Help! My Dog Has A Mouth Lump

Updated November 28, 2020

‘Essential facts (Details Below)’

When A Dog Has A Mouth Lump

  1. Oral masses have a high probability of being serious
  2. The sooner they are biopsied, the better the chances
  3. But don’t panic: many still turn out to be benign

Now dive deeper…

If you bring your dog to the vet for a lump in the mouth. you might get a surprise. Your vet’s relaxed, ‘let’s keep this under observation’ attitude is likely to change.

We’ve all seen too many dogs die of oral cancer. So although it might be benign, take your vet’s advice if they ask you to act quickly. Mouth lumps can be very, very nasty.

The Common Oral Lumps

Good news first. The most common mass is the least harmful.


Epulis (pronounced eh-pooliss) is the most common lump in the mouth of dogs. It’s a benign overgrowth of the gums, not involving the bone. It usually looks just like the pictures above or below.

bleeding lump dog mouth

We see epulides a lot in older dogs, especially with bad periodontal disease. And Boxers. Have a look in any older Boxer’s mouth and you should see plenty.

An epulis can still be harmful though:

  • It can cover the tooth and trap food, causing tooth loss
  • It can get big enough to interfere with chewing
  • It can be something nasty that gets called an epulis by mistake

The dog pictured above is a good example. Ted is young, has excellent dental care (raw bones!) and isn’t a typical breed. Therefore, I biopsied this mass for analysis and it turned out it wasn’t an epulis at all! See what it really was later.

Papilloma or Wart

dog tongue wart

Young dogs that socialise a lot often pick up papillomavirus and end up with warts on the head and in the mouth. Here’s a good example. The clue should be finding others elsewhere and the history. In this case, it was solitary so I biopsied it to be sure.

The one below has a more classic appearance.

dog wart in mouth

The Nastier Oral Masses

Next most likely are the ones we fear. These are especially common in older dogs. Early on they can just look like the picture at the start. However, they invade bone quickly.

Below are the results of attempting to surgically remove these lumps. As you can see, getting an accurate identification is the key to knowing what to do. Melanoma and osteosarcoma are usually not curable. Ameloblastoma, which often looks the same, has an excellent outlook. That’s why we will start with a biopsy, where we send a small piece away for analysis.

TumourPrevalence% Survival at 1 year
Squamous cell carcinoma17%91%

* also called an ameloblastic fibro-odontoma or acanthomatous epulis

Ted’s tumour, by the way, was an ameloblastoma. It has an excellent prognosis but needs extra surgery to remove it completely. The speed with which his owners got him checked means that it shouldn’t be too disfiguring.

dog palate lump

There are many other, rarer tumours of the mouth of dogs, too numerous to mention. However, I’ve included all the examples seen over a 25 year career.

Pictured is also the incisive papilla found on a dog’s hard palate just behind the upper incisors- this is normal.

Surgery For Oral Tumours

If the prognosis is good enough, we will recommend you to see a specialist surgeon. Removal usually also involves some of the jaw, but you’d be surprised how well they do afterwards.

There is no doubt that the chances of survival for any of these tumours will go up the earlier they are treated.

So if you see a lump, should you be like Ted’s owner? He could have ended up with a result that says there’s nothing to worry about. That might seem like a waste of money.

It wasn’t. Early intervention has made his lump curable. If we’d waited, that could have no longer been true.

You might also like: Common Skin Lumps Of Dogs

Have something to add? Comments are welcome below and will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These help topics are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story! The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.


10 Replies to “Help! My Dog Has A Mouth Lump”

  1. I found a lump on my dogs gum, just above his first molar. It looked like a blister at first, but each day it was changing. I definitely thought it was just a tooth or gum boil and took him to the vet within a week, with the intention of getting the “dental” problem fixed. Turned out it was a highly malignant melanoma, and if i hadn’t found it he could have died within 60 days. He had it removed immediately, and then 6 months of chemotherapy. So I advice always have them checked out.

  2. 7 month old American Great Dane has two puffy smooth flesh colored growths on palate by back tooth. It is pink just like his mouth and then black looking just like his mouth tissue with a smooth appearance. It does not look inflamed or as a swelling would. It gets smaller and goes to the throat after the two bump areas. He will have a biopsy in 8/25. I am hoping because it has such a normal appearance that it will be ok. My daughter, who owns the dog, has bile duct cancer and worries he has cancer too. Of course your thoughts always go to the worst possibility. Does this sound really worrying?

    1. Hi Lori. You’re doing the right thing in getting a biopsy, and that gives me the opportunity to say that in the meantime don’t be too worried, as it’s unlikely to be serious.

  3. Our dog has a small pinkness in colour lump between his teeth top jaw it’s firm to touch and he doesn’t have any problems eating or drinking he had one of these about 2 years ago and the vet removed it he’s now 5 yrs old what can we do to treat it I’ve seen mouth wash or salted water tee tree oil would like your advice please

    1. Hi Stephen. None of the treatments you mention are likely to work. At this stage, a lump is usually best removed as it’s likely to get very large in your dogs lifetime

  4. My puppy has a quite hard incisive papilla, it actually looks like a tooth, and it’s kinda pointy! I also think it bothers him because his food is constantly getting stuck to the roof of his mouth and I has a hard time swallowing. Is there anything I can do to help him with this? And the article is very helpful cause I really thought my pup was an alien!

    1. Hi Doni. All you can do is choose food types to avoid this- kibble should be better than wet for example. However, I have never seen problems.

  5. This was so helpful. My older dog 17 yrs old has a round mass inside her mouth. It looks like a cherry tomato. By reading this I completely understand. The funny thing is that does not interfere with get eating. She never misses a meal but I have to say that her teeth on the side where the cherry tomato resides gets infected and messes with get eyes. I can’t afford a vet so I am glad o read this and help her a lot more. She isn’t any pain and still jumps around like a puppy.

    1. You clearly didnt read the article. Be ajse it says to get it checked asap to avoid pain, discomfort, having it grow and possibly cause jaw removal. Get your pup to a vet. Unless you’re already prepared to lose her.

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