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

Waiting and watching — but for how long?

Updated: September 26th, 2018

Have you been told to “just watch” a lump or mass on your dog by a veterinarian? I wouldn’t be surprised if you have. I too have advised that to my pet Guardians.  But how long is ok? What size is too big?  Are there actual guidelines?

In my veterinary training, I was taught that if a mass is not growing or changing in appearance, it is likely ok to do nothing and leave it – “just continue to monitor.” It’s been ten plus years since I started my medical oncology residency, and from my experience treating dogs and cats with cancer, that is not always the best advice.

While many skin masses are benign, some of these masses may also be slow-growing malignant tumors and it is better to remove them early, when it is more likely that the tumor can be completely removed with wide margins with the FIRST surgery.  I feel we are waiting too long, for too many masses.

This week I saw two cases that really depressed and frustrated me. Both were cats. I know this is a blog about dog cancer, but these cases illustrate exactly why it can be problematic to wait too long to take action – no matter what species we’re talking about.

Earlier in the week, I met Tiger, a big 16 year old cat with a recurrent tumor on his lower jaw, up front by the incisors.  It was first removed exactly a year ago. And now, it was back, and 3 cm wide. Think about how big a cat’s head is, and you’ll see that is a big tumor.

The tumor was a low grade fibrosarcoma, which, as in in dogs, is a malignant connective tissue cancer with tentacle-like projections that extend out from the visible tumor. It is these tentacles that make recurrence after surgery common if the surgery does not also remove a large amount of tissue around the tumor. We need a wide, clean “margin” of tissue. How big a margin? That’s what can be tricky to figure out by “just monitoring” it.

This week, as I visually inspected Tiger’s mouth with our surgeon at our practice, I was cautiously optimistic that surgery was an option. But just looking at a tumor doesnt tell the whole story, so, to be sure, we did a CT scan. Unfortunately, based on the CT scan, the tumor and its tentacles extended too far back. Surgery was no longer an option, as there was no way to get wide enough margins, and (most importantly) leave a functional mouth so the kitty could eat once he recovered. The surgery last year did not get wide enough margins. We didn’t want to do another resection (surgery), because we would end up with a minimal margin, and that would lead to another recurrence.

The second kitty I saw this week was Tulip. She also had a low grade sarcoma, a peripheral nerve sheath tumor, on the right side of muzzle. Tulip’s Guardian first visited her vet five months ago, after she noticed a small mass on the side of her face. Her vet prescribed steroids and antibiotics, which did not help for long. A month later, the mass was biopsied. At that point, the mass was still small, about 1cm, and likely still a good candidate for surgical removal.  Unfortunately, I did not see the case until this week, four months after that biopsy. At this point, the mass is greater than 3 cm.

The point I’m making here is that for both of these cases, the cancers might have (essentially) been cured if they had been treated with more assertive methods early, while they were still small tumors. Tiger’s first surgery should have had much wider margins, to reduce the risk of recurrence. Tulip should have had a big surgery with wide margins on that small, 1 cm tumor, rather than taking a wait-and-see approach.

Big surgeries, early, on small tumors, can be really helpful for these sarcomas. As in dogs, the metastasis rate is low for sarcomas, and chemotherapy is typically not recommended once the surgery removes the tumor.

Instead, I had to deliver the frustrating news that we are now beyond surgery as an option, in both cases. We now have palliative radiation, palliative pain medications, and anti-inflammatories. Palliative techniques are not designed to remove the cancer, remember. They are meant to help the dog, or in this case, cat, feel better while the cancer continues to do what cancer does.

Understandably, both guardians wept when I explained the situation. My heart was heavy, as I outlined the lack of good therapeutic options to rid these cats of their once-treatable cancers.

Dr. Dressler and I write in our book that there’s always something you can do to help your dog with cancer – and there is. You can always improve quality of life, change the diet, start supplements, and, of course, take advantage of palliative and therapeutic treatments.

But please – if you’ve landed on this page because your dog (or cat, in honor of Tulip and Tiger) has a lump or a bump, and you have been told to wait and watch it … rethink that.

In my next post, I’ll give you some guidelines for how to handle a “wait and see” situation.


Dr. Sue

Leave a Comment

  1. julia on March 11, 2013 at 4:31 am

    Dear Dr. Sue, my wonderful Dog Cancer Survival Guide along with Dr’s D’s acopops have just arrived in London courtesy of Amazon, and I am finding the book very helpful in coping with Nutty, my 15 year old Sheltie’s recent diagnosis of squamous cell carcinoma in his mouth. Unfortunately we discovered this growth quite late and my vets do not recommend surgery as it would mean removing too much of his jaw. He is in amazingly good form, enjoying his walks, does not appear to be in any pain and has a good appetite. he is just the same as always. However the tumour is 1 and a half inches, is now growing out from his lip, and is now visible when his mouth is closed. Although I understand that it is difficult to give advice over the internet but I wonder if you know of any good oncologists in the UK who might be able to help? He is taking apocaps, shitake mushroom extract, colloidal silver and a homeopathic supplement and I have changed his diet. I must be realistic but I want to do all I can. Best wishes, Julia Stephenson

  2. Tipsy's carer on January 7, 2013 at 1:19 am

    Hi, I’ve got a big decision to make, and would appreciate any guidance. Tipsy came to live with me 3 years ago, as her original owner moved to rented accommodation, and couldn’t have pets. Tipsy is a Saluki/Border Collie cross now 11yrs old. Lovely temperament. April 2012, as we were on an evening walk, Tipsy collapsed, her back left leg gave way. She couldn’t get up. I ran home, got my car, a lady helped me get her in. Off to the Vets, were she had always been for treatment since a puppy, so they knew her history. Tipsy couldn’t stand, and was crashing about the surgery in an attempt to get her movement back. Vets initial reaction was to put her down, which I was horrified by. Vet knows I have no insurance on Tipsy, and at the time a limited budget. We agreed to give her 12 hours, she was given Diazepam to calm her, I could feel her sink into my arms and relax as the injection worked. She had a drip in her leg, too. Tipsy stayed in overnight, I got a call to say she was recovering. I went and collected her the next afternoon. She also had Epiphen tablets. Tipsy slept on and off for nearly 2 days, When she got up on the second day to have a drink, I noticed a small lump on her leg, next to the site were the drip had been. Rang the vets for advice, said I should bring Tipsy in. Lump was aspirated, results came back, a spindle cell tumour. At the time, the lump was the size of a walnut. The vet denied it could have been caused by the drip, even tho it was right next to the drip site. They didn’t suggest removal, and implied cost if I did want lump removed would be prohibitive, possibly a £1000. As the lump got bigger,(now size of a pingpong ball) I went and got a 2nd opinion. Vet said it could be removed, but as clear boundaries were needed, lump now probably too big, and could be risky. Was advised lump would eventually split, as the skin would reach a point where it would stretch no more. Tipsy is fine, eats well, can still run to chase squirrels, but the lump has got to the size of a tennis ball. It looks awful. Why the first vet didn’t remove it when it was tiny I will never know!!!!!! A friend has just told me to try a vet she uses. Went on Thursday, he is willing to try and remove lump, but told me it’s 90% likely to return, but could give her an extended time. He removed one last week that came away like shelling peas. Also did one on a dog that had come over to U.K from Greece, and lump wouldn’t come away, dog had to be euthanaised.. Bearing in mind Tipsy is 11+ years old, what should I do???? I feel helpless watching this lump grow, but feel I may condemn her to death if Vet operates and lump accelerates. Please can anyone help me make a decision? Thank you, in hope.

  3. Kasey McMahon on January 2, 2013 at 4:10 pm

    Dear Dr Ettinger,
    I am simply devastated, my 10yr old French Bulldog was recently diagnosed with MCT at the base of his back leg. This began as a cyst removal in October that was about the size of a golf ball. The vet that did the sx did not send it for testing because he did not think that it showed characteristics of being cancer. Once his post sx meds were done, I noticed fluid build up and lumps that I thought were lymph nodes at the time appear. Second vet visit, vet said “I’ve never seen anything like this before, but it doesn’t look like cancer, so more antibiotics and pred. Again he responded well but as soon as he was done with the meds, the same reaction. The third visit just like the last visit, but this vet did several needle aspirations and did not see any cancerous cells, so what a relief we thought. More meds, same as before. My final visit to the vet, I saw a different vet who quickly said this is serious and we need to remove these cysts right away. I was crushed, and decided to cantact a friend of mine who also happens to be a vet, but his practice is too far to be my regular vet and he confirmed that it was a MCT right away and was very concerned. Now my question (sorry for rambling, perhaps this is just therapeutic on my part), my friend mentioned creating a vaccine for MCT using a tissue sample from his tumors. I have never heard of this before and I wondered what your experience was with this approach? The cost is outrageous naturally, I was told that it would be somewhere between $2000-$3000. Due to the cost I am leaning more towards chemo, but I’m just so confused about what direction to go. I realize that you are limited on what advice you can give, but anything would be helpful. I am trying to deal as best I can, but everything I have read about MCT is grim, I haven’t found any success stories and I feel like I only have a few months left. Any information or insight would be helpful.

  4. Cheryl on December 31, 2012 at 12:01 pm

    So glad I found this website.

    My 8 year old Shadow has a peripheral nerve sheath tumor in the lumbar region – it was growing into his spinal cord. His symptoms were a limp that developed in July – vet thought it was a CCL injury but when they took in in for surgery the othro said it was not a CCL injury. Nothing was showing up on the xrays. He seemed to recover after that and then in September started limping again and having paid. Had an MRI done and the diagnosis was made. I was told surgery was not an option but I could try radiation. He had 19 radiation treatments and has improved greatly. The onocologist and neurologist and very pleased and I think a little surprised. Does radiation work for these kinds of tumors? They won’t tell me how long he has. It has been 4 months now since his diagnosis and he was given 2 weeks to a month without any treatment.

    I feel so helpless about my Shadow but he seems happy and is doing well for now. Do you have any experience with these kind of tumors? He was never biopsied so don’t know if this is a low or high grade tumor. He had been having subtle symptoms in his walk from last March on.

    Thanks for your time.

    • Dr. Demian Dressler on January 2, 2013 at 12:22 pm

      Dear Cheryl,
      well, if its working…there you go. Yes, nerve sheath tumors are one of the various ones that radiation can help with. The reason why the oncologist won’t give you survival data is probably because it is not known for your specific case.
      I would definitely start with this post:
      and I most definitely would read the Dog Cancer Survival Guide ( There are many steps that can be done that may contribute to your Shadow’s longevity and also life quality.
      Dr D

    • Dr. Susan Ettinger on January 13, 2013 at 12:51 pm

      Hi Cheryl,
      Sorry to hear about Shadow. Nerve sheath tumors are a type of soft tissue sarcoma, but the ones involving the central nervous system/spinal cord are different than the ones involving the skin and/or subcutaneous tissues. I really cannot give a prognosis without being more involved directly in the case. It sounds like you have a good team on specialists. I hope Shadow continues to improve and do well.
      All my best, Dr Sue

  5. Ruth Dixon on December 8, 2012 at 12:03 pm

    I have been reading the canine cancer blog for quite some time. I have a close to home interest in that I lost one great girl to bone cancer and my other girl has a four + year history of mast cell tumours. The first MCT caught me by surprise. It looked like a wart that had scabbed over. At the time this one was found and operated on, there were two other ones. All removed. She has lost most of her tail because of another one (looked like nothing) and she has just had two more removed. All in all she has about eight (I’ve lost track). I am now always waiting for the next. My personal advice . . . . there is really no “watch and wait” period that works. A fine needle biopsy is the only thing that will give you some peace of mind. Well not if it is “something”, but at least you will never kick yourself because you watched and waited too long. My old girl will be 13 (pretty good for a large dog) and she is still here because I have everything suspicious, biopsied. Yes it gets expensive but no one ever said that caring for your four legged children could be cheap. Something to think about when you let them into your heart.

    • Dr. Susan Ettinger on December 29, 2012 at 6:09 pm

      Great advice, Ruth! Thanks for sharing. Wishing your dog continued health!
      All my best, Dr Sue

  6. Dog Owner on November 27, 2012 at 4:54 pm

    I am fortunate that my vet aspirates every lump I find. Most have just been fatty tumors. But, one on my dog’s leg had doubled in size literally overnight (between the time I called the vet and the vet’s appointment the next morning) & test showed “funny” cells. At the time, my dog was almost 13 & surgery was scheduled immediately. Fortunately, turned out not to be cancer & he fully recovered. But then, this past summer, I felt 2 lumps under his throat – he was diagnosed with advanced lymphoma. Due to his age (now almost 14), we decided not to do chemo, instead kept him comfortable. He lasted 3 months.

    • Dr. Susan Ettinger on December 29, 2012 at 5:48 pm

      Thanks for sharing, and I am sorry about your dog’s lymphoma.
      With sympathy, Dr Sue

  7. Gillian on November 26, 2012 at 11:22 pm

    Can you please help me , my dog just got spayed four days ago because of ovary infection . I brought her to the vet because i found bumps near the nipples at the rear end and they gave her an x-ray. The vet said it was early stage of ovary infection and hence they spayed her . However the point is even after operation the bumps were still there. (At first there was only one). The bumps are under the skin , the biggest is 1cm in diameter. Some are visible while some can only be found when touching the area . Does she have Mammary cancer ?

  8. Chrissy on November 26, 2012 at 9:48 am

    I noticed a very small growth on the outside of my dog’s bottom lip at the beginning of November. It was whitish-pink and hard/rough. It seemed to grow so I had my vet look at it about 10 days later (11/14). She just looked at it and said it was nothing – probably a wart or cyst, and that it would go away in 6 weeks.

    By the time I went home for Thanksgiving on 11/17, it seemed to be growing even more. I went to my family’s vet on 11/19 and had it aspirated. The vet used two needles and took two samples. She wrote down that it was 2 mm at this time. The cytology report said there was “low cellularity” and noted the presence of anucleated squamous epithelial cells, mildly increased neutrophils, rare macrophages, and rare pleomorphic bacteria. The comment states, “the presence of squamous debris with the concurrent mixed inflammation could suggest that this is a ruptured keratin-filled lesion which has incited a significant inflammatory response with a secondary bacterial infection.”

    However, it also states that because cellularity is low, the sample maybe not be fully representative, and that the squamous debris could be a result of superficial contamination. The recommendation is “correlation of these findings with the clinical impression of the patient.”

    The vet’s advice was to “watch & wait.” She suspects it is a cyst that has “filled in” and that it is not malignant. She said generally mast cell tumors (her original concern) exfoliate very well on aspiration. She also felt she got good samples on her aspiration.

    Watching and waiting is making me nervous. At the beginning of November the lump was <1mm and now it is probably 4mm. It is still really small, so I feel like the vets think I'm being silly (and I can't keep paying for office visits just to get "advice"). My dog has had two surgeries in the past year (she was spayed at the shelter and then had to have a surgery to repair an abscess that resulted from that spay), and I would much prefer not to have another surgery because of how dangerous it is (the cost is less important to me). However, above and beyond that, I want my dog to be okay.

    The vet who did the cytology said that cysts do grow and that cancer typically would not increase in size this quickly (it's more of an inflammatory response?). However, the lesion is rough on the outside and is growing out of the skin (it is not below the skin). It does not look like a cyst to me.

    I don't know what to do. Like I said, I don't want to keep going to vets and spending money on office visits, but I want to take care of my dog. She is a 3-4 year old lab mix. I have only had her for a year and that is way too soon for me to lose her 🙁

    • Dr. Susan Ettinger on December 29, 2012 at 5:43 pm

      I agree with your vet that MCT typically exfoliate well, but any time the cellularity is low, one cannot be certain of the diagnosis. How is the mass now? Another option is a punch biopsy which can typically be done for small masses less than 1 cm. Sometimes our surgeon does them with a local block and sedation instead of anesthesia, which keep costs down. I cannot give you specific medical advice over the internet and this may not be a good option in this case near the lip, but I hear your concern, and it may be better to get a procedure to remove it, and if it’s benign, you’ll have that peace of mind.
      Good luck, Dr Sue

  9. Gillian on November 26, 2012 at 3:00 am

    Dr Susan,
    I bought my dog to have an x-ray as she had small little bumps near her breast .The vet said that the x-ray showed no tumor but the vet found out that she had infected ovaries. And hence my dog got spayed 2 days ago .The point is , after surgery there are still small bumps near her rear end (near her nipples). Does she have Mammary cancer ? The bumps cannot be seen , it only can be felt by touching the area ( the bumps are under the skin).At first there was only one bump but then few weeks later a few more popped up.The bumps did’nt grow in size .
    Size :about 1cm diameter

    Note : She’s 11 this year

    • Dr. Susan Ettinger on December 29, 2012 at 5:35 pm

      I recommend the masses get aspirated to determine if they are cancer or not. Also, 50% of mammary masses are benign, and of the 50% that are malignant, half of those are cured with surgery. So 75% of mammary masses are cured with surgery. You cannot tell by touch or size. Good luck,
      All my best, Dr Sue

  10. Elliott Garber on November 21, 2012 at 9:40 pm

    As a general practice vet seeing little lumps and bumps and often advising to “wait and see”, this article definitely interests me! I often give clients the option of having something removed at the beginning, even if it does appear to be completely benign. However, I usually tell them truthfully that if it were my pet I would probably wait until there were more signs to worry before going through the risks of anesthesia and surgery. Thanks for the insight.

    • Dr. Susan Ettinger on November 24, 2012 at 6:07 pm

      Dr Garber,
      Thanks for reading and sharing. I too was taught the wait and see approach, but I have had to rethink this approach as I see and hear about too many pets that this approach is failing them and their tumors. Too many pets have masses that were once surgical and now there are no good options. I appreciate all the work the vets on the “frontline” do. Vets like you i general practice are the first ones to see these masses, and I am just trying to have us re-evaluate this approach. I am hopeful together we can help more dogs and cats catch those tumors earlier. Aspirate and biopsy! =)
      Thanks again for contributing!
      All my best, Dr Sue

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