the most common malignant oral tumor in the dog? ›

In dogs, the three most common malignant oral tumors are malignant melanoma, squamous cell carcinoma, and fibrosarcoma.

Which is the most common oral tumor in dogs? ›

Oral melanoma is the most common tumor of the oral cavity of dogs. They are most common in older dogs over 10 years age. Melanomas originating in the mouth are uniformly malignant. They are locally invasive and have a moderate rate of spreading.

What are the signs that oral cancer has spread? ›

Advanced cancer means cancer that started in the mouth or oropharynx has spread to another part of the body.
Symptoms if cancer has spread to the lungs
  • a cough that doesn't go away.
  • shortness of breath.
  • ongoing chest infections.
  • weight loss.
  • chest pain.

What is the last stage of mouth cancer? ›

Stage IV is the most advanced stage of mouth cancer. It may be any size, but it has spread to: nearby tissue, such as the jaw or other parts of the oral cavity.

What are the stages of mouth cancer? ›

For oral cancer there are 5 stages – stage 0 followed by stages 1 to 4. Often the stages 1 to 4 are written as the Roman numerals I, II, III and IV. Generally, the higher the stage number, the more the cancer has spread. Talk to your doctor if you have questions about staging.

What to do if your dog has cancer and you can't afford treatment? ›

Check for state-specific financial assistance programs for pet healthcare. If there's no fund designed for your specific situation, RedRover's Urgent Care Grants might help. RedRover provides almost 700 grants every year for pets whose owners can't afford treatment, with an average grant amount of $200.

Do dogs know when they are dying of cancer? ›

She says it's tough to know how much a dog understands or is feeling near the end of their life, but some behaviors might be more apparent. "Many dogs appear to be more 'clingy' or attached, following you around consistently and remaining close," Bergeland says.

How do you comfort a dog with cancer? ›

Cancer. Palliative care for cancer in dogs focuses mainly on managing pain and making things as normal as possible for your dog right up until the end. A comfort care plan might combine prescription pain medications with nutritional supplements and other therapies such as massage or acupuncture.

Does cancer spread quickly in dogs? ›

⁵ Large breeds of dogs, like poodles, are very susceptible to bone cancers as they grow out of puppyhood. This kind of cancer can be very aggressive, spreading quickly throughout the body.

Does mouth cancer progress quickly? ›

Most oral cancers are a type called squamous cell carcinoma. These cancers tend to spread quickly.

Where does mouth cancer usually start? ›

Mouth cancer, also known as oral cancer or cancer of the oral cavity, is often used to describe a number of cancers that start in the region of the mouth. These most commonly occur on the lips, tongue and floor of the mouth but can also start in the cheeks, gums, roof of the mouth, tonsils and salivary glands.

What Colour is mouth cancer? ›

Mouth cancer can develop on most parts of the mouth, including the lips, gums and occasionally, the throat. The most common symptoms of mouth cancer include: red or white patches in the mouth or throat.

What does melanoma look like in a dog's mouth? ›

Melanoma tumors can be pigmented (black) or non-pigmented (pink/flesh colored). Dogs can show increased salivation/drooling, difficulty eating/drinking, drop their food or chew on only one side of their mouth. They may show facial swelling and/or have a foul odor to their breath.

How aggressive is oral melanoma in dogs? ›

Most melanomas are diagnosed in older dogs with the average age being 11 years of age. Oral melanoma is an aggressive cancer that can metastasize (spread) in up to 80% of cases to the regional lymph nodes and lungs. These tumors are often pigmented, but there are some tumors that lack pigment (amelanotic).

Can oral melanoma in dogs be cured? ›

The good news: oral melanoma can be treated. The bad news: complete removal of the cancer is difficult and many times part of the dog's jaw has to be removed. Tumor recurrence and metastasis is common with malignant oral tumors.

What foods should dogs with cancer avoid? ›

It is very important to avoid feeding raw diets or treats to pets with cancer! Raw meat, eggs, and milk carry high risk of bacterial contamination with Salmonella, Listeria, E. coli, Campylobacter, and other potentially dangerous bacteria. Freezing or freeze-drying do not make raw diets safe.

Is it worth putting a dog through chemotherapy? ›

Indeed, early detection can help with treatment, recovery, and prolonging your dog's quality of life. Cancer is unfortunately often incurable in dogs. In these cases, chemo may still be recommended as a way to help ease your pet's symptoms resulting from the disease.

How can I fight my dogs cancer naturally? ›

And hempseed oil has been shown to reduce metastasis and cancer growth in brain, breast and lung cancer. Hemp seed also contains plenty of vital minerals like manganese and zinc, making it a healthy addition to any diet. To give your dog hemp seed, you can grind it fresh or buy it as an oil.

How do you slow down oral cancer? ›

The most important is not to use any tobacco. It is also important not to drink too much alcohol or to abstain from alcohol altogether. A very simple thing that everyone can do that will decrease the risk of oral cancer is increase fruit and vegetable consumption.

What happens if mouth cancer is not treated? ›

Left untreated, oral cancer can spread throughout your mouth and throat to other areas of your head and neck. Approximately 63% of people with oral cavity cancer are alive five years after diagnosis.

How often is oral cancer fatal? ›

For all mouth (oral cavity) cancers:

more than 75 out of 100 people (more than 75%) survive their cancer for 1 year or more after they are diagnosed. around 55 out of 100 people (around 55%) survive their cancer for 5 years or more after diagnosis.

Can oral tumors in dogs be cured? ›

Surgery is often the treatment of choice for dog mouth cancer, but it may not lead to a cure because the tumor often has already spread to other parts of the body. A large amount of bone and tissue surrounding the tumor may also have to be removed to eliminate the majority of cancerous cells at the site.

Are all growths in dogs mouth cancerous? ›

An oral mass refers to a growth in a dog's mouth or surrounding head region. While not all growths (masses) are cancerous, oral tumors can become malignant and fatal if they are not treated early and aggressively. Oral tumors can be found in the dog's lips, tongue, gums and lymph regions surrounding the mouth.

How do you tell if a tumor on a dog is malignant? ›

How to Spot Cancerous Lumps in Dogs
  1. Large Lumps. ...
  2. Sudden Appearance of Lumps. ...
  3. Changes in Size, Colour and Texture. ...
  4. Discharge from Lumps, the Nose or the Eyes. ...
  5. Sores and Wounds that Won't Heal. ...
  6. Significant Weight Loss. ...
  7. Chronic Vomiting or Diarrhoea. ...
  8. Weakness and Lethargy.

What does a tumor on a dogs gum look like? ›

What does an epulis in dogs look like? An epulis in a dog can look smooth or have a cobblestone appearance. It can grow in a mound or as a stalk, and is often the same color as the gums.

What happens if you don't remove a mast cell tumor from a dog? ›

Mast cell tumors are quite serious when identified in dogs. If untreated they can cause anaphylactic shock or if they progress into a more aggressive form they can metastasize and ultimately lead to death.

Can a tumor in a dogs mouth be benign? ›

The diagnosis of an oral mass in a pet can be a frightening thing for a pet owner. However, the majority of oral tumors in dogs tend to be benign, meaning they are often less aggressive and do not spread to other regions of the body like a malignancy.

How long can a dog live with an oral tumor? ›

Sadly, dogs who are diagnosed in later stages may only live for another 6 months to year. If not promptly treated, the prognosis for dogs with oral cancer is very poor. On average, there is a survival time of only 65 days.

What does a cancerous tumor look like in a dog's mouth? ›

Melanomas appear pigmented or non-pigmented, and may be nodular or cauliflower-like in appearance. These tumors may appear as swellings on the gums around the teeth or on the hard or soft palates. They frequently ulcerate (break open) and bleed. They may also become infected.

What causes tumors in dogs mouths? ›

In most cases it's not possible to determine the cause. However, a variety of genetic and environmental risk factors are typically at the root of mouth cancers in dogs. Breeds with a somewhat elevated risk of developing the disease seem to include weimaraners, German shepherds, boxers, chows, and miniature poodles.

What percentage of oral tumors are benign? ›

About 80% are benign.

How Long Can dogs live with oral melanoma? ›

The average survival time of untreated dogs is reported to be 65 days. With surgery alone, the average survival times and 1-year survival rates of dogs range from 5-17 months and 21-27%, respectively. In general, the smaller the tumor and the closer to the front of the mouth it is, the better the prognosis.

What is the prognosis for stage 4 oral cancer? ›

Survival at 5 years

Survival can vary from 95% at five years for stage 1 mouth cancer to 5% at five years for some cancers at stage 4 disease, depending on the location of the lesion.

What is the fastest spreading cancer in dogs? ›

Updated June 16, 2022 – Hemangiosarcoma is a common and deadly cancer of dogs. The cancer tends to grow and spread rapidly, rarely giving the owner any clue their dog is harboring a deadly disease – until it suddenly strikes.

How does oral melanoma progress in dogs? ›

If the tumor spreads to lymph nodes, there can be swelling under the jaw or along the neck. If it spreads to lungs, pets can show signs of lethargy, inappetence and difficulty breathing. Some dogs show no signs, and a tumor is discovered during a routine exam or dental cleaning.

Is oral melanoma painful in dogs? ›

These tumors may look small from the outside but extend deeper into the tissues than expected, invading the underlying bone. Alternately, the bone may be affected first causing significant oral swelling. Oral pain is usually apparent, especially in dogs with tumors that have penetrated the underlying bone.

What are the symptoms of last stage of mouth cancer? ›

  • A lip or mouth sore that doesn't heal.
  • A white or reddish patch on the inside of your mouth.
  • Loose teeth.
  • A growth or lump inside your mouth.
  • Mouth pain.
  • Ear pain.
  • Difficult or painful swallowing.
26 Oct 2022

How much does it cost to remove a tumor from a dog's mouth? ›

Cost of Surgical Tumor Removal in Dogs

For a simple skin tumor removal, the cost can vary from $180 to 375, whilst more complex internal tumors run $1,000- $2,000 and upward. Costs vary depending on the surgical time and the complexity of the surgery.

Can canine oral melanoma be cured? ›

The good news: oral melanoma can be treated. The bad news: complete removal of the cancer is difficult and many times part of the dog's jaw has to be removed. Tumor recurrence and metastasis is common with malignant oral tumors.


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