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.
I decided to try some alternative treatments prior to chemo and all that. I started Drew on cimetidine and will be adding fish oil and turmeric. The Turmeric I got is a 400 mg. capsule. How many of those would she need in a day? Thanks.
Laura
Hello
Not sure if you are still giving out advice, but thought I’d give it a shot. I’d appreciate any you have.
My dog Drew is a 9 year old Golden Retriever recently diagnosed with Mast Cell tumor on her elbow. It has grown quite quickly. Measures about 6x6x8 cm (almost baseball size) and it’s in a very difficult spot to do surgery and almost impossible to get clean margins. Skin grafting would be involved and there is the possibility of losing her leg altogether. This is a risk I am not willing to take for a dog her age. The surgeon/oncologist recommended a course of Pred along with Vinblastine to try to reduce the size to make surgery more successful. I brought up the possibility of using Palladia. They have it in stock, but only used it on a few dogs before and believe you get better, quicker and longer lasting results with the Pred/Vin combo. Just wondering what your thoughts were on that. The tumor has not been biopsied so I know nothing of grade or stage.
Can you please tell me how these two treatments compare as far as effectiveness, side effects, length of treatment, cost, etc. I suppose much of this may be individualized to the dog. We went ahead and put her on cimetidine and I will definitely remember about the Benadryl when it comes time for surgery. Thanks so much.
Laura
Wow,thank you, thank you, thank you Dr. D & Blog Guest!
Sammy and I, my black schnauzer/lab/chow mix doggy, just left the vet’s office where she confirmed he has a second MCT. Sammy is almost 10 years old, weighs 65 lbs.(the most he’s ever weighed) and had his first mass removed in May. I don’t know if the vet used Benadryl before the surgery, but I will call tomorrow and ask.
The mass was about the size of a lime, if you slice it in half. However, it seemed to become smaller at times and then large again as quickly as the next day, during the month and a half between diagnosis & surgery, because our vet told me it was not urgent. It was diagnosed Stage 3 Mast Cell cancer when the lab results came back, post surgery.
I immediately started searching the internet for information. I found a lot of positive feedback for Holistic treatment. I started Sammy on an all natural, holistic immunity supplement and we are still transitioning to an all natural holistic diet (Innova), started almost three weeks ago. Sammy seemed to be responding well to the changes and his energy levels are back to pre-discovery of the first lump. His coat and appetite are great.
I discovered the second lump a few days ago under his left armpit, as I was giving him one of those all over body scratch/rubs, that dogs seem to crave all the time, or at least my dog does.(smile) The first lump was on his left side, just below the top of his back, about 3/4 of the way down his back from his shoulders.
The information I’ve learned from this site so far, is far beyond the combined information from our vet and my research on the internet.
At today’s visit, our vet recommended visiting an oncologist and starting the new Palladia drug or surgery. Learning that these are not the only options is a prayer swiftly answered!
Sammy’s quality of life is most important to me!
Thanks Again,
Sammy & TaMara
Hello there,
First of all, thanks so much for this blog.
Second, the back ground. Tabasco is a 6 yr old male boxer. A grade 1 mast cell tumor was located on his testicals sometime in late Feb. or early Mar. On April 17, we completely removed his testicles at which time we got the grading of the tumor. Clean margins with that surgery. A x-ray and ultrasound of his body cavity was also done post surgery when the results came back and he was clear. On May 26, 2009 a second tumor was identified on his left hock and that was removed that day. Came back as grade 2/low MST, dirty margins. I know this is not a great prognosis, but at this point I want to prevent the MST from spreading throughout his body.
The vet recommended applying a bloodroot salve to the excision of the tumor that came back with dirty margins to remove any remaining cancer cells. Do you have any experience with this? What is your opinion? I have found conflicting opinions on the internet. Very positive from pet owners and absolutely horrifying from human use. I’ve seen photos of peoples noses sloughing off.
We did apply it yesterday to the tumor excision site. It seemed to cause pretty severe discomfort for Tabasco so I washed it off about 3 hours before the recommended time. The discomfort lasted even after it was washed off and the site was swollen this morning. I guess that is what you are supposed to see?
Any light you could shed would be greatly appreciated.
Amber & Tabasco
My 10 1/2 year old female Black Lab “Fire” was diagnosed with MCT last October after a lump appeared on her left rear leg. Surgery showed it had spread to the nearest lymph node and both the lymph and the tumor were removed in October. She was immediately placed on prednisone and we have since weaned her to 1/2 a pill every other day. There has been no re-occurrance of the MCT, now seven months post-surgery. Fire also has arthritis, and had responded well to Rimadyl prior to the cancer diagnosis. We had to take her off the Rimadyl due to putting her on the Pred, and we subsequently put her on Tramadol for pain. Her arthritis seems to have gotten worse since the surgery, and we are wondering if it would be wise to stop the prednisone treatment and Tramadol, and put her back on the Rimadyl. Is it possible that her cancer could be in remission after seven months without any signs or symptoms of it’s reoccurring?
Dr Dressler:
My 11 yr old greyhound has been recently diagnosed with squamous cell carcinoma. They are unable to surgically remove it do to the location in her lower jaw. Recommendation is radiation which I will know the schedule today of what they think should be done. What about non-conventional medicine, such as turmeric, and artemisinin can they be used together. Your thoughts would be greatly appreciated.
John
Dear Dr. Dressler –
Our beloved/precious 15 year old Shi-tzu was found to have a tumor on her toe about 3-4 months ago. It then spread to her thigh. It remained fairly quiet when we took her to the vet – they were going to take a biopsy – but she was found to have mild to moderate kidney failure.
About two weeks ago, the area on her leg became very enlarged and red. We took her to the vet and that day they found two tumors on her stomach. They took a biopsy and it was found to be mast cell cancer. She has been eating pretty poorly over the last month – that is when I started supplementing her with “Quick Start” high calorie supplement for dogs.
Two weeks ago – when we got the mast cell cancer diagnosis – I began giving her K-9 immunity power pack. The tumors on her abdomen have enlarged over the past week. We are TRYING”EVERYTHING”……………………………….to HELP HER!!!!!
Do you have any thoughts or recommendations??? THEY WOULD BE ‘profoundly” appreciated!!!!!!!!!!!!!!!!
GOD BLESS YOU!!!!!!!
Diane Krzyzanowski
Dear Dr. Dressler,
My beloved bullmastiff, Lucy, has been living with a diagnosis of multiple grade 2 mast cell tumors since November of 2006. Lucy is now 7 years old.
She has been on Chlorambucil off an on since her diagnosis. The first time she went off of the drug because her lumps had been resolved for approximately 6 months. Sadly, they returned after 3 months and so we started giving her 4 mg of Chlorambucil per day again.
Lucy has twice been taken off of the chemo because, as you can guess, her white blood cell count dropped. She was taken off of the the chemo last August and her white cells rebounded quickly. In the meantime, she was treated as needed with low doses of prednisone (5 mg per day). However, in January the tumors began popping up all over and we put her back on the chemo. Now her white blood cells have dropped again and so, again, we have taken her off of the chemo.
Lucy takes a multi-vitamine, fish oil, vitamin E, Benadryl and Pepcid every day. Is there something more I should be giving her? Is there something I can give her to help her bone marrow?
Lucy’s skin itches her and she has developed very dark patches on her belly where her legs and tummy rub together. She licks it all the time. I have a topical treatment but it doesn’t really do much.
Lucy is 94 lbs and that is actually big for her frame. Even though she is a bullmastiff, she is a small one. Her appetite is great. But her tummy has always been sensitive – since she was a puppy. I have heard that virgin coconut oil may be good for her skin. Is this true? If so, what should I get and how should it be administered?
Please let me know if there is something I should try for her bone marrow and/or her skin. I will do anything for her.
Thank you very much for your time.
Sincerely,
Catherine
Hi Dr. Dressler,
I have an 11 year old Weimaraner that started getting MCT’s when she was 2. Every other year, she has to go in to get two or three removed at a time. In the past, I’ll notice the larger one (usually about the size of a dime) and my vet will find one or two tiny ones during the examination. Her last surgery was in 2007 to remove 3.
This time around, I noticed a large lump pop up on her right rear leg in January. Then a tiny one appeared on the top of her head and another small one on her front right leg. The difference this time is she has been obsessed with licking the one on her rear leg to the point where the skin on top is rubbed raw and it bleeds. She recently started licking the one on her front leg and it started bleeding too.
I took her in for her annual visit and my vet seems to think they are all MCT’s, based on what they look like and her history. He’s very concerned with the one on her back leg due to it’s location, size, and the ability to get enough margins around it.
I need someone to be very frank with me and tell me what can happen to her. Money is very tight right now and I don’t have extra cash. I will do everything in my power to get them removed, but I don’t know how much time I have considering her age, their size, her licking them, etc. Have you ever heard of a dog licking them like that? Thanks for your great site and information.
Hi Dr Dressler-
I’ve recently discovered what appears to be two dark skin tags, one on the back left leg and one on the back, and a small lump slightly larger than a pea near the ribs of my seven year old pug Iggy. My boyfriend and I have just moved to a small town and have enjoyed our new veterinarian. His bedside manner is comforting, he seems knowledgeable, and the staff is very sweet. Today we took Iggy in to look at the skin tags and lump and decided to schedule surgical removal and biopsy of these growths.
I myself am a nurse and wanted to be prepared to discuss all possible options with the vet and had read about MCTs and corresponding treatments before our appointment. I voiced concern about possible MCTs and followed up with asking about the anesthesia he uses for surgery. He detailed pre-medicating with Ketamine and I believe Fentanyl with Isoflurane during op.
I mentioned the Ketamine/ metastasis connection and also pre-medicating with benadryl due to possible histamine release. Both suggestions were basically pooh-poohed as something he’d never heard of (the ketamine) and that the growths were too small to release sufficient histamine for benadryl to be needed. Now I’m afraid he thinks I’m an internet junkie who can’t seek out reputable information… I realize that Iggy hasn’t been diagnosed with mast cell tumors YET but pugs are susceptible and I want to take all precautions.
I have two quick questions.
1) Would it be safe to give Iggy OTC benadyl the night before surgery if Dr won’t give IV? He’s 17 lbs and the dosage suggestion I’ve found would be 10mg po.
2)How hard should I push the ketamine issue? Should I go to another vet?
I’m also including one of the few articles I could find regarding Ketamine and Metastasis from Anesthesia and Analgesia. Hope this is helpful to others out there with skeptical vets!
Thanks again,
Andrea