The cancer cats get in their mouths

I really couldn’t come up with a catchy title. It’s a sucky disease. Cancer sucks. So the title sucks. It’s a theme.

But let’s talk about Squamous Cell Carcinoma. It’s a type of cancer that can occur in a variety of places. Humans get it on their skin (reason to wear your sunblock!!). Dogs and cats can get this kind of cancer on their skin as well, but it is not very common, because they have fur for sunblock! Because the skin version is related to UV exposure (like our version) it tends to affect more light colored animals, and in areas with thin fur, like the nose, tips of ears, etc.

We’re talking about a different version of Squamous Cell Carcinoma. A much deadlier, suckier one.

This is the most common oral tumor of cats. If you find a cat with a mass growing anywhere in the mouth (lips, gums, palate, etc) we assume it is a squamous cell carcinoma until proven otherwise. If we wanted to 100% confirm it was this cancer, a biopsy of the growth under general anesthesia is the best way. Some vets will try to cut back the tumor (debulking) while they are at it, but this does not really improve the prognosis. This cancer does not tend to metastasize, or spread throughout the body, which is a good thing. So why do we hate it so much?

The tumor grows in the mouth and can invade the bones of the skull. We use the term “locally invasive” to indicate it does not spread throughout the body, but really can get out of hand in the area it is in. We hate this disease because it makes us euthanize a cat who is otherwise healthy. From the neck down, the cat is healthy and normal! But this awful tumor invades the mouth, preventing the cat from eating. We obviously don’t want the cat to starve to death, so humane euthanasia is eventually chosen as opposed to starvation.

cat tumor

In some lucky cats, the tumor grows on the bottom jaw, which we can surgically remove (yes, cats can live with a partial bottom jaw!). This is often best performed by a specialist, as it is a very involved procedure. When the tumor invades the upper jaw (the maxilla) that connects to the face, it can even effect the eye! Obviously, we can’t surgically remove half your cat’s face. I have had some owners pursue radiation therapy for these cats. Unfortunately, the eye is usually in the field of radiation, and may suffer because of it. But some of these tumors do shrink a little.

What about a feeding tube? If the whole cat is healthy, and it just can’t eat, can’t we do it for them? I have had a couple clients who could not let the cat go, and we did a feeding tube. It does not help significantly improve the quality of life of these cats. The tumor continues to grow, eating away at the skull. We have teeth falling out because the bone that holds them in is so abnormal. We have a cat drooling blood all the time, and they are generally very uncomfortable.

The most common symptom we see with oral squamous cell carcinoma is the breath. I often joke I can diagnose this disease simply by walking in the room. It is a smell like no other – a smell of rotting, decaying tissue. Sometimes the swelling in the face is apparent from across the room, while other times we have to open the mouth to look.

This disease sneaks up on people…how often do YOU look in your cat’s mouth? And if you are not keeping up on your cats dental care, you may just think it’s a bad tooth you’re smelling. Bloody drool is another common symptom, but again, people often blame dental disease (which the cat very well may have as well!).

So if you notice your cat’s breath smelling extra bad, get him to the vet! If caught early, and if they happen to grow in the right place, some of these tumors may be resectable. Otherwise, knowing what you are dealing with lets you focus on making your cats remaining weeks/months as good as possible.

Posted in Dental health, Feline specific.


  1. Thank you for writing this. I had to put my 16 year old cat down today, because of this very thing. I took her to the vet last week, as she started drooling and we all thought it was a tooth issue. (The vet didn’t check under her tongue.) I felt a lump the same day as her vet visit, but we all decided to look at it, once she was sedated. However we couldn’t do that yet, because she was diagnosed with a heart murmur and needed to check that out first. *she was also diagnosed with hyperthyroidisim this past week, after blood tests, but it was in the very early stages.

    I woke up this morning to her bleeding profusely from her mouth and it took two vet visits today to diagnose her. We didn’t need to wait for a biopsy – the lump I found under her chin – was actually a tumor that had grown from under her tongue and was about the size of a grape and hard.

    We made the decision to let her go today, rather than prolonging suffering on her part. There wasn’t any way to stop the bleeding and it was just going to keep growing.

    I couldn’t let her die in more pain – so I did what was easier for her. And reading this makes it a little easier to deal with the emptiness and pain I feel in my heart. She was everything to me and I hope I proved that, for ensuring she didn’t suffer and she left this world happy and in my arms.

    • Michelle, I just read you note. My cat was 14 and I had to let her go this past Monday. About 5 weeks ago we discovered a large sore under her tongue. We tried antibiotics in case it was just a canker sore. Within 2 weeks it had tripled in size so we did the biopsy. It was Squamous Cell Carcinoma. For a couple of weeks I thought she would get better then her mouth started bleeding and we found another tumor. It broke my heart to let her go but I could not watch her suffer. I’m sorry for your loss.

  2. This article has given some clarity for a very difficult situation. My Persian developed a lump that bled in August. After treating with a topical cream and antibiotics it has progressed. He also had a grade four heart murmur so I decided not to have him under go the biopsy. The specialist did feel it was cancer in his chin. It’s been five months now with daily pain medication. He is drooling blood; struggling to eat and does not clean himself anymore. My vet has performed progress visits and feels he if continues to eat there is quality of life.

    I have felt at a crossroads to prolong his life or make the decision to end it humanely before it progresses more. We have another vet visit this week; I hope the vet will help me make the ethical decision but I fear it will be more advice to continue to feed him at any cost.

    He isn’t the same cat and it breaks my heart to see him succumb to this disease.

  3. I found some comfort reading this article. It was very informative and helped me understand things more clearly. We just put down our 10/11 year old cat – Not sure of his exact age since we adopted him…His symptoms started with drooling & for a week we thought he had some sort of virus. He was eating & seemed his usual self so we did not go to the vet right away.
    At the first vet visit blood work was all normal. It was not until the second vet visit that the growth was discovered. An antibiotic shot & pain medication was given. We were hoping it maybe was a clogged saliva gland. By the third vet visit we were told the bad news.
    Our poor guy was trying to groom himself but he still looked a mess. Our vet said only the tip of his tongue was working & the rest of his tongue was hard like a rock. We never noticed any bad breath but the drool sometimes appreared pink on his bedding.
    About two weeks from the start of his symptoms he stopped eating. We could tell he wanted to eat but he could not. Really heartbreaking. That is when we knew he had to be put him down ASAP to end his suffering. We will miss the presence of the big guy very much.
    Looking back I do recall him sometimes looking like he was having a “difficult” /messy time chewing his hard foods compared to our two much younger cats. He was on the heavier side & was nourished so I just attributed it to him getting older perhaps aging teeth.

  4. Hi thank you to all who have posted, it gives me a small amount of comfort that I am doing the right thing for our big boy by making arrangements today to have our Teddy put to sleep, he has been drooling but still eating and appears otherwise normal, however vet has found a large mass on bottom jaw hence drooling constant and suggested we put him to sleep to save him any pain going forward.Vet was very adamant this is the only option.
    Hardest decision as he appears normal otherwise,

  5. So can my cat still eat with the surgery of getting the tumor removed? And can I give my cat medical marijuana to open and kill the tumor ?

  6. Kile, my cat had it. We removed it once but it came back with a vengeance. I had to let her go. The vet said we would have to remove most of her tongue and jaw and I would not do that to her. That is cruel. We have to know when to say good bye and let them have some dignity in death. It was he hardest thing I’ve ever done but I could not allow her to be cut up and live on pain meds. I’m sorry for your cat.

  7. My cat died last week. 01/24/2020. 13 years, 7 months and 4 days old.
    I was there when he was born.
    They didn’t let me stay with him in the ICU, so he died without me around 3 am.
    He actually went into shock earlier, it must’ve happened on the ride home from the Vet
    around 6:30pm.
    Infusions helped him a lot this month. I still need to go over the report from the ICU
    with his Vet, to better understand what “suddenly” happened, other than being doomed. Squamous Cell Carcinoma on his gum.
    My mom died of a cancer with the same name, but I’ve been said not to equate them.
    That was just last June. I remember when my aunt brought me home from the hospital one
    evening and we watched Azrael and I said “I don’t like how he eats, somethings up”.
    Our first trip to the Vet because of that was on July 1st. She missed it. I wanted to
    go to the other doctor that works at the same clinic, because I knew she was wrong, but
    that would’ve been a day before my moms funeral, so my little munchkin drew the short end of the stick. A few weeks later, my little baby bear was laying on my chest and I finally
    saw this lump just behind his teeth on the upper gum. Back to the same vet the next day
    and from then I went to four different clinics with him, had the mass partially removed
    on October 29th and tried “dendritic cell therapy”.
    Tough little fella endured everything and I’m thankful for this long warm summer and mild temperatures that went on almost until November. He had plenty of normal days,
    some really great days and I’m thankful for every time he hopped up to me on the couch
    and kneaded me bloody or put his paw in my face while cuddling.
    I regret so much though. The “what ifs” are torturing me and I’m envious of people with their
    older cats. In 20 minutes it will be a week that he is gone. I miss him so much.

  8. Did a biopsy on our 15 year old tabby, Rio. After nearly 2 weeks of tests and re-tests of that material, the results are inconclusive. The lab first said it tests positive for oral stomatitis but could be “atypical”, which could be stomatitis or cancer. So they tested other material from the biopsy and is still inconclusive but they say they “suspect” squamous carcinoma but did not outright confirm it and wants to take more biopsies. She is not drooling, no bleeding, but does have a rather large red area on her mid-left upper palette. She also tested positive for early hyperthyroid and is on meds for that. Should I have the doctors keep poking around? Or let Rio live whatever life she has left and just do the right thing when it comes time without all the additional testing?

    • @Joel I really, really hope that it’s not it. The results from the biopsy that you describe, or rather its interpretations, really mirrors what I’ve been through with Azrael. The first biopsy was a “fine needle aspiration”, which pointed to eosinophilic granuloma and signs of infection. Started treating him with antibiotics to combat the later. Even the more invasive biopsy was vague, for a laymen at least, and used the same vocabulary that you mention: “atypical and suspect”, but did include that with “high certainty the presence of a carcinoma” was given.
      I even had the biopsy re-evaluated again and went to yet another Vet in hope of it being something better treatable, non-fatal, to no avail.
      Azrael did not drool or bleed either at first. He ate sloppy and his breath got bad.
      The lump that you describe sounds horribly familiar, sadly.
      When they did Azrael’s biopsy they also made a CT scan of his head, ultrasound (he also
      had EPI) and xray. I don’t know why in Rio’s case the biopsy taken so far has not generated
      more substantial results. Treatment or palliative care of course depend on what exactly
      the ailment is. She might at least need pain meds, depending on how well she eats.
      Today marks the two week anniversary of my little babe being gone. That’s 7 month
      after I noticed something being up.
      In hindsight I really wish I had tried radiation therapy. It might’ve bought him up to year,
      but there aren’t many clinics that offer that around here and I really did not get along well
      with the oncologist. Maybe it was just that I didn’t hear from her what I was hoping for.
      This blog is great, searching the internet for “feline oral squamous cell carcinoma”
      will get you many more results.
      I wish you both the very best.

      • John,

        I’m sorry to hear about Azrael and I appreciate your response.

        The second round of tests came back leaning more towards carcinoma, but was still pretty wishy-washy. I have set up an appointment with the local Vet Oncologist here at the University. This is to hopefully get a more clearly defined diagnosis, treatment plan/cost, and prognosis.

        The hard part is know whether it is worth the stress and pain on Rio do go through all of the testing and treatments only to “give” her another 6-12 months. Those last months-year would be filled will Vet visits, pain, and stress on her. I think the appointment with the Oncologist will help clarify what is going on and what if anything can be done for Rio. I want to do my due diligence by exhausting all pragmatic possibilities.

        I would rather she receives no treatment and lives what is rest of her life as close to normal and stress/pain free rather than run her through the wringer for the last months of her life. Alternatively, if the Oncologist has some miracle plan, I am of course always open to the miracles.

        • Thank you Joel.

          Again, I wish both of you the very best.
          In any case, a lot depends on Rio’s overall well-being, especially if she
          eats well. Again, pain meds can help here and there are high-nutritional
          foods and food supplements for cats that might help too. At some point
          it helped to grind up his food well.

          There is a very comprehensive article on “TVP” called “A Review of Feline Oral Squamous Cell Carcinoma” that discusses available treatment options.

          Only in what turned out to be his last month one could really tell that my sweet little munchkin was horribly sick. That’s when his weight loss became alarming, his appetite was sketchy and he needed a lot more rest. Before that he was really pretty much the same. In his case, what made things worse is that in September the medication I used to treat his Exocrine Pancreatic Insufficiency (EPI) became completely unavailable (!) and the products I went through trying to substitute it just didn’t do. Then, when I had the tumor partially removed, the veterinarian I went to for that caused severe burns on one of his ears, because he used the electrosurgical unit with a metal heating plate (for body temperature stabilization while being under). If these two additional things hadn’t happened Azrael would’ve had it a lot easier.

  9. My beloved cat, ” Boots” or as I called her “Bean”, died 2 weeks ago. We had to euthanize. For me there is extreme guilt. I was a coward because I could not watch my wonderful, sweet, awesome, cat die. I worry that she missed me in the end. I feel intense sadness. I still look for her, always. She followed me everywhere. As a tiny kitten, she won me over when she would go to great lengths/ effort, just to lie on my chest to chill. When I took dishes out of the dishwasher to put away, she would meow at me like crazy. I don’t know if she hated, or was merely annoyed by it. She loved being under, and hiding, under any blanket, especially my goose down comforter. Those are the moments I miss when I think of my little best friend. I loved her, she was very special, friendly,(never hissed at anyone, except our mentally unstable neighbor, she called that on). I hope to see her again one day. Thanks for this place to vent.

    • Tom, I am so sorry for your loss!! I am getting ready to go then the struggle myself with my boy Macgyver. Never has something touched my heart as much as this darn cat!!! I understand, my boy is like my right appendage..he went for walks, car rides, ice cream everything. He saved me as much as I saved him!! Your Bean was lucky to have you. Think of the good times. I think no matter what we do guilt always plays a big part. We do the best we can and from what I read you did a lot!! She knew she was loved..hold on to that!! I just wanted to reach out..big hugs!!!

  10. My cat first started showing signs of a problem( not eating) on Jan18,2020. I took him to 2 different Veterinarian’s and 1 trip to the Emergency room ( not eating or drinking at this point)where they have specialists. 1 Vet diagnosed him with a respiratory infection, 1 with a sinus infection and the ER said IBS or Pancreatitis and to schedule an appointment with an Internist. Over $3000 later I recognized he was having trouble using his tongue. All of this info. was given to all the above doctors except trouble using his tongue and grooming. Do you know not 1 of those doctors checked his mouth at any of the prior visits!! If a cat is not eating wouldn’t it be one of the first things you would check? Anyway, my Macgyver was diagnosed with tongue cancer on Feb. 6. All his bloodwork came back remarkable. I was in shock I almost couldn’t drive home. I actually got lost finding my house. No biopsy was done, just a needle aspiration. I am unsure if I should proceed with seeing an oncologist as the -prognosis does not look good regardless. I feed him with a feeding syringe. I use high calorie food supplement, can cat food, powder weight gainer, and a powder liver and kidney support powder. I use a blender and add all this to can food with water and use a couple of 60 cc syringe to store it it in. I then fill up a bunch of 10 cc syringes to actually feed him. So far so good. At first he hated it, he never has eaten can food before so it was a transition. I give him water and kitten milk too all with syringes. It has become a full time job, but I’m not complaining. His poor tongue is now curling up and he is always drooling. He is my stinky boy. I clean him with fragrance free baby wipes and Johnson and Johnson baby bath towelettes. Not an easy task, as my Macgyver has always had a cat-itude! 😃 I have no children , he is my child. This has been so devastating and unexpected. His bloodwork exams everything was normal. He even had his teeth cleaned 6 months prior to all this. Makes me wonder if it was there and the doctor did not see it when he cleaned his teeth. I have lost all trust in veterinarians. I feel they know you are vulnerable and they hit you up with all kinds of costs and false hope to keep you paying. For this reason I’m apprehensive about seeing an oncol9gist. My current vet has given Macgyver Palladia, Panacur ( used off-label for cancer) Welactin, Vetri-DMD( immune support) and now prednisone. Thank you for letting me get this out!! I know this is a lot of info. My heart goes out to everyone. Reading your stories have given me the courage to share mine🐱 Thank you I appreciate any and all feedback that you may have.

  11. I feel very much for your situation. It is heartbreaking. I have been syringe feeding my Little Girl kitty for over a month now the same way with 10 cc syringes- yes it really is a full time job, but she is my baby, too.

    She has squamous cell carcinoma of the tongue itself and the oncologist prescribed Palladia and Onsior. Gabapentin has helped with the pain. She had a CT scan last week at a place that does radiation oncology. I have debated for weeks about it. They said about a 30-40 % have no response, about 30% do okay, and about 30% do well. However, the cancer will return regardless in a few months. It is thousands of dollars, but if I knew it would cure her I would try it. The fact that it comes back, and that her tongue is already so bad made me decide not to pursue treatment.

    Now she has gone downhill suddenly. She has painfully spasms when working the food and swallowing. She never liked can food either- only dry. I used to think if only I could get her to eat canned food she would be okay. But now her tongue can’t come out of her mouth far at all. Now the feedings feel like torture and I am afraid she will start to choke at some point.

    I have a home euthanasia scheduled for this Monday and am spending the weekend trying to keep her comfortable. It is heartbreaking when they really are so healthy other than their tongue. I just had her treated in January for hyperthyroidism with radio-iodine therapy and now her thyroid levels are perfect. She is 13 and I thought I bought her at least another 5 or so years with me, but then this happened. I feel for you.

    • Katie, OMG…I’m so sorry. I had to take a moment before trying to reply. I am replying now thru tears filled eyes. You are not alone, big hugs. There are no words that can convey my deepest sympathies. I feel only another pet person will ever get the way we feel about our animals. Some people look at me like I’m crazy for being-so distraught over my little man Macgyver. I sometimes feel I’m crazy!! You are such a good mom and know that you have done everything for your little girl. It is so hard to let them go when they have been such a huge part of your life. Just saved your little girl by giving her a home to start with, and the love to see her thru to the end😃 Please feel free…if you need to talk, vent, or anything I am a click away!!! Do not hesitate. I wish I had some better comforting words in this time but for once I am at a loss. I myself am going thru the same thing and it is devastating!!! Crazy how a little creature can run your life. We have given them an awesome life..remember that!!!! I hope your ok, just know your not alone!!! I am thinking of you during this dark, difficult time.

      • Thank you so much. It is a relief to share with others in the same boat. I’m sad that so many have to go through this. I let my Little Girl go on Sunday, a day earlier than planned. Sat evening her pain was not well controlled and she had bit her tongue I think. I had really wanted to enjoy another sunrise with her out on the porch, because she always seemed better in the mornings, but I couldn’t bear the thought of another bad evening. I found the Buprenorphine made her agitated, and unable to sleep, so I avoided giving it. The Gabapentin seemed to work best at letting her relax, curl up and purr in my lap. In the end I found giving the Buprenorphine dose a few hours after the Gabapentin might have been the best at making her comfortable, so that they overlapped. Pain is so difficult to gauge and they all react differently to the meds.

        A lot of my guilt is imagining that she suffered more than necessary. She would just sit hunched and salivating at times, like she couldn’t get comfortable. I was glad I found a home euthanasia vet who agreed to come out on a Sunday last minute. My Little Girl was always skiddish around everyone other than me, and I didn’t want her last moments to be fearful. This vet was amazingly compassionate and understanding, more so than any other I’ve been to. She specializes in end of life care.

        I never thought I was the type of person to need a lock of fur or a pawprint impression made, but I find these things very comforting now. I took as many photos and videos as I could of her crawling into my lap. Those are a comfort to me now. I have cried and cried over my precious baby, because all I ever cared about for so long was protecting her, and now she is gone. I was the only person she trusted to come to for comfort and pets. Her absence leaves a hole in my heart.

        Today I am less raw than yesterday, as much as I don’t want there to ever be a “new normal” after having her for 13 years. And even though I debated about trying radiation therapy, I do think now that it might only have prolonged her suffering. We can only do our best with what we know, and there are so many unknowns when it comes to cancer and medicine. It is so hard not to feel guilty and (for me) angry.

        I went to three different oncologists, so if you need any info about my experiences, let me know. I really feel for you and your Macgyver kitty. Thank you for your kind words.

  12. I have been googling everything I can about Squamous Cell Carcinoma especially in the mouth of cats and came upon this website. My 16 year old, (plus 4 months), Manx cat had a biopsy and was diagnosed with this cancer. There was a raw lesion on his upper gum and a protrusion under the left eye. Like most of you we had a couple of vet visits thinking it was something else before the lesion was found and then the biopsy was done. Now, the decision. I know what I have to do, but it is so hard to be make that final decision. I am feeding him baby food on a spoon with a few drops of water. I have not seem him drink for a couple of days and this is the only way I can get water in him. He still uses his litter box, hops up on his cat tree to look out the window and gets up on the couch beside me. But, overall he is lethargic most of the time. The left eye runs, and there are faint pink tinged places where he lays (drool) and of course that hard lump under his eye beside his nose. The vet said when they did the biopsy some of the bone flaked off, so it is eroding the bone in his mouth. This little fellow has been in my house for 16 years, slept in the bed with me and has been my comfort since the unexpected death of my husband 5 years ago. A cuddly cat who likes be carried over my shoulder as you would a baby when you are burping him. It is so hard, but reading about others going through this and making the decision to not let them suffer is a help. Thanks for listening.

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