Saturday, October 1, 2011

Mast Cell Tumors In Dogs & Cats Continued....

Yesterday we talked about the basics of Mast Cell Tumors in dogs and cats - this post focuses on Grading, Staging, Prognosis and Treatment Options. 

Grading and Staging and location of the tumors is crucial in determining how to treat the patient.  Also, controlling any symptoms your pet has will help, such as lack of appetite, nausea, itching, decreased energy, etc.

Grading the Mast Cell Tumor

This is the best type of mast cell tumor to have. While it may tend to be larger and more locally invasive than can be seen with the eye, it tends not to spread beyond its place in the skin. Surgery should be curative. About half of all mast cell tumors are grade 1 tumors and can be cured with surgery alone.  If the tumor cells are close to the edges of the surgery site, the tumor can grow back, so prompt removal and wide margins away from the tumor is essential.

The behavior of this type of tumor is somewhat unpredictable. Recent studies have shown that radiation therapy administered to the site of the tumor can cure greater than 80% of patients as long as the tumor has not already shown distant spread.  You may also elect chemotherapy.

This is the worst type of mast cell tumor to have. Grade III tumors account for approximately 25% of all mast cell tumors and they behave very invasively and aggressively. If only surgical excision is attempted without supplementary chemotherapy, a mean survival time of 4-5 months can be expected.

Staging the Mast Cell Tumor
In order for a rational therapeutic plan to be devised, the extent of tumor spread (or stage of the tumor) must be determined.  The tumor is staged 0 through IV as described below:
  • Stage 0: one tumor but incompletely excised from the skin.
  • Stage I: one tumor confined to the skin with no regional lymph node involvement.
  • Stage II: one tumor confined to the skin but with regional lymph node involvement present.
  • Stage III: many tumors or large deeply infiltrating tumors, with or without lymph node involvement.
  • Stage IV: any tumor with distant spread evident. This stage is further divided into sub stage A (no clinical signs of illness) and sub stage B (with clinical signs of illness). In order to determine the tumor stage some probing of other lymphoid organs must be performed.
Your veterinarian may recommend the following tests regardless of what kind of cancer your pet has, although specific comments regarding mast cells are included:

Basic Blood Work
A basic blood panel is part of this evaluation process and should be obtained at this point if it has not already been obtained. This testing will help show any factors that limit kidney or liver function and thus determine what drugs of chemotherapy can or cannot be used. It also will show if there are circulating mast cells in the blood (a very bad sign) or if there is anemia (low red blood cell count) that might be related to the tumor.

Buffy Coat Smear/Bone Marrow Tap
The buffy coat is the small layer of white blood cells that floats atop the layer of red blood cells when a capillary tube of the patient's blood has been centrifuged. This layer of cells can be smeared onto a microscope slide and checked for circulating mast cells. This process was once considered an important method of evaluating mast cell spread in dogs but has more recently been found not to be very helpful. This test is still of use for cats but has been largely supplanted by an actual bone marrow tap for dogs. The idea behind both of these tests is to determine if there are malignant mast cells in the bone marrow (malignant cells circulating in the blood/found in the buffy coat would indicate malignant cells in the marrow).

Local Lymph Node Aspiration
The lymph nodes local to the site of the tumor should be aspirated (if they can be found) to see if the tumor has spread there.

Aspiration of the Spleen/Radiographs and Ultrasound
The size of the spleen can be evaluated with radiographs but ultrasound guidance is generally needed to withdraw some cells for testing. The spleen is an organ of the lymph system, and thus the pet should be assessed for tumors in the deeper lymph organs such as the spleen and abdominal lymph nodes. While the mast cell tumor does not spread to lungs the way other tumors do, there are many lymph nodes in the chest and it is helpful to radiograph the chest to assess the size of these lymph nodes and thus help determine the extent of tumor spread.

Other Factors in Prognosis
As if grade and stage aren’t enough to evaluate, other factors add in to the prognosis.

Anatomic Location
Mast cell tumors arising in the following areas tend to be the most malignant: nail bed, genital areas, muzzle, and oral cavity. Mast cell tumors that originate in deeper tissues such as the liver or spleen carry a particularly grave prognosis.

Growth Rate of Tumor
Tumors that have been present for months or years tend to be more benign.

Special staining of tumor samples: The pathologist can use a special silver stain on the tumor sample. The uptake of this stain correlates to the rapidity with which the tumor cells proliferate. There are also numerous specific stains for tumor proteins. The idea is that further information about the behavior of a grade II tumor could be obtained by staining for these factors. This is still being evaluated for many types of cancer.

Therapy for mast cell tumors consists of surgery, radiation therapy, and chemotherapy (as is the case for almost all types of cancer). What combination of the above is chosen depends on the extent of spread and malignant characteristics of the tumor.

If the tumor can be cured with one or even two surgeries, this is ideal. Mast cell tumors are highly invasive and very deep and extensive margins (at least 3 cm in all directions) are needed. This can be a problem for tumors located on the neck or in the mouth, or far down on a limb where there isn’t much pliable tissue to work with. Further, the inflammation associated with manipulation of the tumor can lead to extra swelling, bleeding, and even a drop in blood pressure. In one study a 10% incidence of wound healing failure (dehiscence) was observed with mast cell tumors. The biopsy sample obtained will not only yield the grade of the tumor but will include a measurement of the tissue margin (the width of normal tissue that has been excised around the tumor). The width of the margins will go far in determining if further treatment is needed. If the margins are narrow or margins indicate there is still tumor left behind then a second surgery or even a course of radiation therapy may be desirable. Clean margins are generally defined as a 1 centimeter margin around the tumor in all directions. If the margin is clean, theoretically the tumor should be completely removed but it is still a good idea to keep an eye on the area over the years.

Radiation Therapy
While radiation therapy tends to be expensive and requires a specific facility that may or may not be conveniently located, the potential to permanently cure a grade I or II mast cell tumor is likely worth it. Radiation is a therapy most appropriate for localized disease. If the tumor stages so as to show more distant spread, radiation becomes less helpful and medications (chemotherapy), which can be delivered to the tumor through the patient's bloodstream, becomes needed.

Currently three anti-cancer drugs have been particularly helpful in combating mast cell disease: prednisone, lomustine, and vinblastine.  Prednisone is a corticosteroid, and corticosteroids seem to be directly toxic to many forms of cancer, including mast cells and can lead to a brief remission even when used alone. Corticosteroids are inexpensive treatments and definitely worth trying should more powerful chemotherapy drugs be considered too expensive or if your pet cannot tolerate other forms of treatment.  Ongoing research will continue to find more drugs to be added to the arsenal of therapy for different types of cancer.  There is also research being done on vaccines for cancer, viruses that attack cancer cells, and nanotechnology to treat cancer.

Another issue with mast cell:  the mast cell tumor releases histamine-containing granules that lead to inflammation and increased stomach acid secretion.  These unpleasant symptoms may be alleviated with the use of H1 blockers (antihistamines such as diphenhydramine and others) as well as H2 blockers (such as famotidine and others).  These medications help palliate the inflammatory effects of the spreading malignant mast cell tumor.

After diagnosis of mast cell tumor has been made, consider consultation with an oncologist for the most up to date information on chemotherapy or other adjunctive treatment.  Even for those pets who cannot be cured, most pets who are treated for cancer are still able to enjoy an improved, robust life. In most situations, animals undergoing cancer treatment experience limited to no decrease in their quality of life.

By: Dr. Dana Lewis


  1. Hi Dr. Dana,

    I was happy to seen an article on Mast Cell Cancer. It's a long story, but I recently lost my 9 yr old terrier mix to what was supposed to be mast cell cancer. I noticed a slightly red spot about her bottom mammary gland (smaller than a mosquito bite) and took her in to be checked in Nov. A temp vet checked and tried to aspirate the area and could get nothing. Over approx 3 months a large lump appeared....don't think it was aspirated at the time, but my vet removed what he thought was a mammary tumor and she healed exceptionally quick. I asked my vet if he checked it after the surgery to see if it was benign or malignant.....he said he had preserved it would get to it(never did). When I had the sutures removed a week later, he confirmed that it was benign since she healed so quickly...he said if it was cancer it wouldn't have healed quickly. So within 3 mos. the tumor returned, plus other lumps which I asked him to aspirate....he said they were all fatty tumors. Below the mammary tumor area, her leg had swollen as well. He did surgery and removed the tumor and found others below and on the other side. He called me from the OR and asked me if I wanted him to close her up and bring her home or put her to sleep. I asked if the tumors were malignant.....he checked, called me back and told me she had mast cell cancer. The whole process was a total shock, since according to him earlier....all the tumors were fatty tumors and benign. I had no choice but to put her down....I didn't want her to suffer with recovering only to have to put her down shortly anyway. Does her condition sound like Mast Cell Cancer? Other than the lumps, she had no other health issues or lesions on her skin. Maybe Mast Cell Cancer is a general term for various forms of cancer? Needless to say, I would definitely not return to that vet! Seems like I would have seen more symptoms prior to having to put her down if she had Mast Cell Cancer? I'd appreciate your opinion, after the fact.....Thanks....Claudia

  2. Hi Claudia,

    I am so very sorry to hear about your terrier. My personal concern is that the original mass that was removed was not sent for pathology. That is really the ONLY way to grade/stage it properly so you know what the best course of treatment is. Just because something heals quickly does not make it benign. Sure, if a surgery area is not of healthy tissue, it makes it hard to heal - however - the mass should have been removed with wide margins (into healthy tissue) so healing should have gone well regardless of malignancy. I have had a spay surgery site not heal well - wound healing has many factors. You were a good mom and kept it clean and made sure she did not 'mess with it'. :)

    If he checked one of the tumors during the second surgery and saw mast cells - than she probably had mast cell cancer and most likely the first tumor was an aggressive form and was spreading.

    Mast Cell Cancer is definitely a specific type of cancer and a dog can act/look totally healthy except for the lumps - however if left untreated, they can become sick - but that can take time. So it is not unlikely that she did have it - but was in a generally healthy state. For example, many humans have a type of cancer and just 'happen to find a lump' - but they feel great. So it is possible.

    I think the only thing I personally would have done differently was made sure the first mass was sent to pathology - that way I would have been able to give you a definitely diagnosis, treatment plan and set expectations.

    I had this one patient that I will never forget. She had a mass on her 'scruff' area (she was a dog though - so imagine a dog scruff) and the owners insisted it was a thorn or something stuck in there. When I aspirated it - all I got was 'infection' cells. No mast cells. So we treated with anti-biotics and the mass went away. About 2 months later - it reappeared. Again - it was nasty and all I could see where white blood cells. Long story short - they reluctantly let me take her to surgery to remove the mass so we can send it to pathology to see what it really was. It was VERY large and had 'fingers' that crept deep into her shoulder muscle. I got the results and it was an aggressive type of Mast Cell Cancer. Unfortunately due to the size of the 'fingers' that were traveling deep - I could not get all of the tumor out. She was started immediately on chemotherapy and did well for MONTHS! The owners had a wonderful 10 months with her and she finally began getting sick, swelling up, etc. So we said goodbye. A mast cell tumor can 'hide' - in this case it was causing the skin above it to be infected and my little needle could only see the infection - it required me removing the tumor to really see what the underlying cause was.

    I tell you this to help you understand that it isn't always black or white sometimes. :( If however, he did see mast cells under the microscope - than she had Mast Cell cancer. And clearly it was an aggressive type. She was just one of the lucky ones that was not feeling sick from it... yet. So try to focus on that... that she was feeling good and enjoyed her time with you - although too short.

    I'm sure Dr. Dana may also have an opinion on this but I wanted to answer you as well. I hope my opinion helped.

    Dr. Mary Gardner
    Lap of Love Veterinary Hospice

  3. Dear Claudia,
    It's never easy saying goodbye to a beloved pet, is it? Your terrier had a devastatingly aggressive tumor, unfortunately. Dr. Mary did a wonderful job explaining everything, not sure that I can add anything to her wise counsel. I hope this information has been helpful to you.
    take care,
    Dr. Dana Lewis
    Lap of Love Veterinary Hospice

  4. Hi Dr. Mary and Dr. Dana,

    I appreciate both of you reading my questions and educating me how mast cell cancer works. Dr. Mary, thank you for your thorough explanation of how mast cell cancer can affect your dog. That was one form of cancer I had never heard of. My dog Terri sounded much like your "scruff story". The couple times they aspirated her mammary lump, it didn't show anything but fatty tumor cells. But when the vet removed the first mammary lump, he said that it was very nasty looking, with tendrils and that he couldn't get it out completely. So it seems like at that time, he should have done a biopsy, and as with your patient, determined that it was cancer and in an early stage and start treating her. Since she had no treatments, I'm sure that it spread rapidly and reappeared in those 3 mos.....and had produced more tumors throughout her abdomen. She also seemed to develop a large mass on her shoulder blade, which seemed very solid....he aspirated it 2 days before her final surgery and said it was a fatty tumor (which I doubted) since it was very solid and didn't move around like a fatty tumor usually does. If I had known it was malignant, I would have skipped the impending surgery and just have her home with me until she got worse, then let her go peacefully with me and Lap of Love at home. The thought of her being put down on a steel operating table alone, without me, still breaks my heart! I have learned something from this sad experience, to have testing done immediately, if something is askew to prolong or save my pup's life!

    You guys are a special deal with sadness on a daily give peace and comfort at one of the most difficult times in a pet owner's life! Thanks again and again!!


  5. Hi,
    I just found this website and I wanted to see if I could get your opinions on treatment. My dog was diagnosed with mast cell cancer yesterday and I am at a loss on what to do. She has 3 tumors that have been diagnosed but upon bringing her home I found 4 more. The ones that were tested were on her back foot, hind quarter, and anal area. The hind quarter and anal one have been there for a year, as we were told they were just warts and terriers are susceptible to warts. She is an Ameican Pit Bull terrier. She is ten years old, turning 11 in March. The vet wants to operate and remove them but is that the wise way to go considering the quantity of the tumors? We had a major surgery performed on our other dog for cancer and we lost her anyway not even a year later. Please help!! Thank you

    1. Hi - I'm so sorry to hear about your dog. I know this is not easy.

      We all have different opinions on this matter so this is just mine. I am typically aggressive when it comes to cancer and if I can get 3 more month or even 1 year for doing something - I will take it. And nothing is 100% - but trying is worth it to me.

      I would make sure she has not other medical issues - like kidney or liver disease so that she can handle anesthesia (this is simple bloodwork) and I would have all mast cell masses removed (if there are some that are just warts - then I wouldn't touch those). (I would also talk to your vet about doing an abdominal ultrasound first - Mast Cell usually spreads to abdominal organs (vs lungs) and if it has already spread - I probably wouldn't do surgery).

      Keep in mind that with mast cell removal - the vet must make a large incision so the anal area may be tricky.

      I would then definitely have the samples sent out for histology so they can grade them and you can see how severe the disease is. There is a chance that it is a high-grade - especially because there are multiple masses in different areas.

      My own dog had a type of cancer. His surgery was VERY risky as it was to remove the tumor on his adrenal gland and he had a 30% chance of survival. But if we got it out - he had a 50% chance of it being benign. He made it through surgery (YAY) - but the cancer was bad - the malignant kind and it had already gotten to his liver. Without chemo - I would have had 6 weeks and with chemo 6 months. I went for 6 months and he did great with the chemo. At month 5 he declined but that was the cancer - not chemo. I loved every day of those 6 months.

      You can also seek the opinion of an Oncologist in your area. They may be able to give you a better idea of treatment options, statistics, etc.

      We have an oncologist who does phone consultations and that may be an option as well. Dr. Miller is wonderful and I consulted with her myself when Neo was diagnosed. Her information can be found on this page:

      I hope this was of some help to you. Again, I am so sorry to hear about your girl.

      Dr. Mary Gardner

  6. Thank you SO much for responding! I am still waiting to hear back about her bloodwork but I know they took two xrays yesterday as well. Would that pickup any problems in her abdomen?

    1. It depends on what part of the body they took xrays - if it was just her chest - then they are looks for mets in the chest..which is still good to do because it can met to the lungs - but Mast Cell USUALLY starts in the abdominal organs like the liver. And ultrasounds is best - you can evaluate the organs better vs with an xray.

      My Neo got ultrasounds every 2 weeks to measure the tumors in his liver.

      Bloodwork should be back quickly (next day) - so if she is ok for anesthesia - then you can think about it - but I wouldn't worry about anesthesia if kidney and liver values are ok. And if your going to remove them - the sooner the better.

      I recently found a Mast Cell on my other doberman and had it removed - luckily it was a Grade One and completely cut out. So I don't have to do any follow up treatment. The goal with surgery is to get them ALL out in their entirety PLUS some extra space.

      And some vets will want you to start giving benadryl - so if they haven't started you on that - maybe ask. :-)

      Good luck and we are all pulling for you and your girl!

  7. Thanks, just one last question. (sorry) my vet did not bring up performing an ultra sound and is only pushing for surgery. Her bloodwork came back good. Should a vet want to perform other tests before just opting for surgery?

    1. Oh it's 6 and one half dozen of the other - or however you say that! :-) I would probably do either way - remove them in surgery - send out for pathology and if they come back really bad grade - do the ultrasound. If they come back low grade - no point doing ultrasound. So both ways is fine. If you do ultrasound first and find ugly spleen and liver, surgery may not be best option (and I'd be at the Oncologist then).

      Or if your vet is good at doing ultrasounds (which I was not and we brought in a radiologist to do them at my clinic) and if all goes well during surgery - they can do a quick ultrasound afterwards while she is recovering.

      I just want you to feel comfortable that your vet is 'correct' - I would push for surgery too and the sooner the better. For my dog, we removed it, and since it was a Grade I - I didn't pursue ultrasound. I'm a little concerned that your dog has had the one for so long and so many. Makes things a bit more tricky.

      IF they come back as anything more than a grade I - I would highly recommend just seeing an oncologist to get the most up to date information for treatment options.

      I sure do hope I'm helping and not making you more confused.

      Here is another sheet of information we made too:

  8. Thanks again,
    Yes, she has had the one for a long time but it is the size of a wart so that's why we thought it actually was a wart. The others that have popped up are also the size of a small wart. Probably not even the size of a dime. None have become ulcers or open wounds yet. I just didnt want to put her through an extensive surgery if the cancer has infected her in places where the prognosis is not very good. Quality of life is my top priority for my old friend :)

  9. Good - I'm glad they aren't too nasty - many look like 'nothing' - which is why i ALWAYS recommend getting all lumps and bumps checked. :-)

    Luckily - skin mass removal is not that bad - it is not very invasive. The worst part is that even the small mass - needs to have 3cm circumference around it. But on the back or sides - that is no big deal - lots of skin. Near the rectum will be tricky but doable.

    If she were mine, I'd get them removed and see what we are dealing with. That way you know. The day after surgery she will be back to her self again - minus the horrible Elizabethan-collar! haha

    And I hope your old friend has a LOOONG time with you to become even older!

  10. So do I. She is scheduled for surgery so I hope that at least some of them come back as benign. ( I hope that is realistic to hope for) :)

  11. So do I. She has been scheduled for surgery so hopefully some of the tumors come back as benign.. ( I hope that is a realistic thought :)

  12. Good - please keep me posted! And they have not dis-proven positive thinking yet - so I'm sending you good vibes! And don't forget the e-collar - we don't need her chewing out any stitches.... unless they are in a spot that she can't get. But you know dogs - they can always lick their 'rears' ;-)

  13. Hello! Thanks for your great information. I'm hoping that you might be able to give me your thoughts on my cat.

    I have a nearly 17-year-old cat who is having an awful time with mast cell tumors. She originally had a small one removed from under her left front leg about 4 or 5 years ago. Then, last year, she developed a very large one on the back of her head; it popped up fairly quickly and she scratched at it until it was bloody. We had it removed, and the vet found a few small ones in other spots on her body during the surgery, so those were removed as well.

    Now she has them popping up EVERYWHERE. There is a very large one just to the left of her spine on her hindquarters; there are 4 or 5 fairly large ones on her back left leg; and a handful of small scattered ones all over her body. The ones on her back left side are so large, they look very uncomfortable, but they aren't bleeding and she doesn't seem to mind them.

    I don't really know what to do about them (we have a vet appointment soon). After the last surgery, we discussed excision, chemotherapy, and one or two other things in the event that they came back, but they're so aggressive now--I would be shocked if they could remove them, since they are more or less covering the entire surface of her back leg. She wouldn't have any skin left! I don't really want to put an elderly cat through chemotherapy, either--it seems very hard on her.

    There is another factor, as well, though it really hurts me to say it: her last surgery was very expensive, and we are still recovering from it financially. My husband and I are young and don't have a lot of money. It kills me to decide how to treat my sweet baby based on money, but we literally can't afford another $1k+ treatment.

    I worry that with how aggressive the tumors have become, we'll have to make the difficult choice to put her down. But she's still so lively and happy; I hate to do it when she's not showing any signs of pain.

    Do you have any ideas? Thank you so much for taking the time to provide this info and to read my long story.

    1. Hi Kate - please see Dr. Dana's response below - I hope it helps. I would agree with her about best treatment options given what you'd explained.

      Our thoughts are with you during this time!


  14. Kate,
    So sorry about your kitty! There is no grading system for kitties about how aggressive the tumors are-but the pathologist can say how many dividing cells they see, and obviously how fast they grow and how fast new ones occur tell us how bad it might be.

    Here are my thoughts:
    1) If it has spread anywhere internally, there is no point in doing surgery on the skin unless to keep her from digging at it.
    2) Options for treatment are:
    -surgery alone (with a flap or graft or only debulking some of the tumor)
    -surgery and radiation therapy
    -surgery and chemo

    -chemo alone, if it is everywhere on the skin and possibly elsewhere in the body (for cats we extrapolate from dogs: we think about steroids, vinblastine, ccnu, and maybe cytoxan. Palladia would be a last resort if you used the other drugs and they didn't keep her in remission)

    -palliative therapy-steroid (prednisolone in cats), benadryl (to reduce degranulation of the Mast Cells), and GI protectant (pepcid) to reduce stomach ulcers.
    while the last choice is least expensive it is also probably most practical in an elderly kitty who keeps popping up new ones.

    When to make the decision to help her transition is very hard to do. I would use our quality of life scale on our homepage at or our online version at which is an interactive scale and diary that you can update. These tools help you assess everything that makes life worth living for your furbaby. When the score declines, it gives you an objective way to see that the time is drawing near.
    Hope this was helpful!
    Dana Lewis, DVM

  15. Hi Doctors,
    Our 11yo male lab had very large mast cell tumor removed about 4 years ago from right rear leg. It recurred 2 years later and we again had it removed. We were never told a stage, only that it would continue to recur.Over the past several months, the leg seemed a bit weaker and several weeks ago he began to limp. Had xray this week and we've been told it is either osteosarcoma or fungal infection of bone. There is no swelling and is in the exact same part of leg as the mast cell tumors...could this be related of just coincidence? We are heartbroken, can you please offer some direction. He can't bear weight on it and we are managing his pain with rimadyl. Thank You!

    1. Hi - I'm so sorry to hear about your lab. I can't be sure if the mast cell is related to this new problem. Osteosarcoma is very different than mast cell and I am very concerned about him not bearing weight on it.

      To be honest - bone cancer can be very painful and if it is bone cancer - one day that may fracture and be extremely painful. I'm afraid Rimadyl alone will not give him enough comfort and I would suggest seeing if your vet can add pain killers (Rimadyl is an anti-inflammatory) - maybe something like Tramadal every 6-8 hours. If he is not bearing weight on it - it is painful. We may never really know what his issue is or if the two are related - BUT we can help manage his symptoms. I'm a strong believer in keeping them comfortable so his quality of life is still enjoyable.

      Curious - is it his front or back leg and is it close or far from the elbow/knee.

      Mary Gardner, DVM

  16. Thank you Dr. Gardner for your quick response. It is his right back leg, close to the knee, radiologist read xray as a lytic lesion. Externally,there does not appear to be any swelling, just more of a wasting of the muscle tissue. We are sending in a urine sample on 1/7 to check for fungal infection (I think he said pcr test), and I will ask vet about Tramadal for pain.

    1. Not sure if you got notified of my response/reply below. :)

    2. yes, thank you for your advice. We dropped off the urine sample this am to be sent for analysis for possible fungal infection? I also asked about the tramadol, as rimadyl didn't seem to be helping him much. Dr. prescribed 2 50mg pills up to 3 times per day, along with rimadyl 100mg am and 50 mg pm. This seemed like a lot so haved started him this morning on just 50 mg tramadol and 100 mg rimadyl to see how he feels. He weighs 90 lbs. He is diabetic and eats/takes insulin 2 x day, and I didn't want him to be too drugged as so not able to eat normally. Does this sould ok for treatment as we wait for the results for the fungal test? It could be several days before we have that test result. Feel so helpless, is there more we should be doing right now, other that pain management and protecting his use of that fragile leg??? Thank you!!!

    3. I would definitely start at the dose your vet suggested. It really isn't that much. My 50 pound dog gets 100mg 3 times a day and she is completely coherent. ;-) OH - and she is also diabetic. It probably wont make a change at all in his behavior - just make him feel better. And to be honest- that is the low dose. Maybe give it after he eats his meal and you give insulin so that you feel more comfortable.

      The 'half life' of Tramadol is 8 hours - meaning it is out of their system in 8 hours - so definitely giving it 3 times a day is advisable so that you aren't 'chasing' the pain every 12 hours.

      I think you are doing all you can do at this moment. Pain management is the most important and making sure he is gentle on it.

      Osteosarcoma does not have a good prognosis and I'm so very sorry. Just keep him happy, fed well and well loved. His eating may decline over time and with his diabetes, you need to be careful. But I am sure you know all there is about that.

      With my hospice patients, the ones with Osteosarcoma, I even prescribe one dose of strong injectable pain relief - that way - if the leg fractures - you can give that to him right away to ease the pain while you wait for the vet to come to the house or bring him to the vet. Since you are already comfortable with giving injections - this should not be an issue for you and may simply give you peace of mind if the emergency does happen.

      I hope this helps!

    4. Hi, I just wanted to give you the update. Our sweet boy does not have a fungal infection, and the radiologist read xray as probable osteosarcoma. We are trying to keep him comfortable with 100 mg tramadol 3 x day and 100 mg rimadyl 2 x day. Tried adding gabapentin, but it made him very restless and just wandered around the house panting for hours. Seems to be doing ok now, eating normally (plus some extra things he loves:)). Is there something more we should be doing right now? Will he let us know when it is time, or how do we know? Wish there was a Lap of Love vet in our area (western Illinois). Thank you so much, you've been a great source of information.

    5. Thanks for the update. I'm sorry that it wasn't better news. I had my suspicions but one can always hope. I am also sure you were told the statistics of osteosarcoma - they aren't very good. SO.... this just means EXTRA CRAZY amounts of love, TLC, treats, pictures, videos, etc.

      Many pets will pant, etc because of a level of anxiety they feel. See Dr. Dani's blog post on knowing 'when is time' as she talks about this:

      You may ask for some sedatives to give him at night - just to take the edge off and make sure he has a good nights rest. That way he is more alert in the day to have fun.

      It does take about 10 days for gabapentin to kick in and reach a state that he will 'feel'. So I would personally keep him on it - I think the panting, etc is just clinic signs from his cancer.

      We have two vets in Illinois but maybe not close to you. Dr. Dawnetta: and Dr. Juliana

      We also have something that may help you with determining his Quality of Life... it is the Pet Hospice Journal.

      You can put in daily/weekly notes, assess his quality of life, add pics, etc.

      Hope this helps. We will be thinking of you!

      PS - and please ask about the injectable pain med for the emergency situation. Ive seen some very bad situations happen and it is nice to have that on hand.

  17. Ok - well typically Osteosarcoma is closer to the knee in the hind leg and closer to the shoulder in the front let - but this is not always the case. Just something to keep in mind. :-(

    The muscle wasting is probably because he was/is painful in that leg and not using it as much as the other side - the left side is doing more of the work.

    Just make sure you limit his jumping activity - so NO couches, jumping into or out of cars, etc. The back legs are used more with jumping UP (the front are jumping down) - but limiting all jumping - even if he is having a good day - is a must. Think of that lytic bone like Styrofoam - very fragile.

    Keep us posted!


  18. I am so thankful to have found your site. I have been struggling for weeks to figure out how to proceed with my 6 year old cat's treatment options. He had a mast cell tumor removed from his back leg in late December; and although my vet removed it all, the margins were only 1mm given the challenging location of the tumor and the limited tissue sourrounding it. We then went to see an oncologist who did an ultrasound, xray, and aspirated the spleen and the lymph nodes near the tumor site, and all tests came back negative for any other cancer cells in those areas. One of the comments indicated that there was "lymphoid hyperplasia in the splenic aspirate", but I am not sure if that is something I should be concerned about.

    Anyway, the oncologist says that my little guy has a 25% chance of a local recurrance and if it does come back, it will be a much more aggressive cancer and she recommends that he undergo radiation therapy since the margins were so small. She indicated that a second surgery with a possible skin graft or amputation would have been the best option, but his other leg never healed properly from a pin that was placed in it and then removed before I adopted him a few years ago, so he cannot lose his "good" leg to surgery.

    Even though I have pet insurance that would cover a significant portion of the costs, I am not sure I can put him through daily radiation treatments given that he is a very anxious kitty, hates to be put in the carrier, and already has experienced a severely blocked urethra and related PU surgery this past year and also had a tough time recovering from the recent MCT surgery.

    Any insights or guidance you can provide would be much appreciated, as I am at a loss as to how to proceed - especially since I am not sure how his recurannce rate would be impacted by radiation therepay vs. doing nothing else at this point since it appears that he has no other cancer in his body.
    Thanks so much.

    1. Hi Katerina - I am so sorry to hear about the troubles with your little guy. It certainly sounds like you are a great mom and should be commended for doing such great research!

      I must say that as a general veterinarian, I always refer to oncologists since they do know the best course of action, most recent therapy options, statistics, etc. So I am glad that you are under the care of a good oncologist. :)

      So sorry to hear the tumor was in a tough spot that narrow margins couldn't be 'wider'. It is sometimes really hard based on location. And I can certainly understand that we need to keep his 'good leg'.

      You ask a very good question about his recurrence rate with radiation - humbly - I am not knowledgeable enough on radiation therapy.

      May I suggest a consultation with our oncologist? She is wondering and does phone or skype consults. :) I only suggest this because you are truly seeking options and have good questions. Here is Dr. Miller's page for more information (your insurance company may cover the cost as well which would be wonderful):

      Now - if you do decide on radiation therapy - may I suggest some anti-anxiety medication before hand. Something that would not interfere with any sedation they do at the oncologist. :) I know he has been through so much and low stress is important in any recovery. One more 'natural' choice I recommend people trying is Rescue Remedy - here is the link:

      This is not a sedative but does a nice job of taking the edge off. May be something to look into. And taking a car ride every day that does NOT entail going to the vet would be a good way to get him used to the car. And if they suggest benadryl - maybe giving that an hour before his car ride, would make him sleepy! ;-)

      To be honest, if it was my little one - I would talk to Dr. Miller and probably lean towards radiation - but I am one that is more aggressive with treatment. I like to get as much cancer gone as possible!

      Please keep us posted and our thoughts are with you.

      Mary Gardner, DVM

    2. Thank you so much for quick and very thoughtful response. I will plan to get in touch with Dr. Miller this week since it would be great to have another oncologist weigh in on the pros and cons of the treatment options available.


    3. Oh good - I totally agree - having as many 'smart' opinions is the best. I honestly had Dr. Miller consult with me after seeing my oncologist - it is a BIG decision.

      Until any decisions are made - lots of love and TLC for your little one! :)

  19. Great news!!! She is done with surgery and the results from her tumors were... 2 as grade 1, and the one on her foot a low grade 2. We had the bone tested on her foot and it came back clean. All the tumors came back as having clean margins too.I posted under user name "the list" not quite sure why it didn't for this one

    1. AWESOME news! YAY! So glad you did sx! And clean margins is great news!

      Thank you for keeping us updated!!!


  20. Please help: I have a 10 1/2 shih tzu. The vet told me that she had a mast cancer tumor. We didn't bother to do the aspirate needle b/c either way, we would need surgery to get it out. He said, most likely that it is cancer. We have no problem with doing surgery, problem is. Because she is small, (13 lbs) there is a slight chance that she will not wake up from surgery because of how strong the Anastasia. It's either she does the surgery and have a slight chance of surviving it.. If she does survive it, she will only live with one kidney, and the surgeon said that most likely the same thing will happen to her other kidney. The last thing I can do, is just take care of here until she can't take the pain. Is there anything I can do? Is it possible to reduce the mast, anything? I can't sit here and watch this happen to my baby.

  21. Very sorry to hear about the possibility of mast cell disease for your girl. I am wondering where this tumor is located as you say she will only have one kidney. A mast cell tumor is not a typical kidney tumor. If they think she has a tumor in her kidney, then removing it is likely to be curative as long as no cells have spread elsewhere. Removing the kidney and determining what kind of cancer and then giving her chemotherapy if indicated improves her survival even longer. The only way to tell if a tumor is made of mast cells is to take an aspirate or biopsy sample (either a small sample, or taking the tumor out and sampling the removed tissue). Her size and age do not put her at risk for anesthesia, however, if she has any problems noted on her bloodwork like kidney or liver disease, or if she has heart disease, that could cause her to be at greater surgical risk. If surgery is not an option, there are medications that can be given chemotherapeutically for cancers, radiation therapy depending on the type and location of the cancer, as well as a vaccine against mast cell tumors and other tumors called Palladia.
    I hope this helps,
    Dr. Dana

  22. Hello,
    I have a five year old Spaniel-mix who has recently been diagnosed with a mast cell tumor. The tumor appeared very suddenly -- the Friday before last I noticed some very, very severe bruising near a hot spot that he usually licks a lot. I didn't notice any swelling, but the bruising was so strange I brought him into the vet that day. After a FNA, the doctor came back this week and told me it is a mast cell tumor. Over the course of the last week the bruising has gone away and the tumor has swelled to the size of a chicken egg. His buffy coat was clear and blood count was normal, as were his chest x-ray and his ultrasound. When a tumor is near the genitals, and grows so fast and so large, does it even make sense to do surgery? The vet says yes, but I'm afraid to put him through surgery if he only has a few weeks anyway. Do you have any advice?

    Thanks in advance,

    1. I definitely would do the surgery to remove the tumor - it is best to get as much out as possible.

      Did you do it yet?

  23. I took my 11 year old lab today to the vet to have a skin tumor looked at. My vet palpated and examined the growth. She said it was likely a mast cell cancer and although the extruding part was not huge (looks like a big toe stuck to his hip), the interior part was quite massive. She believes the tumor agressive & malignant. As my dog is older and also suffers from seizures and arthritis, my vet recommended no treatment (anthesia would likely cause an uncontrollable seizure). I understand without full testing & pathology, her diagnosis is only an educated guess, but regardless, my dog is otherwise asymptomatic at this time & I would not want to put him through surgery & pain that may not cure his problem. Also, my husband is presently recovering from major cancer surgery & a stroke - our luck is not good and finances are already stretched tight. Any advice?

    1. I would want your vet to take a sample of the mass with a needle to see under a microscope what type of cancer it is - you cannot just 'feel' and know what it is. This way you can know what you are dealing with better. :)


  24. My 11 and half year old rescue greyhound has a lump removed from his shoulder recently which came back as a grade 3 mast cell tumour, his prescapular lymph node is swollen now too and the prednisone is not effective, he is taking zantac and antepsin which are helping. We have to make the decision to put him to sleep which we are finding very difficult, the side shoulder which is swollen does cause him some pain and discomfort in certain positions and he shakes and pants with the medication and is losing weight even though he has a great appetite. The lump which was removed is back already after a few weeks, is it time to let him go or keep him with us a while longer? Please help.

    1. I think the big question is how is your boy doing? Is he eating, having a good quality of life? If things are still 'good' - I would wait. We have a tool you can use for free to help with assess his quality of life "" Hopefully that will help.


  25. We have a 14 year-old female Yorkie-Poo that has a mast cell tumor on her right rear paw (between her far-right digit, and the next digit in). The tumor is steadily growing, although it isn't bleeding. She has her general 'spunk', eats well, and shows no sign of pain (currently).

    She has been on chemo for 5 weeks, however, it has not helped. We have been given two basic options: 1.) Surgery (possibly amputating the leg, 2.) Letting her live out her remaining life.

    We have two questions in this very difficult time for us:

    1.) What do people generally do in this scenario? Is it good to amputate the leg of a dog at this age? Will her wounds ever heal?

    2.) What type of scenario would she go through if we didn't amputate? Would she start feeling pain (ulcers?)? How long would a dog in her current condition generally live? (given that the tumor is growing)

    Thanks for any help or insight during this difficult time.

  26. We have a 14-yr old female Yorkie-Poo that has a mast cell tumor on her right rear paw (right between the far-right digit, and the next one in). It is quite large and steadily growing. We are working with an oncologist, and she is on chemo; however, it has not worked. The tumor is still growing, although it is currently not bleeding. The tumor is already in her lymph node higher up on her leg. She has her ‘spunk’ and is eating well with no signs of pain.

    We have been given two options: 1.) Surgery to remove either part of her foot, or her entire leg, or 2.) Let her live out her remaining time.

    What should we do? Do people normally have surgery on a 14-yr old dog? Will she survive the pain and healing?

    Or do people normally let her live out her time? What type of phases would a dog normally go through from here on out? When would we know when to put her to sleep so she doesn’t feel any pain (from ulcers, etc.)?

    Thanks for any help or insight into this difficult time.

    1. Hi Kevin,

      I'm sorry to hear about your girl. It is in a difficult location for surgery and hence that is why they need to be so aggressive.

      I personally don't know what the right option is. I wonder if Radiation Therapy might be beneficial?

      I would suggest a consult with our oncologist via phone or skype - she can read all the medical records and make a more educated recommendation than I can.

      Here is information on Dr. Miller:

      Dr. Mary

  27. Hi Dr. Gardner,

    Our 10 year old beagle very recently finished 6 rounds of prednisone and vinblastine treatments for a mast cell tumor (stage 1) at the base of her ear.

    When we first took her to the specialist, the tumor was too large to be removed with margins. By the end of the treatments, it had fully disappeared, and surgery was ruled out a second time.

    It is now two weeks since her last treatment, and today the tumor has reappeared and is very large. We haven't even had her recommended three week check up yet. Is there any hope here? It seems the treatments did nothing, we're back where we started, and the same outcome seems inevitable: it'll be too large, then too small, to operate, and treatment only won't work.

    This is very discouraging. Any recommendations you might provide are greatly appreciated.

    Thank you.

    Aaron Smith

    1. Aaron,
      If you are not talking about her with veterinary oncologist, I would do so. Perhaps radiation therapy is indicated here. Again, an oncologist is your best bet. If you are unsure about your options, consider a consult with our Dr. Karri Miller.
      Dana Lewis, DVM

    2. If you are not consulting about her with a veterinary oncologist, I would do so. Perhaps radiation therapy is indicated here. Again, an oncologist is your best bet. If you are unsure about your options, consider a consult with our Dr. Karri Miller.
      Dr. Dana

  28. Good afternoon Dr. Gardner & Dr. Lewis,

    My two year old lab mix rescue (mixed with either boxer or pitbull) was diagnosed with a mast cell tumor in December 2012, and I had it removed immediately (Grade I). It was located on her chest close to the under "arm" of her right front leg. Today (3 months later), I found another small bump (almost the exact same location, but near the left front leg). I am prepared to remove this one as well, but I am concerned because I cannot afford to remove these masses if they continue to appear this frequently. At my last veterinary appointment (February 2013), when she was given her annual vaccinations, the vet said it was imperative to remove any lump I find on her immediately. Based on everything I have read, this is a very young age to be dealing with mast cell tumors. Is there anything I can do to prevent or to delay future reoccurences? Should she have been on prednisone after the removal of the first tumor and would that possibly help to delay another tumor? What kind of prognosis would you give her?

    I thank you so much for any information or suggestions you can share.

    Deborah Lee

    1. Deborah,
      I would definitely be talking with an oncologist about your girl. I am not an oncologist,but I do see quite a few pets with cancer as a hospice veterinarian. Perhaps Palladia might be indicated? You might consider a consult with Dr. Karri Miller
      Unfortunately, we cannot tell from just looking at a lump whether it is cancer or not usually. You can have most lumps assessed by having a fine needle aspirate done and having the cells examined. And if we suspect cancer, we cannot tell how aggressive it it until it is biopsied and examined under a microscope. If you have her lumps aspirated and keep a chart of her body for each one and when it was aspirated, what it was determined to be and what size it is, you can follow along with them. If they start to grow, reevaluate or remove them. I am glad you are being her advocate for these lumps and I wish the both of you well. Dana Lewis, DVM

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  30. Dear doctors,
    We have an 11 1/2 year old golden retriever who I dearly love. About 5 months ago I noticed a bump on his hind leg. The bump got bigger (about the size of a baseball). I made an appointment to take him to the vet and in the meantime he opened up the womb and hollowed it out. The vet looked at it and suggested that I have surgery done. We took him to a great vet to perform the surgery and it was very dating financially on my family. Just about 3 weeks after that I started to notice bumps reoccurring in the same spot. Now the bump is as big or if not bigger than the original bump. I to him to the vet and he said that I can wrap it until it gets too big or put him down. We can not afford radiation and the vet thinks it wouldn't work anyways. I am having a hard time with this because he does not have any cancer, just this cyst. I have noticed that it is harder for him to walk and I have him on remidyl. I do not want him to be in a lot of pain but can,t stand to part with him. What do you suggest?

    1. HI - well, one can never be sure that all the bumps are cysts. Every bump should be checked. I have had one patient that had 22 bumps and they all looked like fat... but 2 came back as cancer. So it is something I suggest all clients to have checked - but I do understand the financial aspect of it. I agree with you and we want to make sure he is comfortable and not in any pain. Rimadyl is an anti-inflammatory - I may also ask your vet for a pain killer like Tramadol. Together they may help him out a lot more! :)


  31. Hi my 7 yr old spayed tibetan terrier had a sausage sjaped lump on her boob we took her to the vets they said it was an abbcess put her on antibiotics on return the week after it had changed shape and gone solid they advised surgery yook her the same day to another vet they advisex surgery as they thought it was a mammory mass today shes had the operation they said it didnt look like a normal mammory mass and it was badly infected its been sent off for testing i get the results on monday her chest x rays were clear im very worried its cancer what do you think!

  32. Hi:
    Hoping for some realistic advice. My 9-year-old Boston Terrier was just diagnosed with a mass cell tumor on her foot pad. About 6 months ago she developed a lump. I took her to my regular vet who thought it was an infected foot pad. We treated it with steroid powder, antibiotics and dressing it/keeping it clean. The swelling went down a little bit but it came back about a month ago. I took her back to him and he referred me to a surgeon - it was now quite large "raw" looking. I saw the surgeon last week and he did a needle aspirate of the lump itself and an enlarged lymph node in the hindquarter of the leg that is involved. The tumor is quite large and raw looking - on the bottom of her foot which makes it quite tricky to do surgery. I honestly cannot afford the $2,000 surgery and am really struggling with this. Is there a chance the tumor is not malignant?? Since she's been living like this for 6 months, could she continue for some time? I just cannot afford to do surgery and end up maiming her! We are talking about a significant amoutn of her foot that would have to be removed. She has a heart murmur also which makes me nervous. I don't want her to suffer but I'm just at my wit's end as to what to do. Advice welcomed!

    1. I am sorry to hear you are in this situation. It is really almost impossible to tell you if it is benign or malignant at this time and mast cell tumors left on the body - is typically not good. I wonder if radiation is a better option for you?

      I would maybe see an oncologist first to get their opinion. We have an oncologist that does phone consultations

      but I think one that can see the foot in person would be best. They can give you the best answers over any general vet (like me) or surgeon.

      Either way however, it will be expensive. But I would speak to the oncologist to see if there is something less invasive that you could do or any medications that could help slow the process down.

      My thoughts are with you,
      Warmly - Dr. Mary

  33. Hi -

    My Am Staff mix, who is supposed to turn 14 in August, was just diagnosed with a Grade 3 mast cell tumor with an extremely high mitotic index (over 10, as I understand it - haven't seen the cytology myself). The tumor, which was very, very large and ulcerated, was excised from her back and right flank last Tuesday. For some reason, the pathologist has yet to report on one of the margins, but all other margins are supposedly clean, even though the surgeons were able to get only a 1cm margin around the tumor. A laparascopic liver biopsy done at the same time shows hepatitis, not mast cell cancer. And the internist believes that her splenic tumor, discovered in the course of the pre-op work for the mast cell tumor and showing as benign on aspiration, is likely also not mast cell cancer, as he says mast cells are generally pretty easy to get in an aspirate. (I elected not to remove the splenic tumor despite the risks even from a benign tumor and to remove only the mast cell tumor and do the laparascopic liver biopsy because at her age with her various issues, I was concerned how she would respond to abdominal surgery in addition to an invasive skin surgery, which ultimately required an incision from one side of her back to the other.)

    The mast cell tumor was visibly painful the night before surgery (although oddly, the morning of, it seemed less so), and she was doing so well until yesterday, that I was really glad we did it. I am still glad we did the surgery, but my happiness is now tempered by the news of the tumor's aggressiveness, and that yesterday, her symptoms of gastric upset got far worse.

    She has been on benadryl and prilosec for the last 3 weeks to counteract the gastric effects of the tumor, but she has thrown up three times since early evening yesterday. It seemed related to my having just given her the benadryl pills, without food, but previously, pilling her did not have this effect. I would be happy to put the pills in food, as that works if she's hungry, but if she's not hungry, she still needs her meds - which means pilling. And aside from the vomiting, she just looked so uncomfortable starting yesterday afternoon - at one point, she showed some interest in her food bowl but then burped and appeared to have some regurge, and just turned around and slinked back to her bed.

    Are there other meds and supplements I can give her in addition to the Benadryl and Prilosec that will be more protective of her stomach lining than Benadryl and Prilosec alone? I want her to keep her meds and food down.


    1. Hi Emme,

      Ugh - Mast Cell Tumors can be so nasty and I'm sorry the grade was so high in her girl. The Benadryl is more to hep deter the histamine (which the Mast Cells Produce) from being released - the Prilosec is of course for her belly.

      Feeling nauseous is the worst. I think back to when I am sea sick - just the worst. Your vet may be able to give her an anti-nausea medication that can help.

      I also usually prescribe Pepcid AC so ask your vet if you can switch to see if that also helps.

      We also have an oncologist who performs phone consultations and can review your pet's chart/biopsy results, etc. Here is her page with information:

      I hope this helps some and you are in my thoughts.

      Dr. Mary

  34. Hi-

    Our 7 year old cat was just recently diagnosed with Mast Cell Tumor (he had a large lump under his arm for a while that would go away and come back), and finally early June we had it removed and biopsied-- it came back Grade III. He is now having new ones pop up all over him and he seems ok, but slowing down (not sure if it's because of the med's we started him on).

    He eats normally (he's a little overweight anyway), and the vet that performed the surgery didn't really have much knowledge on the issue. My husband is a resident physician so he had some good questions to ask, but right now we are only giving him the 0.4 predisone 1 x daily with the 5 mg pepcid and 12.5 bendryl 2x a day.

    He's my buddy and it stinks. But my main concern now is that he isn't suffering. We would like to do more, but really have no insight, and with new ones popping up, it seems that we aren't sure if it's internal/or when to know what to do. He's still young. We had not brought him to the vet because he turns rabid when he gets there (basically a whole different cat), you wouldn't know it if you came to the house. Anyway, do you have any other information for us? Suggestions as what you would do if any? The new lesions seem to be getting bigger, which makes us concerned that he is in pain? One is on his lower lip, and he's forming one in the corner of his eye as well as around his ear. The rest are all over his back and stomach area but start as small bumps. It's not fun and it just started getting worse over the last couple weeks.

    Anyway, any insight as to what you would recommend. We don't really want to pay a ton of money, but would like to know if we could have him around a bit longer and if so, how long do you think it would be?? He hasn't thrown up or anything and he's a normal eater, he's been sneezing a lot, but I believe it's allergies.

    Sorry for the rant, but I saw this sight and seemed very helpful.

    Thanks again. Look forward to hearing from you either way.

  35. I'm very sorry to hear about your boy, Lauryn. I would strongly suggest a consult with an oncologist for your kitty. I do know that internal mast cell tumors are a much larger worry for kitties than skin MCTs. I am not sure of the success of Palladia for cat MCTs but that might be an option. These other lesions do need to be assessed to see if they truly are MCTs. I hope your kitty does well with whatever therapy you choose and that the quality of life stays high for a long time to come. Dr. Dana

  36. There is a dozen natural cures for cancer. My dog (9 year old, 90 lb. black lab)had prostate cancer and could not go to the bathroom. I had to squeeze his bladder for 2 weeks while I gave him 50 1000mg of liposomal vitamin c a day 5 every 1 1/2 hr.(Nothing at night). He is fine now. Goes to the bathroom on his own.

  37. I love this blog. So much useful information. I am hoping you could give me some advice. I just brought my 10 yo yellow lab to the vet for a suspicious growth on his hind leg by his knee. The growth is less than a dime size but has me worried that it is a MCT. The vet took a needle aspiration. I should have results back tomorrow. My fingers are crossed!! My question for you is, he has a handful of what the vet (different vet) previously called benign lipomas just under his skin. If the aspirated mass shows MCT cells should I request that the lipomas also be aspirated to make sure the others are not MCTs? Thanks in advance for your help.

  38. My dog Starr, a Bichon/Shitzu cross had a lump on his belly which we thought was a fatty lump. We watched this lump for a couple of years and then it changed shape.We decided to have it removed. When the results came back it was a MCT grade II. At that time we lived in Calgary and were lucky to live 10 mins away from Western Veterinary Specialists which has a Veterinary Cancer Centre. After staging our dog had a course of 18 radiation treatments overseen by Dr Neil Mauldin. That was over 2 1/2 yrs ago. Starr has just had his 15th birthday. There is now available SRS Stereotactic Radiosurgery,with this the tumour is not removed surgically but by radiosurgery. The treatments can be done in 3 treatments over 3 days. If you are lucky to live near a Veterinary University its worth investigating whether they do this type of treatment.

    1. Linda - I am so happy to hear your story! The one thing I would like to point out is that ALL tumors/bumps should be examined. I had one patient that had 10 fatty looking bumps and we took a sample of each one... 2 came back MCT. So you can never tell. And it was great that you guys watched it so carefully and removed it when you noticed a change.

      Thank you for spreading the word about the new types of treatments.


  39. My 5 year old min pin mix was recently diagnosed with MCT. She had a small bump on the backside of her ear, which was surgically removed. Results came back stage 1 with clean, but narrow margins (2mm). She is now 4 weeks post surgery and everything has healed nicely except for a small area on her ear opposite of the tumor location. My vetbis recommending a second surgery to remove a larger portion of her ear as he does not see any signs of tissue granulation. Any advice or suggestions would be greatly appreciated. Thank you!

  40. Jen,
    well, that is good it is a stage 1, however, those are pretty narrow margins. I am not sure what your vet is seeing that has him concerned, but better to be safe with larger margins, than sorry if it grows back. But if this is a totally new area, he could do cytology on it to see if there are mast cells present. Either way, have it checked out. Dr. Dana

  41. My 8.5 year old rhodesian ridgeback has had two surgeries to remove mast cells. The first removed several small masses in her hind leg. It came back as a low grade 2 with a mitotic index of<1. The vet did not got clean margins. I opted to have a second surgery to obtain clean margins and also another smaller mass that had been on her side for about 4 years that turned out to be another mast cell. It was small and benign looking really. There was no sign on mast cells in the leg and clean (3cm) margins on the new mass however it came back as a Grade III with a mitotic index of 0-1. She has no signs of metastasis and has had an ultrasound, spleen biopsy and liver tests. She is a perfectly healthy dog as far as I can tell-great appetite, lots of energy although the benadryl seems to make her a little drowsy. My oncologist is recommending chemo therapy for 2 months but I am hesitant. I don't understand the grading of a 3 with a mitotic of <1. In the literature most grade III's have a higher mitotic >5. I also found a paper in the literature that suggested a more mature tumor was likely less aggressive (Bostock. D.E)

    Would you be able to comment at all on cases you may have seen? I am a scientist (physical chemist) and not a doctor but the data seems a bit foggy when you have a grade III with such a low mitotic.

    Nicole and Pumpkim

  42. Dear Nicole, I would say that your oncologist has a reason for wanting to do the chemotherapy that I am not aware of. Since I do not have the full biopsy report and also and not an oncologist, just a cancer nut, I cannot really guide you on this. Perhaps they did c-kit eval of the tumor, or special stains, or any number of other things that makes them worry and why they graded it higher even with lower mitotic index. Please ask your oncologist to explain their reasoning on why to pursue chemo. Again, chemo for pets is not as stressful nor debilitating as for humans. If your dog doesn't mind going to the doctor, I would seriously consider doing it if that is what oncology is saying to do. Thanks for reading us! Dr. Dana

  43. Hi,
    My 11-year-old crossbreed was diagnosed with Mast Cell cancer in August 2013.

    The lump, which we now no is MCT, had been present for one year. Previous Vet’s had advised this was a fatty lump.

    Upon requesting an aspiration of the lump (on his hind left leg/foot) the MCT was discovered. Surgical removal was carried out, however, the surgeon advised the lump was ‘very aggressive’ and was ‘likely to return’. Also, the surgeon was unable to remove the entire tumour due to location.

    The year leading up to the discovery of the MCT, my dog was often passing blood, being very lethargic and vomiting for a few days at a time, every week or two. On each trip to the vet – these symptoms were put down to a sensitive stomach and the relative medication was given.
    I now understand that this was a systemic symptom of the MCT.

    So five months on from part of the Mast Cell tumour being removed, the tumour has re-grown, this time it’s grown wider and longer – not so much of a round lump as it was before. The area is always quite warm, like you would have in an infected area.

    He has had two very sickly-episodes since the part-removal of the MCT, which included, passing large amounts of blood when trying to go to defecate and vomiting, luminous yellow bile with and without blood. He is also, continually itching. We have tried anti-histamines, which have not helped. He seems very tired during the day, however is always happy to go for a walk.

    Last week we returned to the vet’s as his left popliteal lymph node (same leg as the MCT site) had swollen up – it is the same size as my hand. (palm and fingers) The vet had the lump / node aspirated, however, couldn’t see any cancer cells.
    The leg is slightly restricted, however doesn’t appear to be causing any pain – yet and he can still jump into the car etc.

    I do not particularly want to put him under general anaesthetic to have the lump / node biopsied, due to the stress it will put on his body.

    Could you recommend any other diagnostic checks, which are non-stressful (for my dog) also, in his condition, life expectancy?
    I was advised by my vet, he could have weeks – months left – however, he is eating fine, walking mostly ok, apart from a few limps (on the MCT leg) here and there, although nothing he seems bothered about.

    Many thanks


  44. Dear Rachel.
    I am so sorry for you and your dog! Sounds like an aggressive tumor based on the side effects he is experiencing and probable local metastasis to the node, but the definitive thing would be histopathology results.

    What they are looking at with MCTs to determine if it is a baddy or not are these things:
    1)staging-is there metastatic disease present already and then after surgery to remove the mass, are the margins clean and by how much?, 2)What is the mitotic index (how fast are the cells reproducing?),
    3)There are 2 grading systems in use now. Grade 3 is always bad, Grade 2 can go either way, grade 1 are usually easily dealt with. The other system grades them high and low. High is worse. and is the Michigan State University grading system classifying it as high or low?
    4)Somewhere between a third and a half of MCTs have this mutation called c-kit. Also, the histopathologists can do special staining to see what pattern is there-pattern 3 indicates a more aggressive tumor as well.

    So, if you have just a local tumor with clean large margins and it is classified as grade 1 or low, you are probably going to be okay.
    If you are graded 3 or high, its a poorer prognosis, and treatment will be aggressive and time will be short.

    Grade 2 - vets hate to hear grade 2. So, if you have the low high classification for grading as well, that is important. If you have c-kit testing and special staining that is important information, too. This information helps with prognosis and treatment planning.

    If there is metastatic disease, that changes treatment plan as well, since you while you might be able to remove some or all of the disease surgically that you can see, it indicates there's stuff you can't that will start growing.

    For c-kit mutations, there are medications that interfere with these tumors, and Palladia is one of them. Sometimes a more aggressive surgery needs to be done if there is local disease recurrence but again, has it spread? This requires aspirations of nodes sometimes several times, or biopsy of nodes, ultrasounds of abdomens, chest x-rays, etc.

    So if you aren't seeing an oncologist, you should take your boy to one to discuss what now? The tissues submitted before can be assessed again. More staging (evaluation for spread) needs to be done. Then treatment planning-chemo, palladia, local radiation, etcetera. I know chemo sounds intimidating, but pets handle it waaaaay better than humans.

    I hope you have a long time with your fur baby still.

    Kind Regards,
    Dr. Dana

  45. Hi Doctors!
    My 8.5 year old pit bull mix was diagnosed with a grade 3 MCT in Oct 2013. She had had the lump since July 2013, but we didn't get it diagnosed until Oct. It was very large and aggressive on her shoulder blade. Before we had it surgically removed, the ultrasound came back that it had not spread to any major organs. When we had it removed the margins we just ok, and the vet said that it had local lymph node involvement (the vet also remove one her lymph nodes). After surgery, we changed up her diet, started her on a form of chemotherapy - Lucurtan (sp??) and steroids and also started her on many different holistic treatments. She was doing so well until we felt the lump come back in the same place recently. It is a very small lump at this point, but we are pretty sure it is another MCT.
    My question is, do we try to surgically remove it again and put her through surgery again? How many times can we keep removing the same MCT? Or can we change up her meds to possibly slow down the tumor growth?
    We knew that the grade 3 MCT prognosis was not a good one, but she has so much energy still and we feel like she has so much life left!
    Any extra time with her is beneficially in my mind, so just looking for some advice!
    Thanks for your time!

  46. Gina,
    Sorry to hear about your girl. If you are not going to an oncologist, I would ask for a referral to one at this time. I strongly suspect that they will recommend taking a much larger surgical area, both wider and deeper removing the entire original surgical area and potentially step up her post-op protocol. The tissues should be submitted to Michigan State University so that both grading systems and c-kit mutation evaluation can be done if needed. This will help them tailor her treatment plan. I hope that she is with you for a long time to come.

  47. My pug is 13 1/2 years old and has had a past with mast cell tumors but they were always small and were successfully removed surgically. The last tumor she had was in 2009. Today she has a mast cell tumor ping pong ball sized on her chest. I am at a loss at what to do, she is old and I am afraid to put her through surgery due to possible anesthesia complications. Please help me decide whether i should put her through surgery or leave the tumor alone and just treat it with tegamet and benedryl. As of now i plan to give her tegamet to reduce its size and then make a final decision. PLEASE HELP!

  48. My pug is 13 1/2 years old and has had a past with mast cell tumors but they were always small and were successfully removed surgically. The last tumor she had was in 2009. Today she has a mast cell tumor ping pong ball sized on her chest. I am at a loss at what to do, she is old and I am afraid to put her through surgery due to possible anesthesia complications. Please help me decide whether i should put her through surgery or leave the tumor alone and just treat it with tegamet and benedryl. As of now i plan to give her tegamet to reduce its size and then make a final decision. PLEASE HELP!

  49. Dear Sierra,
    very sorry your pug keeps popping up mast cell tumors. at her age, unless she has heart disease or metabolic disease, she should be okay with anesthesia. how did she do with previous surgeries? does your vet feel she is a good anesthetic risk? If you elect to not do surgery, consider alternative medications such as steroids or NSAIDS, or Palladia if any of her previous tumors were higher grade. The Tagamet and Bendadryl reduce the risk of histamine release and gastric acid secretion that tends to be higher for mast cell dogs but they do not target the tumor cells to kill them in any way. Thank you for your comments and I hope your girl does well for a long time.

  50. Our 10 year old shepherd/hound mix had extensive surgery for an acute mucocele gallbladder. He required a J-tube for a while afterward and he remained in a fair amount of liver failure even 3 years later. He gradually developed several callus looking masses that we were told were benign. One started bleeding and, long story short, was eventually diagnosed as a Mast Cell Tumor. He was evaluated by a surgical specialist who said that, while he might be more comfortable with the mass removed, because of its location on his leg they would not be able to get good margins so surgery would likely not be curative. He later had a lymph node biopsy that showed nothing but an abdominal ultrasound that showed masses in the liver and spleen. We did not opt for surgery put him on prednisone. Within about 6 weeks he became critically ill and was found to have severe liver failure, pancreatitis and gastric ulcer. We switched him to just benadryl to keep him comfortable but, 4 months later, he is now developing multiple hot spots (as well as comedones and alopecia) on his chest and abdomen. He just seems to itch all the time. I dread taking him in to the is just never good news. We know that he is terminally ill, but don't know what usually actually brings about the end in dogs with mast cell tumors. I should also mention that if we give him a full dose of benadryl he sleeps so deeply he must stiffen up as he will walk like he can't feel his back legs for sometimes several hours at a time. His back paws slide and sometimes he will actually flip his feet upside down, walking on the tops, and not seem to notice. This dose eventually resolve.

  51. Dear Maggie Lynn,
    Your fellow sounds like he has had a tough row of it. It appears he is developing a neurologic issue with his hind limbs-all that knuckling and sliding indicates he doesn't know where his feet are as the messages are not being processed through the spinal cord properly. Mast cell tumors can lead to failure of the organ they are in, bleeding from organs they are in, gastric ulceration, and strain on the heart due to release of chemicals from the mast cells, among other side effects. Have you used a Quality of Life Scale to assess how he is doing overall? I would suggest you go to our website and under the drop down for Quality of Life there is both the Pet Hospice Journal and the Quality of Life Scale. Either tool will help you determine how much joy he is having. Kindly, Dr. Dana

  52. He comes out as an 8 on the scale. We did take him to the vet and he is now on a different antihistamine (atarax) and an antibiotic. The atarax doesnt seem to work as well as benadryl but also doesnt seem to lead to as many problems walking. We noticed problems in his mouth, and feared more tumors, but apparently it is pretty severe tooth decay and gum disease. We will see if the antibiotic helps that. They are afraid to sedate him for cleaning. This was the first time our vet didnt immediately go into how there was no need to consider euthenasia. When she saw the elaborate 45-60 second process he goes through to move from standing to lying she admitted he is likely in more pain than he lets on. Pain meds arent an option, though, as historically he hasn't been able to get from lying to standing on his own at all after a dose of tramedol. One day at a time.

  53. Maggie,
    So I assumed that he is on the antihistamine to reduce the likelihood of mast cell degranulation. If he is on it for other reasons, please let your vet know that the atarax isn't working as well. I would ask your vet also why they feel he is an anesthetic risk for cleaning and extracting any teeth necessary. Do they feel his liver is that compromised and can they use a protocol less metabolized by the liver? As far as pain control, if you don't have him on prednisone or another steroid, then perhaps they can put him on an NSAID? Thank you for taking such good care of your boy. I hope this information helps you and your veterinarian determine the best course of care for your dog. Dr. Dana

  54. Our 8 year old Min Schnauzer just underwent his 3rd surgery for MCT. He had a lump on his abdomen for about a month, the vet determined it was a MCT and removed it with what he considered good margins. Labs came back that margins were clear. Six months later, he had two more lumps, one on either end of the initial incision. Surgery was done again to remove these. Labs came back that the forward one did not have clear margins, so 3 weeks later, another surgery was performed to remove more in that area to be safe. All results were grade 1. I just discovered another lump about the size of a quarter forward of the last surgery. He heals wonderfully from the surgeries. At this point, I feel like the vet is doing his best, but it's not working. He is so young but at what point do we say enough is enough and stop putting him through surgeries that aren't working? What will his future be like without further surgeries?

  55. DJ-
    While grade 1 are considered fairly "benign", you never know that the next one is grade 1. More tests can always be done on the samples to make sure they are not of a higher grade. I would go for a consult to an oncologist regarding your schnauzer.

    Dr. Dana