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

Be Careful What You Read!!

Updated: November 14th, 2018

One of the difficulties dog lovers have is in getting good data about dog cancer. Sometimes questions surface after your visit to the vet or oncologist, and you may not be able to reach your dog’s doctor.

Logically, the internet is a good place to start.

You will find lots of information about dog cancer on line.  However, not all of it is true, and some may lead to incorrect conclusions.

These conclusions can create false hopes by appealing to the need for a good outcome.  Other times, deliberate paranoia or even intentional hysteria geared towards product sales is the goal.

You would be surprised what you find.

Suddenly, I have noticed a crop of Dog Cancer Survival Guide imitations popping up.  Although it is flattering, I am concerned. None are written by an actual vet, although one “Doctor”  is a chiropractor (for people).  I mean, I have absolutely nothing against chiropractors (I have gotten my back worked on before), but…

It would be funny except that concerned dog lovers are taking advice that may not help, and could even harm.

I just read an article on the CBS News Health page about dog skin cancer.  It was very surprising, considering the source. There were a few points that were quite misleading that should be cleared up.

For example: “.. mast cell tumors, are fatal if untreated…” This is not necessarily true. Here is an abstract supporting the fact that some are dangerous and some are not.  There are very few grade 1 mast cell tumors that are fatal if left untreated. (Mast cell tumors are graded from 1 to 3, with some of grade 2 and  all of grade 3 being particularly dangerous. For more on mast cell tumors, check out this week’s webinar by clicking here).

Here’s another excerpt from the same site:  “Mast cell tumors:…the hormones estrogen and progesterone may also affect cancer growth.”  This states that estrogen and progesterone affect mast cell tumor growth.  Not true.  This abstract shows that there is no link between estrogen receptors and mast cell tumor behavior in the dog.

This same “information”  in the CBS News Health site suggests that spaying a female dog would be beneficial to dogs with mast cell tumors, to remove these hormones.  False.

On the other hand, these hormones have real-life, measurable effect on mammary (breast) cancer in dogs which is well documented and common knowledge. Spaying does influence mammary tumor development in the dog.

So please be careful what you read!

All my best,

Dr D

Leave a Comment





  1. Joan Korth on May 13, 2019 at 3:58 am

    Dr Dressler, My shih zu is 12 and had a mast cell tumor larger then golf ball removed in November and staged at 2-3. It was just under his clavical. He now has one just above shoulder larger then first one. If I do nothing, as I believe a 2nd surgery won’t help and chemo and radiation is drastic extremes giving poor quality of life, what should I expect. I ordered antihistamine treats and a holistic treat with antioxidants to give him and maybe some CBD oil.
    Can you help me with some direction and what to expect? He loves to eat, all body functions right now are perfect. He just sleeps a lot. It’s hard knowing what may be around the corner. Rowdy has been a loyal and great friend. Thank you.

    • Dog Cancer Vet Team on May 13, 2019 at 8:51 am

      Hello Joan,

      Thanks for writing and we’re sorry to hear about your boy. As Dr. D writes in the Dog Cancer Survival Guide, there are a number of things that you can do to help your dog under your vet’s supervision. Conventional treatments (chemo, surgery, and radiation), nutraceuticals, immune boosters and anti-metastatics, diet, and mind-body strategies. This is what he calls the Full Spectrum Approach to Dog Cancer Care.

      It sounds like your boy’s quality of life is important to you, so you may find these articles on how to provide comfort to be helpful.

      We understand that it can be really difficult knowing what can happen and you may be wondering what to expect. Molly wrote an amazing article on warning signs that you may find beneficial in answering some of your questions.

      Also, you may want to have a look at food and nutrition for dogs with Mast Cell Tumors because dogs with MCT need a low-histamine diet.

  2. Mary on March 26, 2012 at 4:55 am

    Hi Dr. Dressler,
    First, I want to thank you for everything you do for our dogs and for us. You and your Dog Cancer Survival Guide/blog helped me so much as my Brittany, Hannah, struggled with Hemangiosarcoma. We lost her in August, after a long journey with this horrible disease. Her last 6 months of life–although painful due to surgery and chemotheraphy–were actually some of the best. I completely changed her diet, had her on fabulous supplements…the bottom line is that she felt great most of the time. More like a puppy at age 10 than she’d been in years. Now that our journey with Hannah is over, we’ve opened our hearts and home to a new Brittany. Gracie is 7 months old, and she is benefitting from all of the diet and lifestyle knowledge we gained through Hannah. One of the lessons we learned was that there is an increase in the Hemangiosarcoma rate in female dogs that are spayed early. May I ask you if this finding is still believed true? I know you cited it at one time, but I’m wondering about your current recommendations for spaying. I’m doing everything I can to prevent the same thing happening to Gracie that happened to Hannah. I of course know that there were many, many factors that led to Hannah’s development of Hemangiosarcoma, but if there’s any way of preventing it in Gracie, I want to make sure I do it.
    I apologize for the long-winded question! But I would really appreciate any guidance you can give me.
    Again, thank you so very much for your support of those of us living with this horrible disease. God bless you!

  3. Dr. Dressler on September 29, 2009 at 9:58 pm

    Will, I am sorry to hear this story. Awful.
    I was reading your comment and realized you were thinking I was promoting animal treatments by those without the training. On the contrary, I agree with everything you pointed out. My admission to having my own back adjusted (which makes me feel good sometimes when I get tight) in no way was meant to support those without training giving medical recommendations.
    Thanks for your comments and for allowing me to clarify!
    Best,
    D

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