Mast Cell Tumors in Dogs: some advances in conventional care
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Updated: May 6th, 2019
Hi! I have been getting feedback about mast cell tumors and I would like to get some info out there. I will focus on some conventional medicine advances for the time being that should be thoroughly checked into by dog lovers interested in mast cell tumors. These are not general cancer recommendations, rather just a window to full spectrum care, which is a phrase I coined to describe evidence-based selection of cancer fighting weapons from any source. I will focus on Western (allopathic) viewpoints today.
First, the traditional treatment is surgery…get ’em out. I wrote about pre-treatment with Benadryl before surgery, in a previous post, so remind your vet. Have any mass aspirated (needle biopsy) before surgery to diagnose most mast cell tumors so your vet surgeon has a general diagnosis before surgery.
Chemo consists of drugs like prednisolone, vinblastine, and others traditionally. Chemo in dogs is tolerated better than in humans as lower doses are used for cancer. The word “chemo” has a bad ring to it, but this is a prejudice developed from human medicine. Dogs generally handle it better, on the average, although everyone is different.
Note: if you have a Collie or related breed, make sure your vet tests for a MDR-1 gene mutation common in these herding dogs. This genetic issue may increase chances of side effects not only from vinblastine (above), but also vincristine and doxorubicin. Doses of these drugs shoud be lowered significantly if your dog is positive on this test. For more information, see the post on 8/30/08.
Predisolone or prednisone (“pred”, ) are cheap, common, side effects are most often not too bad, and they are tablets so you can change the dose easily depending on your dog’s responses. Vinblastine is a stronger chemo vinca alkaloid chemo agent, more potent than pred, which requires the dog to be in the hospital for injections. Some oncologists like cyclophosphamide and L-asparaginase (you’ll get different opinions and preferences from different oncologists). These are all used for mast cell tumors.
Some stats for Grade 3 mast cell tumors treated with surgery, pred, and vinblastine: At 1 year after surgery, 57% of dogs were still alive, and at 2 years 45% were still alive. Average remission times are about 10 weeks to 5 months with surgery, prednisolone, and vinblastine. Remember, every dog is different, however.
Radiation is used for mast cell tumors that are difficult to remove completely, or any grade 3. This can be high voltage radiation, or brachytherapy, which involves the use of radioactive implants within the tumor site. Yes, a little weird, involved, and costly, but long remissions in the literature.
For more helpful information and tools on Mast Cell Tumors, get a copy of the Dog Cancer Survival Guide
Many are not into invasive care, so take a look below:
One that should be considered for a less intensive protocol is Lomustine or CCNU. This drug has gotten a lot of attention in the last couple of years for good reason. It is a pill,and can be given every 3 weeks. Pretty easy and non-invasive, unlike most chemo protocols, and is a single agent so it is simple. About 40% of dogs with mast cell tumors respond to CCNU all by itself, which is pretty darn good.
Cimetidine should be used in dogs with mast cell tumors, especially those with decreases in appetite or vomiting. This is an antacid which kills two birds with one stone. Mast cell tumors cause excessive acid production in the stomach when they get bad, which cimetidine counters. Additionally, cimetidine has some good anticancer effects that have nothing to do with acid stomach. Finally, it is cheap and easy to get.
Ask your vet about intralesional triamcinolone. They may have not used it before, so do not be surprised, but they can access the info easily (1 mg per cm q 2-3 weeks SQ). It is an simple injection of a form of cortisone that most vets will have sitting on their shelves. It is not very expensive, and very common. Every 2-3 weeks, your vet can inject the mast cell tumor, or infuse the area where the mast cell tumor was removed, with a small dose of this drug. The direct contact of the triamcinolone with any mast cells left in the body will blast them pretty good.
A new drug called SU 111654 (great name eh?) is being worked on at Michegan State University. Looks promising. There is also a technique out there consisting of injecting the mast cell tumor sites with deionized water. Cheap as dirt, but mixed reviews.
This post is just a piece of full spectrum cancer care for mast cell tumors folks. There is a lot more, but I’ll let you sink your teeth into this…
Best to all,
Dr Dressler
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Dr. I desperately need some advise. This will be short and to the point. My male sheltie who just turned eleven the same day as we brought him in to the vets with vomiting and bloody stools and loss of weight. From blood tests he had eights times the normal liver enzeyme levels. He was put on medication for three weeks in which he took his medicine, ate only meat, pasta and not a large amount. He came in for his three week checkup which the doctor stated that the liver takes a while to get well for she thought he may have a diseased liver.
He was playing freesbe and seemed back to his old self and was shocked when she told us that some of his levels stayed the same but one actually increased a large amount.
An ultrasound was suggested which we had done by a board certified vet who took a needle biopsy of liver and pancreas which from the ultrasound had a spot on the pancreas but the liver was enlarged.
Sadly the report came back from a cytology lab offsite that all tests pointed in the direction of cancer of the pancreas but not a definite unless a histology report with surgery and that even was 100 percent.
We have both lost our jobs but want to do every thing we can to help our boy.
My question to you is can anything be done with such a rare fatal disease as far as the K-9 Immunity and Transfer Factor I have been reading that has dramatic results in cancer dogs. I am discourged for I haven’t read any blogs about a dog with pancreatic cancer recovering.
We have limited funds and didn’t want to purchase medicine that would do nothing.
I can tell you that I believe in miracles and even though the doctor gave him a couple of weeks to live he looks like a dog who isn’t even sick. He did vomit for the first time two days ago since we brought him in for the first time which really made us sad. The vet who gave him his ultrasound has him on a pain medication to comfort him and help his appetite. He is getting plenty of love and hugs and rubs on his tummy with our fingertips to transfer postive energy. We are also trying but not that successful a mixture of cottage cheese and flaxseed oil to help dissolve the cancer cells. We are giving him lamb and rice(dry dog food) and meat for his diet along with omega oil supplements.
What do you think about the K-9 Immunity Critical Care. Please help my Mcleod.
Continue your passion for animals that this world so desperately needs.
Thanks for everything you do for the God’s gifts(animals) who have no voice,
karen in serverna park md
Karen,
I would like to tell you that I know of a cure for cancer that has spread in the body. The truth is I cannot say that and be honest. The best we hope for using supplements, diet, and the rest is improving lifespan and improving life quality. Rarely we get the “cures”.
Will any supplement, including what you mention, cure your dog? The odds are low. You should use some milk thistle (human doses) and SAM-e (human doses). Give with only a little food, and make sure you run this by your vet first. You could also try the homeopathic carcinosinum but you would need to use a vet with homeopathic know-how:
http://www.holisticvetlist.com/
Get the carcinosinum from France, Germany or Holland if you can as they are superior to the ones made in the USA.
Hope this helps,
Dr D
Hi Dr. Dressler,
I have a 16 year old Nova Scotia duck toller that has stage 3 mass cell tumour on his stomach. It was disovered about 6 months ago and we did a biopsy and removed it. It grew back in a few months and ever since we have been just trying to treat the symptoms due to cost and age.
He is currently on benadryl, pepsid, and Prednisone daily. To control his tumour he gets a injection of Kenalog every 2 weeks. This works great for the first week and will almost totally remove the tumour, but after 1 weeks its back again. The vet even tried another type of steriod to see if that would last longer but it didnt work at all and after 1.5 weeks when I took him to the vet he could hardly walk sicne the tumour started to go down his leg.
This kenalog injection works very well, and I am wondering if it is safe to have a weekly injection so he doesnt have to have it get so large the second week.
Look forward to your thoughts.
Ed
Ed, in my opinion weekly injections under most circumstances would be unhealthy. It does depend on the amount used though. You could see if you vet could dilute it down to half strength and perhaps the injections could be given more frequently.
Best,
Dr D
Dr. Dressler
I have a 8.5 year old female yellow lab. She has grade 3 MCTs. The first procedure was done with the vet we used to go to on a regular basis. This vet did a biopsy without doing the needle aspiration first. Once the vet began the biopsy, she found that the mass was attached to the bone and it was beyond her to fully remove. The mass was partially removed for a biopsy. While waiting for the results, the surgery site had become inflamed and eventually infected. I believe that the vet hesitated to recommend a specialist, which elevated the situation.
Once I met with a specialist, I was told that skin around the site had to be removed – it was dead, black skin. This caused an open cavity on my dog’s back leg, with the tumor beneath the open cavity. Amputating the leg was not an option, since the cancer was already affecting her lymph nodes. But, the lymph nodes are not enlarged at this point. We have been working to heal the wound from the outside edges inward. We do bandage changes every day or every other day. Then we had a set back – my dog removed her bandage and got to the wound, upsetting the open site.
At the same time, the MCT on her back leg has been a challenge to control. I have had Georgia on Prednisone from the beginning. We have tried Palladia, but the results were not encouraging and we have discontinued the used of that drug. We have considered other types of chemo, but it is a hard consideration with such an elevated grade of MCTs. We would only be extending her life by a couple of months. She has starting breathing heavily, so we are slowly reducing the Prednisone to eventually take her off the drug.
Now the specialist would like for me to amputate her back leg, because the wound is too difficult to heal. This seems to be the only option that I have. But, I just do not believe that amputation should be a consideration, especially since her time with us is short. The reality is that she may not have enough time on earth to become acclimated to the lifestyle of a 3 legged dog – and then I have put her through more pain than she deserved in her last days.
So my question is this: Is there any suggestions that you have for healing the wound or maintaining the best value of life I can give her while she is with us? Georgia still has a wonderful spirit, making the decision to put her down difficult from my point of view and the specialist’s point of view. We both agree that it is just not time. But I also think she has a personality that will be strong until the last breath. I just want to do what is best for Georgia and her quality of life. Thank you!
Lauren and Georgia Dog
Hi Dr D
My rottweiler Jack who I found dumped in the local streets 2 years ago was diagnosed with MCTs. We immediately put him on a Vinblastine, Chlorambucil and Pred treatment for 4 weeks. Post his 4 week examination the vet discovered that the treatment was not working as his lymph in his groin area grew to the size of a tennis ball. We subsequently stopped the Chemo and put him on Masivet which is a generic of the new wonder drug Palladia.
3 days after administering, Masivet, Jacks condition deteriorated even more and his groin area swelled to twice the size of a tennis ball. His underbelly turned totally red and I rushed him to my local vet. oncologist who indicated that the MCT’s were releasing histamines. I was aware of Benadryl and its properties ( thanks to your blog) and suggested this to my vet, in acting as an anti-histamine. My vet’s suggestion was that he was uncertain as to the reaction of the Benadryl to the Masivet and for that reason did not prescribe it to Jack. 2 days ago Jack went into an anaphylactic shock in ICU and much to my disappointment and heartbreak he passed on. I subsequently have changed vets as I currently have another dog who has MCT’s and who is beng treated with radiation and would hate for the same thing to happen to him.
The question I would like to pose to you ( as a second opinion) is as to whether Benadryl can be prescribed with any other drug and secondly was there anything I could have medically to prevent my adopted son “Jack” from his demise
Regards
Mandi
Hi Dr. Dressler,
What is the general prognosis for a Stage II MCT? I am finding little information on the in-between stages (and early lymph only mets) – just “favorable” for Stage I and “poor” for Stage IV.
We’re going through chemo (vinblastine and prednisone) but I feel like I need to start preparing myself mentally now for the inevitable…
Thanks so much.
Hi Dr. D,
I just found a recurrence of a MCT on my 11.5 y.o. Chessie. We had a rather large tumor taken off his chest about 15 months ago. It was grade 3, and was removed with clean margins – no lymph involvement or mets. This new tumor is about the size of my pinky fingernail and is easily recognizable by it’s granular appearance. I’m keeping an eye on it, and it’s not a high growth tumor, but I can only see the surface, of course. It’s on his shoulder.
I’m no stranger to mast cell problems, as I have Mastocytosis myself – it’s very rare in humans. I have it very well controlled with Pepcid, Doxepin and Ketotifen. (So I’m blocked on H1, H2, and H3)There are less than 20,000 cases of this in people in the US.
I wonder if my Ketotifen would be of any value to my beloved canine kid. Not sure if you are familiar with it, but it’s an H1 blocker, with mast cell mediator properties. Would giving him this with Pepcid be of any help in perhaps keeping the MCT where it is, giving him the chance of a longer life?
I can’t find a canine dosage on it, but my dosage is 4mg BID. There is some info on the internet that it has been used for felines with a dosage of 1mg BID.
I don’t think that at his age that another surgery is an option – he didn’t quite come out of the last one the same dog. It set him back a bit and I don’t want to put him thru it, so we are trying to think out of the box without having a million supplements to contend with.
A bit about him: he’s raw fed by the Billinghurst BARF model – no carbs. Just meat, bone, offal and vegies/fruits. Gets a nice variety of all kinds of meats: sardines, tilapia, beef, chicken, turkey, llama, goat, green tripe, lamb, etc. His treats are all protein: chicken feet, whole sardines, bully sticks, tracheas, ligaments, etc. He was a picky kibble eater, but never turns down a BARF meal. 🙂
Any advice would be appreciated. He’s such a good boy – we’d like to see him have a good quality life as long as possible.
My lab has just received her first treatment of lomustine. I have a golden retreiver in the home too. When my lab goes to the bathroom in the back yard, should I be concerned if my golden sniffs the poop? I also have a cat that goes outside during the day, but comes in the house with the dogs at night. Should I be concerned that the cat could bring an infection back with him that could affect my lab?
Hi Dr. Dressler. Jack had his appt at the U.G.A. vet school yesterday. The result of their staging process was that Jacks cancer had not spread.They recommended removing all the masses and no chemo. The miotic Index was 6.Tonight JACK VOMITED AND HAD DIARRHEA. He never has this problem. I am so worried. Is it possible that it was the anxiety caused by his exam( he was VERY upset afterwords) or the drugs used for sedation?He was very upset today also( the day after).It also stormed today, which really upsets him. Thanks for all of your help.
Hi Dr. Dressler,
My boxer boy has too many MCT’s to remove at this point and I’ve been digging around for alternatives. We have had several removed and tried chemo but unfortunately they just keep coming back. I was just wondering if retinoids are ever used in treating MCT’s? Something like 5-FU or Panretin (topical retinoids used in humans for skin cancer or Kaposi’s sarcoma)? He is getting supplements (Omega 3 fish oil, quercetin, milk thistle etc) and good food but I would still love to be rid of the lumps … somehow!
Thanks for your help,
Mich
My 8 year old lab mix Jack has been diagnosed with a grade 2 mast cell tumor. The vet said this was nothing, twice.The initial lump was there a year and was never larger than a bean. He finally realized it was something when other very small lumps popped up and I had a sobbing fit in his office . He removed 5 lumps all very small. I’m seeing an oncologist ASAP , I just want to ask, is there any hope this has not metastisized?
Kim
indeed, there is hope!
Many grade 2 mast cell tumors have not, and will not metastasize at all. You can get more information about expected behavior by finding out the number of mitotic figures per high power field from the pathologist doing the biopsy report. The vet will know what I mean…
Best,
D