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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Does my dog have cancer? What NOT to rely on!

Updated: December 11th, 2018


Glad to see so many readers these days! Thanks everyone.

I have noticed that there are some misconceptions about dog cancer floating around that perhaps could be clarified a little bit. Specifically, there are things that people are looking at to deduce that their dog’s lump is NOT cancer…but the problem is that some of the reasons (to support a theory that their dog’s growth is “fine”) are not valid.

Here are some classics in the area of:

What Not To Rely On With Certainty

1. Your dog’s behavior.  Dogs can have pretty serious health problems and still walk around, eat, be in no apparent pain, etc.  Malignant tumors may not show any overall body signs whatsoever.  Anyone heard the phrase….”the doctor found a lump in my breast?”  Let’s think about this for a minute.  The doctor found a lump.  The woman was totally unaware there was a lump!!  This tells us that you can have a life- threatening cancer going on that is utterly without any overall signs.

2. How the lump feels and looks on a physical examination at the vet’s.  Okay, all of us vets have been guilty of feeling a mass and proclaiming the diagnosis (Fatty Tumor! Cyst! Adenoma! or whatever).  Folks, the reality is this: a very high percentage of masses with that feel and appearance actually are what they feel like and look like.  But, not all of them!  If I see 20 dogs with a soft mass under the skin that feels like a fatty tumor, I would not be surprised if one or two were not. I have encountered growths that for all the world feel like fatty tumors (lipomas) and turned out to be mast cell tumors or hemangiopericytomas (nerve sheath tumors), or even sometimes hematomas (blood pockets from some kind of impact or trauma).

Both of these (exam findings and your dog’s behavior) are unreliable.  Yes, sometimes we can get a high probability of a diagnosis and everyone is comfortable playing the odds.  But consider this:  how many of us wear our seat belts and how many of us wreck our cars?

Take home message: make sure you are aware that if you opt against a fine needle aspirate (see the last blog) or a biopsy (see the entry about Bjorn), you are playing an odds game that is not 100% versus 0%.  Some of the dogs with masses that look like they are benign growths and will fool everyone.  They come back to bite us later.

Best to everyone,

Dr Dressler


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  1. paintr49 on December 18, 2014 at 11:05 pm

    I have an 11 year old welsh corgi. She has been having allergy problems, first chewing her feet red, then her ears have begun to itch as well as her snout. It’s all red and she’s loosing her fur the cortisone shots don’t work anymore and my doc wasn’t to do a biopsy. I’m wondering why? also I’m afraid of the cost. I’ve spent about $500.00 on her in vet bills just in the last month. Any suggestions to make the allergy better? I can’t afford to keep going to the vet. Thank you

  2. Susan Kazara Harper on December 11, 2014 at 9:26 pm

    Mar, Can you contact the Sam Simon Foundation and let them know you’re worried about waiting based on her symptoms? They may be able to advise, or move things up. Don’t worry about what you did or didn’t do in the past. Take care of today and your girl. If she seems in real discomfort and you can’t contact the foundation, then yes, get her to a vet to try to help manager her symptoms please. When you take a breath and step back inside yourself, you’ll be able to make clear decisions. Good luck to you both!

  3. Nelson on December 10, 2014 at 8:07 pm

    Our 10 yer old German Shorthair female has two lumps we found today. One is in her armpit and the other is on a breast nearby. She also has some weird-feeling tissue in her jowls. We don’t have much $ to spend at a vets office. Do you think she’s got cancer of some type? The lumps have appeared very recently.

  4. Shorkie on December 3, 2014 at 5:29 pm

    I Have A 1 year old female shorkie.. & she has a few lumps growing on her stomach/chest…are these her breasts or something else?

    • Susan Kazara Harper on December 3, 2014 at 10:33 pm

      Hi Shorkie,
      You will only know for sure by going to your vet. We cannot really make any comment or determination online. If they are regularly spaced and consistent top to bottom and side to side, with an even number, they could be her breasts/teats/ etc. (Several terms used). But you need more information to know whether what you see is normal for a one year old dog. Good luck!

  5. Susan Kazara Harper on November 25, 2014 at 12:21 pm

    Hi Naomi, become your own expert. Tell the vets what you want and expect from them. You hire them and pay for their services. The love and empathy come from you, and you can use the vet’s diagnostic expertise, along with your own knowledge as you become an expert in this journey, to make the best decision for your girl. Please don’t give up.

  6. Patty on November 17, 2014 at 8:23 pm

    My sisters dog has a mass near his anus. Vet did not explain, just that he was “sick” and she can’t breed him. Is this possible ?

    • Susan Kazara Harper on November 18, 2014 at 7:46 pm

      That’s not goof enough Patty. Any vet worth his or her degree would do a test and get a biopsy to determine whether the mass is malignant, and then explain what can be done. Absolutely it is advisable not to breed from any dog with a lump because if it is cancer it can possibly give the pups a higher possibility of developing cancer. But more information is needed for the health of the male dog. Good luck!

  7. Susan Kazara Harper on November 5, 2014 at 7:31 pm

    Hi Virginia,
    You sound worried about the glands, and I would be too. Have you directly asked your vet to test the lumps for cancer? Sometimes it’s difficult to be direct when we’re dealing with an expert in their field. But you want to know. You might want to write down questions in advance of your next visit, or get the practice on the phone and ask these questions…
    ? Is it possible that the lymph nodes are cancerous?
    ? Can we test them for cancer?
    If you don’t feel you’re being heard, be prepared to either ask to be referred to a specialist, or just find another vet yourself. It’s completely within your rights, and I suspect that this will gnaw at you until you really know what’s going on. You know something is not right with your boy, and you’re the one who can take action to help. Deep breaths. Find your answers.

    • doglover on December 29, 2014 at 3:46 am

      Our Golden had the same lumps…it was Lymphoma. Good luck with your furbaby. We’ll pray it’s treatable.

  8. Virginia on November 5, 2014 at 10:42 am

    HELP!!! I have a 9 year old Maltese who has had swollen lymph nodes in his neck with no other symptoms for about 4 months now. I took him in right away and the vet put him on an antibiotic for 3 weeks. Took him back for a re-check and they were still swollen. The vet gave him another week on the antibiotics. Went back, still swollen, then the vet did a blood test and found low thyroid levels and nothing else. The vet gave him some medication for the thyroid and said to bring him back in 6 weeks for another blood test. The lymph nodes are still swollen, not huge, but still there and the vet doesn’t seem concerned? I did notice while on the antibiotics, the swelling would fluctuate daily and the vet had never seen that before, but still not concerned. Now that he has been off the antibiotics, the lymph nodes stay the same size. About the size of a good size gumball.

  9. Naomi on November 2, 2014 at 2:37 pm

    Hey guys. I really need help because my 9 year old terrier mix (not completely known) had a lump in her breast about a year ago. She was fine and completely active, so we let it be because financially we couldn’t get her much help. A few months ago (about March or April), she had to have surgery because of the lump making her feel extraordinary pain. The doctor said it was probably due to the pressure caused by the liquid the lump was producing as the teat would have some clear liquid being released. She had to have the whole gland removed just in case and the doctor told me to continie palpating after she heals to check for more lumps. She was fine until two days ago when I felt several small circular lumps all over her lower pairs of mammary glands. She’s not feeling pain, but I’m worried about it. The last surgery was so traumatic on her that I don’t think she could last another. As well as her being so old. Please contact me if you can to try and help me figure out what is going on. My email is she was never spayed, and has never had puppies, which seriously increases her rates of cancer. Please help.

    • Susan Kazara Harper on November 2, 2014 at 9:20 pm

      Dear Naomi, I know how scary this is. But you’ve got to take some deep breaths. It’s really best to get her to the vet and ask him or her to check these new lumps. It may not be the same thing. While the idea of more surgery or treatment is worrying, until you know what you’re dealing with there is no point wasting all the energy on fear. In addition to this, you need to get her nutrition absolutely the best you can. I don’t mean by spending a lot, but by feeding her real food. The Dog Cancer Diet has wonderful suggestions for foods which are not only beter for her, but can actually help her body fight back. The diet is in the Dog Cancer Survival Guide book, and you can also go to and download the majority of information. Food is the foundation of health, so you can get busy with this. If a procedure is recommended for her, remember that last year the lump was very big and painful. It sounds different now, and she may handle things differently. But it’s your job to keep her calm and happy. She’ll only be that way if you are. It’s hard, but we owe it to our pups. Please make thay appointment, and we’re all wishing you both the best.

      • Naomi on November 3, 2014 at 3:11 am

        One of the biggest issues i have at the moment is that i’m living in Kenya. The vets here are even worse than those in the US when it comes to dismissing cancer patients as write-offs and not even bothering to check a lump for malignancy. After the last surgery, the lump was thrown out instead of being tested. I feel as though I will end up taking her to the vet, end up being told that there are too many lumps, and that since she is going to end up being in pain soon, that they should just put her down. The doctors here aren’t trained in empathy for pets.

  10. Tazsara on August 17, 2014 at 1:57 pm

    My dog has lumps and bumps all over his body.He had a lump on his chest that I was concerned about.I took him to the vet she said dogs get bumps when they are old.This lump was getting bigger and bigger I kept taking him back and she said it was nothing to worry about.It finally burst well now she was concerned.She didn’t test it or tell me what it was but I have to put him down.

    • Susan Kazara Harper on August 17, 2014 at 2:20 pm

      Woa…… Tazsara, my goodness this is so hard. Is your dog still with you or have you let him go?

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