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.
it can spread to the other organs ,,according to my vet
Janet
Hi Dr. Dressler,
Thanks for a great site! My 8 1/2 year old lab had a Grade 2 MCT removed last year (under front leg), now she is coughing which the vet has treated a potential low grade pneumonia, however after 4 weeks it is not responding, it is getting worse if anything. My question would be and i understand you can’t give specific advice so will try and keep this generic:
Do MCT often spread to the lungs/chest? (lymph nodes in chest), if it has spread to the chest i’m worried her end will be particularly unpleasant (choking), is this likely with a MCT on the chest? What is the best way to appraoch MCT if it is the chest in your opinion?
many thanks for your help. Please keep up the good work!
Hi Dr. Dressler:
I was wondering if you could please address my question on bloodroot.
Thanks so much.
Joanne & Cassie
Hi Dr. Dressler,
Thank you for this wonderful site.
I have a 7 year old yellow lab who just had surgery for a stage 2 mast cell tumor. My vet said the margins were clear.
She has not recommended any further treatment. I have been researching and switched his food to Eagle Pack Salmon Dry Food and grain free Wellness canned food.
DO you think this food is a good choice for him?
Also he has never shown any signs of allergies at all, should I consider giving him benadryl anyway? I have read so many reports that this helps the Mast cell tumors. Unfortunately I found your site too late to give him benadryl before his surgery.
Also I have researched the Professional Vet Immunity Tablets and K-9 Immunity do you feel this would be beneficial to him??
Should I give him additional fish oil tablets??
Thank you for any advice you can give me. I feel there should be something else I should be doing instead of just the surgery!
Thank you so much!
Barbara
Hi Dr. Dressler,
My husband and I adopted an 8yo husky/shepherd mix named Ike with a grade 2 mast cell tumor. He was being euthanized on a Monday morning and we took him in the previous day to try and give him the best life possible. He is truly amazing. He is going to have surgery to removed the lymph node as the tumor is no longer there (he chewed it off) and chemo will be given after he heals. I want to do everything possible for him and I feel very confident with both my vet and the surgeon. I do however feel I’ve been lacking knowledge in the area of diet. I’ve read some of the entries from above, but would please recommed a food, etc…? He is taking benadryl, pepcid, prednisone along with sucralfate daily and want to provide the best diet with interfering with his medications. Any information would be very appreciated and thank you for this wonderful blog.
Lori
Some options are Innova Evo, ND food by Hills, Blue Buffalo.
Change foods slowly by mixing over 7 days or more!!!
I will discuss diet is the upcoming webinar, and will go over your question in more detail:
http://dogcancervet.com
Best,
D
Oh yes and Wysong now makes a cancer diet that seems good,
D
Dr D,
I have an 11 year old rat terrier that had a stage II mast cell tumor removed from his chest mid Oct. Our vet thought he got it all at that time but just over a month later another appeared in the same area (this one a little to the right and into his front right axillary area). Within just a couple weeks this tumor grew to about the size of a lemon. We decided to take him to an oncologist for tx options. She said they could not surgically remove the tumor due to the location (looking at amputation) and the extensive surgery he had for the previous tumor and no radiation due to possible damage to lungs. We decided to go with Vinblastine tx’s (also on dexamethasone, benadryl, pepcid, tramadol). After his 1st tx we started noticing the tumor shrinking and were hopeful we had bought some time with him. He had his 2nd tx Mon. so I was really thinking I’d see good results, well now it is Thurs and not only does it appear bigger but he also seems more uncomfortable. I guess my question is….is there anything we can do that we are not doing to help him or is it too late and he only has days left? I have not noticed any systemic signs of the cancer. His appetite is great, no vomiting or diarrhea. He walks with a limp and has been grunting a lot today and just seems like he can’t get comforable. Any advice or insight would be greatly appreciated.
Sincerely,
Emily
Dear Emily,
you may be able to have your vet enroll your dog in the compassionate use program for masitinib through Dr. Ahn, who is president of AB Sciences. The company is located in New Jersey. Masitinib is a chemo drug that is used in Europe for mast cell tumors but does not yet have FDA approval in the USA. It would be a good option to consider.
Best,
Dr D
Hi again Doreen:
Forgot to tell you that I also give Cassie Tumeric (Curcumin) mixed with Letchithin every day on her foot.
Joanne
Hi Doreen:
My seven year old border collie was diagnosed with a mast cell tumour on her right hock. She has gone through many weeks of chemo and the tumour has completely disappeared. She is in total remission.
The diet that I give Cassie is one where there is not wheat products in the food. It is called Holistic Blend. Do not know if you can get it in the States. I also give her flaxseed powder and coconut oil along with K-9 Immunity and K-9 Transer Factor. She also gets four fish oil caps every day. She too is on Prednisone but the dosage has been cut down to a 1/4 pill per day. I am now checking into Bloodroot – it seems kind of toxic and am not sure if it is a good thing. We will have to see what Dr. Dresslers’ comments are on this. I wish you all of the best. The chemo seems to be the best thing. We had Pet Insurance so it cost us about $2,900.00 out of our own pocket and the insurance paid $2,000.00. I would imagine in the states you have better coverage for animals than we do here in Canada.
Good Luck and I hope that this helped.
Joanne and Cassie(my baby dog)
Dr. Dressler,
I am curious whether you have heard of treating mast cell tumors w/ a drug called “masitinib” which is a KIT receptor inhibitor?
http://www.ncbi.nlm.nih.gov/pubmed/18823406
Hi Jonathan,
yes, a drug that blocks a mutated Kit tyrosine kinase receptor found on some mast cell tumors. It is not available yet to my knowledge:
“The Committee’s conclusions by majority decision at the end of the re-examination procedure were
that the benefit-risk for Masivet was considered acceptable in a restricted indication for dogs in a sub-
group that exhibit a positive response to treatment (i.e. treatment of non-resectable dog mast cell
tumours (Grade 2 or 3) with confirmed mutated Kit tyrosine kinase receptor) and, therefore,
recommended the granting of a marketing authorisation for Masivet. ”
Not for all cases of Grade 2 or 3 MCT!
I will talk more about this pending drug in the webinar…see:
http://dogcancervet.com
D
oops, started this but mailed it by mistake.
My female english setter, Chloe, is near 12 years old. She was diagnosed with hemangiosarcoma 15 months ago.. Her spleen was removed and weighed 5.5 pounds. Now they don’t think she was misdiagnosed because she lived so long without treatment.
Today, April 13th, she has been diagnosed with a mast cell tumor via biopsy.. It is on her right had lower leg, near her foot.. Too tight to excise because they can’t get good margins. The lymph node in same leg,in her thigh, is involved. She was given 50 units of ccnu 2 weeks ago and is still on prednisone, benadryl and pepcid. I followed up with an ultrsound today to see what else might be involved. It has spread to an inch tumor in her spine near her bowel. I have been feeding her EN formula dog food since her hemangiosarcoma diagnosis 15 months ago, afraid to feed her off the shelf dog food. It is supposed to be easy on the stomach but has rice in it.. Now, I read that grain is not good for dogs and might trigger mast cell tumors. Not sure what to believe and what to do at this point. Anybody out there with any advice?
Doreen,
grains are not pure evil in dogs with cancer. Carbohydrates should be restricted though. Go for a food like Hills ND, Blue Buffalo, Innova Evo, and Wysong makes a new cancer diet I have heard is good. Go for, on a dry matter basis, about equal parts protein and fat and about 2/3 of these carbohydrates..very roughly. There are recipes in the book available above…
D
Doreen I will also answer more detailed questions this Sunday on the webinar if you are interested:
http://dogcancervet.com
My female english setter is near 12 y