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

Mast Cell Tumor Surgery and Benadryl

Updated: December 12th, 2018

The mast cell tumor is very common in the Pug, Boxer, Rhodesian Ridgeback, Shar-Pei and other breeds.  This tumor most commonly occurs in the skin as a raised, inflamed nodule or mass. Sometimes it is found internally in the liver or spleen.

The cells that make up this tumor are called mast cells.  There are some unusual aspects of these cells that should be paid attention to.

First, they secrete a substance called histamine, which most have heard of in the word “antihistamine”. Histamine is released in the body during allergic reactions and it causes some nasty things. First, histamine causes inflammation, which is no fun for anyone. Redness, swelling, pain… all parts of inflammation.  If you squeeze a mast cell tumor, many will create a red, swollen effect due to the histamine that gets liberated.

Histamine can cause serious harm to the body when released in larger amounts.  When a dog experiences massive histamine liberation, her blood pressure can drop through the floor, causing life-threatening shock.  No blood pressure, no blood getting to vitals like the brain and kidneys.  Bad news.

Imagine if you were to do surgery on a mast cell tumor loaded with histamine.  This is more than just squeezing it, folks. We are talking scalpel action, along with some pulling to free up the mast cell tumor. Imagine the amount of histamine that could be released.

So, it is wise to make sure your vet is on the ball.   Since doing surgery on some mast cell tumors can result in shock, make sure you double check that your dog gets an injection of Benadryl before surgery.  This can block the effects of massive histamine release. Also allow your vet to place an IV catheter and deliver IV fluids or meds during the procedure to keep the pressure up.

Dog cancers are all different.  Each tumor in dogs behaves differently and needs it’s own special treatment.

Stay tuned!


Best to all,

Dr Dressler


Discover the Full Spectrum Approach to Dog Cancer

Leave a Comment

  1. Susan Kazara Harper on June 23, 2015 at 8:06 pm

    Tanya, This reply is late, but you will get no bashing here. What did the vet day?

  2. Tanya McCollum on May 28, 2015 at 6:04 pm

    I have an American Bulldog. She had a tumor removed from her chest about a month ago. The incision healed up perfect. The vet said the majority of the tumor was benign but it did have a little bit of cancer cells in it. She said that it was grade 1 . Anyway she has started developing blood blisters on her back side and on her belly and by her front left leg( like what would be her arm pit) . They are bleeding constantly and not clotting. She is dripping blood everywhere. I have tried to bandage them up. I am calling the vet tomorrow, I was just wondering if anyone had any thoughts on this. Please don’t bash me. I am calling the vet. I love my dog very much. She is 8 years old and about 105 lbs. She doesn’t chew on her blisters or anything they just keep bleeding. All the hair has come off and they look really sore but she does let me touch them to try to bandage them. Thanks

  3. Susan Kazara Harper on December 7, 2014 at 10:49 am

    It’s scary and a big responsibility, but you are your dog’s champion. Trust that you will know what he wants and that whatever you decide will be the most loving thing you can do to help him. Every dog is different. While you have him, focus on the joy of each day together. Check out https://www.dogcancerblog.com/full-spectrum-cancer-care/how-to-know-if-your-dog-is-in-pain/ and work with your vet. Give him the best, real foods you can, and know that some days he may want to be fed by hand, which is such a loving thing to do anyway. He will tell you each day how he is. Dont’ stop play, which is his joy, but you may need to modify it. Roll the ball to him instead of making him chase it. It’s all good. Check out https://www.dogcancerblog.com/?s=play
    All the best to you both Chris.

  4. chris on November 24, 2014 at 12:39 pm

    I was wondering my dog has the same symptoms as your dog,and they also told me 4 to 8 weeks,, what should I expect toward the end or when I have to put him to sleep … im scared of losing him thanks

  5. Susan Kazara Harper on September 8, 2014 at 1:31 pm

    Hi Debra,
    I’m sorry about your girl’s diagnosis, but you stay strong, OK? It’s great that you’re seeing an oncologist. If she is itching, then an antihistamine like Benadryl could be a good idea, but 1) consult with your own vet about this, and 2) don’t just give her an antihistamine if she’s not having itchy symptoms. When you see the oncologist you want to get the grade and stage of the MCT, as that information will go a long way to helping you decide on treatment. If your girl does get itchy, take a look at https://www.dogcancerblog.com/blog/food-and-nutrition-for-dogs-with-mast-cell-tumors/ …. it’s a blog which works on top of the Dog Cancer Diet to further restrict foods which may make itching worse. But again, don’t go there unless she needs the extra help. No need to make things more difficult. The Dog Cancer Survival Guide has a great chapter on MCT; well worth reading, especially if you can get it before your appointment. Don’t hesitate to get in touch if we can help in any other way. We will all keep fingers and toes crossed for a good appointment. Stay strong, stay happy with your girl, because that’s what she’s concerned about every day.

  6. Debra Armbruster-sells on September 8, 2014 at 6:32 am

    Dr. D my 7 yr old boston terrier has had 2 surgeries to remove tumors the last groin mass path was lymph node mast cell tumor. We are seeing an oncologist next week and I’m very concerned since she now has multiple skin lesions, cysts around her anus and a lump adjacent to her surgical scar. Should I be giving her benedryl until she’s seen it seems these tumors are growing fast she weighs 28 lbs. she is my baby and I will do all I can to help her. Deb

  7. Tatiana on August 18, 2014 at 8:33 pm

    Hi Dr Dressler! I’m writing to you because I’m so afraid!! My dear 14 years female Pittbul almost one year ago was affected by Dermodex and since this time, over her ear flap she has a small tumor that on the beginner the vet that has accompanied her thought that was only a simple abscess without any malignancy. After we ask so much, one month ago he made a valuation of the abscess and so we had the knowledge that she has a mast cell tumor. I need to decide what to do!! Should I removed all ear or only the tumor at first moment to evaluate what is the grade??? She also had breast cancer three years ago and we did total mastectomy. If you can help me I’ll be so grateful! I love her so much and I want to do the best to her! Since now thanks!

    • Susan Kazara Harper on August 20, 2014 at 12:52 pm

      Hello Tatiana,
      Not Dr. Dressler here, but I hope I can help.
      It’s important to get very clean margins with MCT (well, with any cancer too). and the ear is often a pretty good place to be able to do this. Depending upon the location, your vet may be able to get enough tissue to really take that MCT, and if there has been no spread (metastasis) in other parts ofthe body it’s even better news. Might your dog lose a good part of the ear, or even all the ear? Well, possibly. But she’s got two 🙂 and I promise she won’t be bothered at all if she looks a little lop-sided. She’ll just be happy to feel good! We humans get kind of queasy with taking off body parts. Dogs don’t mind at all. If you have a smaller surgery to determine the grade, you will very likely be looking at a second surgery to have the entire MCT removed… double surgery, double sedation, double expense. You can talk this through with your vet and weigh the pros and cons. One thing for certain, if a cancer can be cut out completely there is a much better chance of winning the fight.
      Please don’t focus on fear. It does nothing to help either you or your dog. Instead, channel that energy into determination to get through this! Good luck, and give that girl a big hug from all of us on the team.

  8. Susan Kazara Harper on August 7, 2014 at 11:52 am

    Sorry to hear about your Rottweiler, and I’m glad you have an oncologist to work with. They really are the experts in veterinary cancer. It wouldn’t be appropriate to try to offer treatment options for your boy, but if you feel that the protocol offered needs to be questioned, by all means question it. Has your oncologist told you why he or she doesn’t want to use Preds with Masivet? There will be a reason. If that reason doesn’t satisfy you, please do ask to get a second opinion. It’s within your rights, and no one knows your dog better than you do. Ultimately, his treatment is your decision.So, take your questions and any data you have found to your oncologist, or request an appt to go over these details. You need to feel, in your heart, that the steps you take now for your dog are the best ones to take. Please make sure your boy is on the best nutrition. You can download the Dog Cancer Diet (www.dogcancerdiet.com) and further modify that with the blog we wrote on nutrition for dogs with MCT https://www.dogcancerblog.com/blog/food-and-nutrition-for-dogs-with-mast-cell-tumors/ Give your boy a big, rotty cuddle from all of us, and good luck.

  9. Angela Hemingway- Leigh on August 4, 2014 at 12:52 pm

    Hi my Rottweiler aged 3 has had mast cell tumor grade 2 removed from hind leg – it has spread to lymp nodes , he has been prescribed masivet but my oncologist said no to prednisone , I thought to give my dog the best chance of survival it should be taken together ? Can you please help

  10. Dawn on November 18, 2013 at 1:29 am

    Hi my dog Jack is a 10 year old boxer, and has what I am sure is a tumor in his nose it has been I believe a little over a month and it started small about a marble when I first noticed it and now about the size of a kiwi he is rubbing it and then bleeds some and some clearish yellowish ooze not alot but I dab it off and put neosporin on it. I also heard that tumric is an anti flamitory, so I have been making rice with it and giving him that I want badly to take him to the vet but I can’t afford even just the visit right now. I just went through breast cancer with my girl boxer that lost her battle 3 yrs ago. Would or can I give him anything like benadryl or anything. I havebeen looking for help but most all say they need a vet to verify, I am going to try some fund raising. I am just miserable watching him and this thing take over his face and now very close to his eye very close, I know he hates it and can’t imagine what he is really going through.

    • lisa on July 24, 2015 at 3:09 am

      my vet told me to give Benadryl. I also read to switch them to a grain free healthy diet and I am now going to start giving Raspex. Read about it, there is a lot of info out there. hopefully all the above will avoid surgery

  11. bee1 on August 30, 2013 at 3:56 am

    My dog, a 10 year old, 64 pound male boxer, is scheduled for surgery next Thursday to remove a mast cell tumor on his side. Over the phone yesterday, I heard my vet recommend 75 mg of Benadryl 3x a day prior to the surgery. Based on the the human dosage on the box of Benadryl, this seems like too much, but perhaps is correct based upon the circumstances. My vet is out of town, her assistant is not in the office today, the pharmacist at the vet gave a confusing answer, as I am sure the message delivered did not contain all the relevant details and I have left a message for another vet to confirm, but haven’t heard back. Would this dosage seem reasonable for a 64 pound dog, prior to surgery?

  12. janie on May 23, 2013 at 12:07 pm

    We have a beautiful 6 year old rescue goldendoodle-we discovered a MCT on his back paw which was removed in surgery and was malignant. However, because of where it was, no clean margins. No spread/nothing in lymph nodes or anywhere else in body. Our pup has an extremely sensitive stomach and tends to get very nervous easily. He didn’t do well under anesthesia when the tumor was removed. After visiting with the oncologist, we have decided to do another surgery to remove the part of the paw where the tumor was….the thought of doing 18-20 radiation sessions with him is frightening. Any thoughts on this course? the oncologist thinks we have a 90% (Yes, he said it) chance to getting the margins. thank you.

  13. denise on September 22, 2012 at 4:11 am


  14. Michelle - New Zealand on August 27, 2012 at 4:57 pm

    Hi – my 15 year old standard schnauzer Millie had a growth removed (clear margins) from her perinium which was diagnosed as a Grade 3 mast cell tumour. We started her on chemo (Vinblastine) but have since found it it was wrongly diagnosed and now 2 NEW pathologists have described it as a low level neoplasm AND as a Grade 2. Does this mean this is a low level Grade 2?? – the vets here in NZ are not giving me much info including the specialist we are seeing. We are still doing the chemo but had previously (when we thought it was a Grade 3) intended to use Palladia after the chemo. An ultrasound has shown no spread anywhere else. Do you think we need to put her on Palladia as well. I don’t care about the cost but worry about the Palladia side effects – but of course I don’t want to take any risks that the cancer will come back/spread. She is very fit and healthy and has had no side effects after increased doses of Vinblastine each time. I really would like to know what a “low level neoplasm, Grade 2” means. Thanks for any advice you can give me, it would be very much appreciated. I have been googling but am going around in circles.

  15. Jennifer on August 20, 2012 at 2:57 pm

    My boxer had a Grade II MCT removed from her back two weeks ago. They had to cut some muscle to get to it. The doctor wasn’t able to entirely get clean margins. Two days after surgery the location swelled to the size of an orange. Took her back to the vet who prescribed anti inflammatory meds for four days. One week after, the incision broke open and oodles of blood poured out and the orange went down to an egg immediately. Took her back to the vet and he put in staples, told me to use warm compresses twice daily and put her on Benadryl. Today two weeks later, the swelling is a little less every day, but a pretty hard rectangular feeling lump (muscle??). I am not getting any answers from my vet. She has a great appetite, active, etc. Help.

  16. kimk on August 2, 2012 at 1:37 pm

    My dog had a large 1-2 centimeters on his back left paw. The vet removed it and took one of the toes. Came back as Grade 2 , the margins are not clean but they were tested and the grade was 0 as far as reproducing (i think), they removed the sutures and aspirated the lymph node behind the knee, it has spread. My vet says to remove the lymph node, and try to clean up the margins if possible and start chemo. Right now he takes 2 1/2 tables (20 mg pills) each day. I love this dog so much, anything that you can reccommend?

    • Dr. Susan Ettinger on August 10, 2012 at 10:09 am

      Based on what you have told me, for the paw area and the node, the options are surgery or radiation. The paw area can be challenging to get clean margins because there just isn’t much tisse there to remove. And then I would follow with chemo. Good luck!
      All my best, Dr Sue

  17. Dr. Demian Dressler on July 10, 2012 at 10:03 pm

    Second Dr. Sue…
    Dr D

  18. joanie on July 3, 2012 at 1:24 pm

    DR D, My 7 yr old Boxer has been diagnoised with MCT ,she was scheduled for surgery this morning , I found one more spot on her leg .the first was found in the chest and he did a needle aspiration and it was positive in both sites . after dropping her off ,the vet called me and said bloodwork was great , but since she had 2 places now that it is spreading and he did not think surgery would help and actually make it spread worse by opening the sites , .do you think i need to get a second opinion ? please help me .

    • Dr. Susan Ettinger on July 7, 2012 at 8:00 am

      Yes, I think a second opinion is never wrong. You need to clarify whether the tumor has spread, for example to a lymph node, or are there multiple MCT in the skin? This is not considered a spread but multiple primaries. While MCT are treatable, it is not a one-size-fits-all treatment plan. So seek out a medical oncologist, get more info and get specific recommendations for your dog’s situation. Then you can make a good decision!
      You can check out http://www.acvim.org to find a specialist by you.
      Good luck!
      Dr Sue

  19. joanie on July 3, 2012 at 1:03 pm

    Hi cassandra ,The Boxer you found still has about 4-5 yrs left .. sometimes the tumors are just fatty .. if you feel you cannot keep him please call your local Boxer rescue ,please do not take him to a Shelter they will put him to sleep .please see if you can find any rescue locally to help you .. good luck ..i have 3 Boxers and they are lovers ..

  20. cassandra on May 29, 2012 at 12:09 pm

    i found a 9 year old boxer he is very old and loves to sleep and has 3 tumors , i want to keep him but my mom said it would to much money for us. if he is that old would it be worth giving it a try with the vet to get him healthy agian ?

  21. chris talty on May 15, 2012 at 1:07 am

    our dog has a 2cm mast cell tumor near her sternum. we don’t have access to any testing facilities, so surgery is the only option. she is 12.5 yrs old, has a history of nuerological problems, immune difficiency(demedex), & liver problems. considering the risks & discomfort to her associated with surgical removal, & the uncertainty of the stage of the tumor, given her age & history, how does the risk of this procedure compare to the probable benefits to her in terms of comfort, quality & longevity of life.

    • Dr. Demian Dressler on May 18, 2012 at 9:39 am

      Dear Chris,
      you really need to speak with the surgeon on this one. I am sorry but I would need many more specifics and also hands on the dog to make a call as all cancers and different in given dogs. Having said that, I have no hesitation about removing tumors surgically in dogs of this age, but again, you need to talk with the one doing the surgery…sorry.
      Dr D

  22. Fran Rosenthal on May 9, 2012 at 8:35 pm

    My 15 year old golden retriever/lab has a small mast cell tumor on the underside of her ear flap. It was diagnosed as a “well differentiated mast cell tumor” but was not given a “stage.” Should I have her ear flap removed at 15? My vet suggested to first do an ultrasound to see if she has any tumors anywhere else. I’m starting by putting her on Benedryl.

    • Dr. Demian Dressler on May 18, 2012 at 9:53 am

      Dear Fran,
      you should have a consult with an oncologist, or perhaps your vet should for clarification on the path report. Many pathology services that are used have consultations free of charge. Most of the time we remove mast cell tumors in dogs with wide margins. I feel the recommendation for the metastasis check is good (including also chest X-rays with blood and urine testing along with the ultrasound) as your first step. After that, you need to decide what your treatment priorities are for your dog:
      I hope this helps
      Dr D

  23. Barb dodge on August 24, 2011 at 2:03 pm

    Howdy Dr. D,
    My 6 yr old lab recently had a stage 1 mct removed w/ clear margins. Being stage1, should he be taking Apocaps and starting the cancer diet?
    Can you tell me how you incorporate Halo dry into the diet- do you use Halo then add the veggies,oatmeal,calcium,fish oil and any of the optionals- or do you cook the meat, liver too and add Halo along w/ the above items. I guess my question is does Halo replace the meat and liver ? Also, can you give me ballpark serving size for a 75 lb lab? One more question, should this diet be served to non cancer dog?

    • DemianDressler on August 24, 2011 at 6:54 pm

      Dear Barb,
      the main question is whether this was a wide excision or not. Clear margins do not give us that much info if the excision was not wide. If it was, almost all the grade 1 MCT will not recur (are cured). The Halo food replaces the entire recipe, not just the meat. if you are doing half cancer diet and half Halo, use half of what the bag indicates. Halo is fine for dogs without cancer, but the cancer diet is for dogs with cancer only. Apocaps are fine (under veterinary supervision). I would use half the labeled dose if this tumor was removed with a wide excision.
      Dr D

  24. Charlie on August 18, 2011 at 2:43 pm

    My 12 year old Toy poodle/Bichon has a mast tumor in the area of the anal gland .The vet found it while my dog was getting expressed for the first time by a vet. He said hes not positive if it’s the one that spreads..and recommended i go to this other hospital..My dog did have i think a small seizure when he was sorta twitching and his hands shaking and trying to walk all at the same thing type of motion. It scared me but my mother massaged him and he’s better. He’s okay now. But Is this surgery worth doing? Will his bowels be damaged during this surgery making him to use the bathroom everywhere and uncomfortable ? I don’t want him to suffer however i dont want to lose my buddy that i love..What should i do? Is this surgery successful what are the odds ? Someone help me decide on what to do I’m very confused….thanks.

  25. arislargy on August 7, 2011 at 10:52 pm

    surgery insulin plan b-low motion

  26. Steve on May 14, 2011 at 8:46 am

    Dear Dr D

    Thank you so much for yoru website and blog. I will be purchasing your ebook.

    Wanted your advice or any thoughts on our situation.

    Our 5 year old golden retriever was diagnosed with mast cell cancer– stage 2. The cancerous growth is on his upper lip and is quite large– extending to his nose. The dr’s that looked at him said the the risk/reward case was not there to do a surgery because of the location and the possibilty that his nose would have to be removed, as they have to cut 2-3cm each way. Pretty much said that chemo or radation will be pallivtive– just by some time. The mast cell is also infecting his local lymph node. So no surgery is possible.

    I can tell that our dog is uncomfortable– still eating but only a little and still walking although he sleeps most of the day and is going for shorter walks.

    I was not given a time of how long he will live, as I just got the results on Friday.
    The reading I have done so far on oral cancerous growths is not too positive. I dont think that we will do chemo/radioation therapy– even the surgeon that was telling us didnt sound too enthusatic about it.

    I have seen some supposed natural products for sale online– any thoughts on any of these? is there anything that we can give him to make him more comfortable? Any drugs that are specfic to this type of treatement?
    What is your experience with oral cancerous growths– mast cells etc..

    Currently we are just giving him benaydryl as that was recomonded to keep the swelling down. Im not looking for a miracle cure but the only other thing that was said by the vet is to possible try presdone(not sure of spelling) but the side effects do seem harsh.

  27. Gloria on May 13, 2011 at 5:30 am

    Dear Dr. D,

    My 14-year old English cocker had two histiocytic/epithelial growths removed two weeks ago. The dermatologist recommends lomustine once a month for four months to slow the reoccurence of these. How long do the incisions need to heal before beginning the lomustine regimen?

  28. Helen on May 8, 2011 at 1:45 pm

    Hi my 13 year old jack russell has a grade 2 mast cell tumor on her lower bellie. she is currently on predisone which has helped a little, my question is she is a very difficult patient evan a general check up at vet requires her to be placed in a gas box so as to knock her out as no one can touch her. I am at my wits end as i love her equally as my own children. I dont no if surgery to remove the tumor will be to stressful for her and how she will cope after ,my vet would put dissoluble stiches. i’d appreciate any info thankyou

    • DemianDressler on May 18, 2011 at 9:32 pm

      Dear Helen
      sorry to hear about your little one.
      One of the problems with these tumors is that some can be very dangerous, even life threatening. If this were my dog, I would consider the surgery. Discuss with your vet. If your little girl was my patient, we would consider Kinavet, diet change, apoptogens, and the other steps you can take in the Guide, under veterinary supervision. Last resort is Neoplasene.
      Dr D

  29. Patricia on March 12, 2011 at 11:55 am

    Dear Dr. D-

    I am pretty glad I found your site today! My 18-month-old boxer puppy Becky is having a suspected mast cell tumor removed from her left “elbow” Monday morning. I was reading up on you recommendation to administer Benadryl prior to surgery and will certainly ask my vet to do so…it certainly can’t hurt!

    I am concerned about them being able to get clean margins when they excise the tumor given that its in a rather boney, non-fleshy area. She just successfully completed a lengthy regimen of prednisone and antiobiotics for boxer acne and we noticed the suspected tumor at that visit. While the boxer acne vanished with the medication, the suspected tumor has more than quadrupled in size over the last month. I am concerned about the implications of such rapid growth in such a young dog. Does this bode poorly for her to make a full recovery?

  30. Joanna on February 28, 2011 at 12:45 pm

    Dear Dr D,
    I’m writing to your from Poland.
    My 7-year-old American Staffordshire Terrier female –Asia was diagnosed with Mast Cell Tumor a year ago. She had two tumors completely removed – a coetaneous one on her back and a subcutaneous one on her left thigh. The tumors were diagnosed as low grade II, stage I. From March to December 2010 she was on prednisone. Two oncologists – one from Poland and one from Holland have been taking care of her.

    All her blood, urine tests, ultrasounds etc. have been ok and she’s had them done every month since March 2010.

    In August 2011 I spotted another subcutaneous tumor on her right rear leg “ankle”. Although at that time she had been on prednisone for almost 8 months, the tumor got smaller and bigger every now and then. In January’11 her Polish vet performed a fine needle biopsy of that “ankle tumor” and it turned out to be MCT grade II again. Then I took Asia to Holland for further exams. Again Asia’s had all the blood, urine tests done, lymph nodes checked, ultrasounds etc. and all is fine. Since the tumor is subcutaneous and is on Asia’s ankle her vet from Holland is very much against surgical removal of that tumor, so also no other exam like histopathology is possible to assess further characteristics of that tumor ( stage, mutated C-kit receptors etc.) .

    Since it’s impossible to exactly assess the tumor – if it’s low grade II or bad grade II ( although the vet from Holland says that it seems to be a low grade II – considering Asia’s history, good results of blood, urine tests etc. and the fact that the tumor has been on her “ankle” for some time and did not metastasized) the vet from Holland has put Asia on Masivet and decided to treat the tumor as a marker. After 3-4 weeks we should know if Masivet works or not. If it doesn’t, we will only know that the tumor doesn’t have a mutated C-kit receptor but we will still not know if it is a low-grade II or bad grade II tumor.

    If Masivet doesn’t work, the vet suggests considering radiotherapy – but it doesn’t work on low grade tumors:(. So, if this tumor is a low-grade II, radiotherapy is useless here. So….I’m confused and don’t know what to do next. How can we get rid of this tumor? Is it possible without surgery in your opinion? Do you think electrochemotherapy could be a solution here?

    I’d really appreciate your help as here in Poland we don’t have educated vets, let alone oncologists ( my local vet-oncologist can’t help me as we don’t have radiotherapy for animals in Poland and Masivet is not used here either)

    Kind regards

    • DemianDressler on March 8, 2011 at 10:12 pm

      Dear Joanna,
      I am not sure why the recommendation against surgery was made. Maybe they are worried about delayed healing due to tension on the surgery site? Also, I am not sure how a fine needle aspirate yielded a grade, since that is done with a biopsy. I would not treat this as low grade just because there are no signs of spread (yet). My feeling is to get this thing off and if needed, immobilize the joint with a splint if needed to allow healing.
      I hope this helps,
      Dr D

  31. Sarah Berry on February 22, 2011 at 5:24 pm

    Hi Dr. D –

    My 7 year old Boxer just had surgery on his mast cell tumors today. He had five of them removed. Upon getting him home, I found another, potentially two more that neither myself nor the vet had discovered prior to his operation. Is this of huge concern?

    I’m feeling like putting him through the surgery and paying all that money to get those tumors removed was a waste, because not all of them were taken off. Does removing the majority of them help, or do all of them need to be removed for him to successfully recover? I really hope I didn’t put him through all of this for nothing. 🙁

    • DemianDressler on March 8, 2011 at 10:23 pm

      Dear Sarah,
      this is tough. You might want to consider an oncologist consult, Apocaps (you should read the reviews on Amazon), dog cancer diet, benadryl, and an antacid, as minimum action steps. Consider Neoplasene topical as a last ditch choice too…
      I hope this helps
      Dr D

  32. david on February 16, 2011 at 11:54 am

    our dog has had lumps for 2 or more years…first few vets diagnosed as tick bites.
    the needle aspirates came back as MCT.
    we saw an oncologist, and a board certified surgeon. He had surgery, and we ust got the biopsy results back this minute shane had 7 tumors removed and they missed one(ut its small)
    but the tumors were grade 3 of course. he is only 7 and this sucks. grade 3 cancer idk what to do.
    when we met the oncologist he told us that palladia has bad side effects in 25 percent of the patients….my dog is gonna die in a few mnths, and we put him through surgery for nothing. he had a tumor on his paw removed and now is limping…and it didnt help..hes still dying.
    idk what to do anymore.
    how do you afford palladia? are there charities that help out? or do you have a highly successful occupation for yourself?

    idk what to do..i;d lie to try masivet…but it’s so pricey..even palladia is…i can;t believe he has grade cancer.

  33. martha main on November 29, 2010 at 1:41 pm

    My dog is currently taking 50 milligrams of masivet two tablets once a day. He is a jack russell and has been on this medicine approx. 5 months, he is 16 years old. All of a sudden the mass tumors are coming back and starting to burst, what is the best thing to do at this point? Can we up the dosage of the masivet? Please give me any advise if you can, Thank you

    • DemianDressler on December 8, 2010 at 9:01 pm

      Dear Martha,
      I am sorry to hear this. Your dog is coming out of remission and you need to go start a rescue protocol. Have you been feeding your boy the Dog Cancer Diet? I’d be using that, and I use Apocaps for my patients. There is a lot here that may not be addressed- you have read the Guide? If not, I would as it is an easy read with a ton of good info.
      all my best,
      Dr D

  34. c henshaw on September 29, 2010 at 6:55 am

    hi my dog sophie is 16 years old and has a mast cell tumour on her right hind leg. it has changed and enlarged in the last two weeks overall she has had it for approx 2 months. on monday the vet did a biopsy and says that there is nothing to be done. he says she probably has between 4 to 8 weeks at the most. i am at a loss to know what to expect as the vet vet just said ” we will know when the time is right to have her put to sleep” this i cannot envisage at the moment as she is eating well, going to the toilet as normal, and jumping up and down when going for a walk (except when raining, she hates the rain!) what can i expect to happen in the next few weeks? and will she be suffering? thanks for any advise

  35. Kristine on September 28, 2010 at 4:53 am

    My cat has cancerous mass cell tumors, all the work up showed that he is healthy but he is not eating or drinking, he was given shots and meds to help him eat but he is still not eating, he comes in the kitcken crying like he is hungry but he does not eat, I have been feeding him baby food and forcing him to drink water, how long is he expected to live?

  36. Ciapek's mom on September 1, 2010 at 2:26 pm

    My dog is 3 yrs old and he had is 3rd maste cell tumor removed.. this on was a grade 2 and was about 2inx2in back fo his ear flap.It was removed on friday august 27, 2010. He know has lots of discharge( where we have to use a warm cloth and help the fluid out) he is on metcam 40mg 1 day/ cephlex 500mg 2 tablets twice a day/ benadryl 50mg 3xs daily. he is also starting to loose his fur with sores….pls help…I despartly need info…we are scared that he my loose his life from this surgery…i took off work for 9 days to help my poor dog…. shoud i take him to a differnt vet…please help us from Edmonton, Canada…
    Thank you for looking at this…
    From Lucille ( Cipek’s mom)

  37. gina on August 4, 2010 at 3:44 pm

    hi i have a 4yr old red nose pit bull who very suddenly developed a large mass on his shoulder about a month ago. at first we thought that he had injured it when he stumbled on the steps the vet gave him some meds seemed to work for a while then it got bigger and he wasnt walking on his leg so i tok him back thinking now maybe someone had hurt him cause the vet still didnt think it was a tumor or anything did xray showed nothing did a slide saw no cells. it started going down somewhat then lastweek all came back bigger and badder then did a bio but that didnt even show it is a mast cell which is what they are thinking it is now they have said that maybe a sonagram would show more . i want to do all i can for him cause he is my baby my problem is i may be losing my job in the next few weeks ,is there any kind of dog program out there that could be of some sort of help any information would be wonderful thank you

  38. Teressa Abbott on July 18, 2010 at 10:12 am

    Dr. D:
    my 10 yr old Schnauzer Simon had a grade 2 mast cell tumor removed from his foot 2 weeks ago. My vet operated on it the first time and removed as much of the tumor as he could and realized it was wrapped around his toe (on his back foot). After the biopsy came back as a grade 2, a second surgery was done to remove the toe. It was a successful surgery with clean margins and no signs it has spread. His bloodwork also came back ok. Today, I discovered some sort of growth under his tail above his anus. What could this possibly be? Could it be another mast cell tumor? His appetite has been off and his stools are soft and runny. He was fine up until the first surgery and just hoping that the stress and meds have his digestive track off balance. He has been on chicken and rice for the past 3 weeks along with Flagyl (he has taken this for over 2 yrs for colitis), Amoxitabs which he finished a few days ago, Baytril which he is on for another couple of days. They also have him on a Probiotic paste. He has eaten ID the past 2 days, but not thrilled about it. He has had issues with his stomach off and on the past couple of yrs and was diagnosed with colitis or IBD. My main concern is this other growth I am seeing… he is intact also. Any input would be appreciated.
    Teressa Abbott

  39. Lynn B. on May 24, 2010 at 7:42 pm

    Dr. D:

    Our 15 1/2-year-old poodle, who is otherwise healthy, has a pea-sized mast cell tumor on the upper fatty portion of his right ear. We are advised to remove half his ear. He takes Atopica for previous skin allergies. His blood work is amazingly good. He eats and sleeps well and appears to be in no discomfort.

    An ultrasound of his abdomen reveals no other tumors are present. Tomorrow we will receive lump node results, which the doctors feel will be negative also. He has visited both an oncologist and a surgeon.

    I contacted Dr. Ahn who will allow our dog into the Masivet compassionate care program. My decision is are we best to do the surgery or fo with the Masivet only? Is partial pinnectomy inhumane for a 15-year-old? If we elect for surgery, the surgeon gives benadryl only at the time of the surgery. Should this therapy be started sooner?

    Your help is greatly appreciated.


  40. Scott on April 12, 2010 at 2:55 pm

    Thanks so much for getting back to me so quickly Dr. Dressler.
    I realize you cant give advice specific to my dog but I was wondering if you know of anyone using Masivet in conjunction with Lomustine/CCNU. Ive tried using the web and my access to databases to find anything but Im turning up nothing. Im trying to be a good advocate for Max’s health and of course with such an aggressive type of tumor recurring twice, being as aggressive as his health will allow might be the best option if there is some benefit to be gained.

  41. Scott on April 9, 2010 at 10:33 am

    Stuart and Kristen,

    Great to hear about your success with Masivet. I have a 6 year old siberian husky who has been battling MCT for better part of the last year his is also on his muzzle. Long story short he had surgery in November and margins came back clean but tumor was Graded III. We put off chemo because margins were clean as were his lymph nodes and mitotic index came back very low. Unfortunately his tumor returned in the exact same spot and in February we started vinblastine which seemed to be destroying the cancer that is until a week ago when he went from no visible tumor to a huge growth in a matter of days. Ive scheduled removal of this second tumor and his lymph node for monday and we are going to start Lomustine protocol. I am wondering how you gained access to the Masivet? I really dont like the chances Max has statistically with just surgery and lomustine and radiation unfortunately is not an option.

    Any advice for getting Masivet for my baby and if so approximately how much would his treatment cost?

    • Dr. Dressler on April 12, 2010 at 12:47 am

      Dear Scott,
      Have your veterinarian or oncologist contact Dr. Albert Ahn at AB Sciences in New Jersey to see whether your Husky can qualify for pre-FDA approval use of masitinib through the compassionate use program.
      Dr D

  42. Stuart & Kirsten on February 27, 2010 at 1:36 am

    8 weeks on and Lil is doing great. The tumor on her muzzel is not visible. The vets are very pleased, and so are we.

    Who knows what the future hold though?


  43. Stuart & Kirsten on January 19, 2010 at 2:00 pm

    Dr Dressler

    Thanks for you reply.

    I wish to give you an update. Lil has now been on Masivet for one week now and the results that we can see look very positive. The tumor on her muzzle has lost a lot of it`s size and is close to dissapearing to the naked eye. So far she she has had no adverse reactions to the drug and she is on a heavy dose. We vist the vet tomorrow and hope they confirm this is good news.

    If the tumor on her muzzle is shrinking, should any distant spread ( blood/ spleen)have similar results?

    We live in hope.

    Stuart, Kirsten and a woof from Lil.

    • Dr. Dressler on January 22, 2010 at 10:11 pm

      Dear Stuat, Kristen, and Lil,
      If I were to guess, I believe the answer is yes.
      Dr D

  44. Sharon on January 6, 2010 at 10:30 am

    Dear Dr. Dressler,

    My 11 year old lab Tucker has had 3 surgeries in the last 6 months to remove mast cell tumors around his tail and anal area. These were given a grade II rating. After the last surgery he developed perianal hepatoid gland adenoma. The oncologist said chemotherapy would not help this part of his condition and didnt think radiation would either. Is there anything that can be done to help with this? He is eating great and happy, playing, going to the bathroom fine, etc., but the tumors on his rear are bothersome to him. I do have him on Benadryl per my vets recommendation. I think the tumors have stayed the same size or even got smaller but are still uncomfortable for him. I’m feeding him a grain free kibble plus meat and extra veggies. He’s my best buddy and I’d do anything to help him. Any suggestions would be greatly appreciated!

  45. Niz on January 6, 2010 at 7:40 am

    My dog Nikki has been on Masivet for a couple of weeks now with no side effects yet. She has been on vinblastine and CCNU and prednicare for a few months but the mast cell tumor on her side kept growing back. I think Masivet is her last chance but I have been reading about Palladia and wondering if that is a better drug; does anyone know? There is now evidence of mast cell tumors in her liver too so am praying this will work. Any info would be great.

  46. Stuart & Kirsten on January 5, 2010 at 11:22 am

    My 9 year old Lab ( Lilly) was recently diagnosed with 2 mast cell cancers, one on her chest grade 2 and one on her muzzle (grade unknown).
    To cut a long story short she was to have the chest surgery redone to take a bigger margin and in my mind very radical surgery on her face. However on the day of the surgery bloods came back showing mast cells in the blood and spleen, however the vet could not confirm if this was bad news but he suspected distant spread of the disease. I always said if any tests proved the cancer had spread we would not perform surgery.
    We have taken the option of giving Lily Masivet, she will be the first dog in Scotland on the drug and we pray that it will help in some way. As I write we are waiting on the drug arriving from Paris. Does anyone have experience of Masivet?
    This festive period has been full of tears on this dreadful news.

    • Dr. Dressler on January 9, 2010 at 7:41 am

      Dear Stuart and Kirsten,
      I am sorry to hear this and the timing could not be worse.
      I have had some very good results with Masivet, either as remission or as stopping progression. My two cents!
      Dr D

  47. Silvia on December 7, 2009 at 6:38 am

    Hi, I’m writing from Italy. I confirm you that Masivet is available in Europe. My 4 yrs old cat has been living with mast cell tumor for a year now (and he was operated twice: the first time it was just a lump on the skin; the second time a lymph node was involved and if I hadn’t gone back to my old good veterinarian he wouldn’t probably be here anymore). I discussed with my vet the opportunity to use Masivet for my cat but he said that, at least in cats (anyway, it must be pointed out that Masivet hasn’t been approved yet for the treatment of cats) it’s not free from collateral effects (anaemia, vomiting, etc) as commonly stated. So, for now, I prefer to go on with palliative treatments and proper feeding.
    Greetings to you all.

  48. Anna on November 19, 2009 at 12:32 pm


    I think Masivet is only commercially available in Europe for the moment. It is supposed to be mostly well tolerated and quite efficient on some cancers.
    We shall see…

  49. Erin on November 8, 2009 at 10:59 pm

    I’ve read a lot about Palladia, but not much about Masivet. Do you have any information on this drug? I know it’s only available in Europe.

    We have an 11-year old Ridgeback who has had MCT for almost four years. He’s had 4 surgeries and 3-4 rounds of chemo (Vinblastine). He has many tumors – fatty and mast cell – which have been holding steady on Prednisilone and Denamarin (liver support) for nearly a year. But, in the last 3 weeks or so new bumps have been emerging and old ones are coming back. I will call our oncologist here in Portland tomorrow, but I wondered if you had any insight into Masivet.

    He gets Evo, grain-free, salmon oil, lots of chicken and eggs, lots of exercise (swimming is his favorite) and is in good spirits and generally full of beans. I’d like to keep it that way for as long as possible… Anything else you recommend giving him? I tried K-9 Immunity for a while, but it almost seemed to activate the tumors. We went to a holistic vet too for some time, incorporating a variety of tinctures, homeopathics and acupuncture. That didn’t seem to help.

    Thanks for any advice!

  50. Jesa White on October 28, 2009 at 11:09 am

    My 6 y/o male Doberman had a cough so the vet took a chest xray, it shows three large masses in or around the lungs. My boy has been eating and active. The vet and I were both taken by suprise at the results of the xray. My question is where do I go from here? The cough is from the growth pressing on his treachea. I’ve ordered K-9 immunity Critical care. what can I do for his diet?

    • Dr. Dressler on November 2, 2009 at 10:23 pm

      Dear Jesa,
      I am sorry to hear about this. Your veterinarian should be giving you some information (referral to an oncologist, getting a diagnosis on the masses and so on.) You need to establish what this is. Some ways of doing this are getting a wash of the lungs to see if the cells can be identified in the wash. Another is using the ultrasound to guide a needle into the growths possibly. Different tumors, different treatments. You should be educating yourself about the whole cancer picture, which is too much for a single blog post, I am sorry. I would suggest you get a copy of the e-book I wrote, take some time, and read it. Sadly there are no quick and easy answers that do your question justice. As far as diet goes, consider a slow transition to nd food (prescription), or a low carb, high protein, moderate fat diet with minimal preservatives and colorants. See the blog post on mast cell tumor diets as well and histamine.

  51. AZJoeyG79 on October 4, 2009 at 9:14 pm

    Dr. D,

    Tonight we found a mass the size of a plum on Oreo’s chest. He is a 14 year old male English Cocker Spaniel. He is partially deaf in one ear and pretty much blind in both eyes due to cataracts. He came into our home and family approximately five years ago from a relative in pretty good health. Whatever this is does not appear to be diminishing his appetite at all, and his behaviors are normal, except that he has been unusually “whiney.” We do not have funds available for extensive treatments, but we do not just want to “put him down.”

    Do you have any recommendations?

  52. Carrie on June 22, 2009 at 5:11 am

    Can a Vet remove a Mast Cell Tumor on a testicle, but not neuter the dog?

  53. carmen on June 12, 2009 at 6:31 am

    Dear Dr. Dressler,
    On May 2, I took my 10 yr. old lab mix to the vet for his regular check up. As the vet was checking him he found a lump in his rear that he called anal gland cancer and informed me that he needed and operation to remove it. The operation was scheduled and the vet informed me that he felt that it was successful and looked like a good out look. He sent the mass that was as big as a plum out and it was the type of cancer that he called it. My dog came home and he was fine and was his old self for a few days and I noticed that he was having trouble going up and down the stairs. The vet informed me that perhaps I should see a cancer specialist and we did. The vet did many test on my dog and concluded after she sent the biopsy out that the cancer had spread to the liver. She also added that perhaps it had spread elsewhere also. She informed that perhaps we could try chemo but felt that it might not work. The vet gave us what she perceived what might happen and informed me that we would eventually have to put him down. (devastating) I took my dog home and have proceed to make him as comfortable as possible.The vet gave us meds for my dog to take. My dog was alert, eating, barking and doing dog stuff. About a week ago I noticed that his hind legs were shaking and he dragged them. The next day he could not walk at all and has not walked since. I called the cancer vet and asked if the pain meds could do this and she informed me that she did not think so. The meds that he is taking are tramadol twice a day and Deramxx 25mg. I am in the process of taking him to a neurologist. In the mean time I have purchased a harness for his hind legs so that he can go out side and walk with our assistance. I am desperate to help him and as long as he is alert and not in pain I will not put him down. If you have any ideas I will try anything you suggest.
    Thank you, from all of the postings I see that you are very knowledgeable and have compassion and understanding of the love that a human can have for a pet.

    Hanks, mom.

  54. Anonymous on June 6, 2009 at 4:57 pm

    does anyone have an idea where i can purchase the new Cancer treatment drug for dogs (Palladia)

  55. Lauran on May 30, 2009 at 5:29 am

    The mass has been removed it was the size of a cantelope. He is only a small dog. The vet couldnt belive the size of it! He is going great, the pathology report thinks its nephroblastoma, but they say this is an unusal case, for some reason no one can pin point this tumor? We have been told that there is 50% chance that it can spread to distant areas, but also a 50% chance that it hasnt. We are going to put him on neoplaisine as a percautin, has any one used this?

  56. Lauran on May 23, 2009 at 3:45 pm

    I wrote on may 12th, since then the biopsy came back and the pathologist is not 100% of what kind of tumor it is. We have had a blood and urine sample done and Yoda is doing great, nothing has spread. Surgery is in 2days and the vet is confident that he will live to at least 12yrs old, apperantley this tumor is contained to one area and will not grow back. His will lose the right kidney, but his kidney function is normal. We are very happy that our puppy can be saved!

  57. will on May 20, 2009 at 5:55 am

    X-rays appeared to show a mass on my dogs spleen. My vet operated on her this morning for its removal but after opening her up found no mass anywhere, and bloodwork is unremarkable. how unusual is this? Please help. confused, Will

  58. Elya on May 19, 2009 at 11:10 pm

    My 9 year old cocker spaniel had a surgery on Saturday,mast tumor 1, on her neck.
    They did blood test and urine test first before the surgery. Surgery went fine, but the shaved area around removed tumor was very itchy and dog was scratching near stitching area a lot, I was able to stop her most of the time, but she ended up getting some stitches out and the vet had stapled one area 2 days later. Vet did not want to cover area with anything/ she said it would not heal , even i asked over and over. Dog started to scratch after that even more. Now staple is gone and most of the stitches…
    What could be done to protect that area?

  59. Lauran on May 12, 2009 at 2:20 pm

    My puppy (Yoda)is 8.5months old. A male yorkie cross with a mini schnauzer has a mass off his right kidney.We are still waiting for the biopsy but am wondering if anyone has any experience with nephroblastoma? This is what the vet thinks it may be.
    any help is well valued.


  60. Vie on May 7, 2009 at 9:09 pm

    Dear Dr. Dressler,

    My dog is going in for surgery on Tuesday for his mast cell tumor removal. I am aware that he had this tumor for a couple of years, but could not afford surgery… but I got referred to Care Credit and now I’m doing everything I can to make sure he’s ok. My dog is the same as always, always hyper and happy. The vet took X-Rays and there are no tumors present inside. He only has the one tumor on the outside by his belly.

    So my question is, even though he has lived with this tumor for a couple of years and was doing great, will things change after surgery? I’m very concerned that after removing his one tumor, it will cause more tumors to grow. I’m very anxious.

    Thank you.

    • Dr. Dressler on May 11, 2009 at 9:59 pm

      usually removal of a tumor does not increase the odds of other tumors, at least generally. At least the scales usually tip in the direction of benefit for surgical removal.
      Hope it turns out well. Make sure your trust of your vet is solid before the procedure.

  61. Katrina on April 15, 2009 at 7:50 am

    Dear Dr D,
    About 1 month ago my ridgeback hound/mix who is 10 years old was diagnosed with grade 3 mast cell tumor. I had them removed. And I recently took her to an oncologist who took a buffy coat blood test…it came back negative (good news!!). My dog has had a rough life with lots of knee and hip problems and I really dont want her to go through anymore pain. I am aware that theres only a 6 month life span if she does not get any chemo treatments. But, if I were to get her chemo treatments what is the expectant life span afterwards? Is it worth all the stress for her??
    Thanks Dr. D!

    • Dr. Dressler on April 15, 2009 at 9:54 pm

      Katrina, this is a complicated question with a long answer…I will answer in the webinar:

  62. jamie on March 22, 2009 at 4:04 am

    my bullmastiff has grade3 mast cell, only on the side of the body. Do you think I should bdo a bood test before a margin surgery and let it spread while opening him again?

    very confused.

    • Dr. Dressler on March 22, 2009 at 7:14 pm

      you need to get a recommendation from your vet about your particular dog. One needs to assess whether the cancer has spread before doing surgery. This is done with blood testing, urine testing, X-rays, ultrasound, lymph node aspirates, and possibly bone marrow testing and buffy coat smears. These are all ways to help see if it has already spread. If not, most grade 3 mast cell tumors should be removed and other ways of battling the cancer should be instituted. You can read more about this in the e-book- see
      Dr D

  63. patsi ringsdorf on March 9, 2009 at 7:13 am

    I have been using neoplasene since aug.1,2007have removed 14 plus tumors,just doing the best that I can,main thing is good QOL.

  64. Katie on March 9, 2009 at 6:56 am

    Hi Dr. D!

    I want to buy your book, but my husband is not a believer. You see our 4 year old female Boxer, Layla, was diagnosed almost 3 months ago with Stage 3 mast cell tumors in her lymph nodes. We’ve already spent thousands of dollars…

    We had one infected lymph node removed almost 3 months ago and during that time it spread to the lymph node right next to her colon. The doctor said they could not operate due to the location. She also sprouted two tumors on her nose.

    She was on IV chemo/prednisone treatments for her first 2 weeks, then her WBC were too low and she had to take time off. During 2 weeks with no treatment, the tumors on her nose started getting bigger again. The oncology vet said that she wanted to try a pill form of chemo because she was not seeing the best results from the IV form. Layla still seems to be in good spirits though.

    We are soo scared we are going to lose our baby! We are newlyweds, recently out of college so we do not have a large income and are getting discouraged about whether or not chemo treatment is the best treatment for Layla. The oncology vet, does not seem to ever have time to sit down and talk about functional supplements and of course she is the only one around.

    We have changed her diet to EVO Chicken kibble with 3 pumps of fish oil mixed with water; a daily multi-vitamin; K9 Immuno-modulation therapy by Aloha Medicinals; and Benadryl 3 times a day. I think she has been eating better than I have lately…But I am still not sure that we are doing everything we can.

    Questions to you:
    I want to try a vet who is more in to functional supplements. Do you think this is a good step to stop chemo and try supplements? or both?

    If I could persuade my husband into buying your book, does your book cover specific stage 3 mast cell tumor treatments?

    Dr. D, I wish I had all the money in the world so I could bring her to see you! From watching your video, you seem to have more compassion for animals then most vets.

    Thanks for being you!

    Katie from Tulsa, OK

  65. Mark Willis on February 28, 2009 at 10:57 am

    I have an 11 year old black lab that was diagnosed with Mast Cell tumors about 3 years ago. He has had several removed and the vet did not give him a good prognosis. He has been on prednisone, dosing him with approx 80 mg per week and has been doing ok considering. Lately, he is getting very lethargic and unresponsive. Should I also dose him with benadryl? I can’t tell if he is in pain and don’t know how long I should let this go before I consider putting him down. I am looking for any input to make his last years worth living but don’t want him to live with constant pain and misery.

    • Dr. Dressler on March 7, 2009 at 4:36 pm

      you should check out the post on pain control, life quality, and other dog lovers comments on those posts. Consider benadryl, doxycyline, cimetidine, metacam, possibly gabapentin, and others meds with your vet.

  66. Cathie on February 26, 2009 at 2:27 pm

    My dog is having surgery tomorrow tomorrow and I am going to give him a benadryl tablet 1 hour before surgery. Is that enough?

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