Hi Tara, Kudos to you for being so thoughtful for a four-legged member of your family. Too many of us, myself included, fail to be thoughtful enough about the health of our family, for our two-legged and four-legged members alike. However, looking back, I don't think you'll ever regret any time and effort expended on that front.

As regards your question, unfortunately I don't think it's possible to make sure tumors don't come back. And your question is a simple one that I think calls for a very complex answer. However, here are some things that I think would be likely to reduce the odds of them coming back and improve her prognosis if they do. Incidentally, I think learning about these things will help you better protect yourself and other members of your family, too.

First of all, it's been said by cancer experts I respect that cancer is primarily a disease of the liver. So don't use Front Line or any other chemical(s) on her to control fleas and ticks. Instead, use a garlic and brewer's yeast alternative like one of those available from SpringTime or available on Amazon along with regular inspections when she returns from outside for fleas or ticks.

Second, do many of the same things you might do if it were for another two-legged member of your family including:

(A) Give her enough iodine. This is a relatively complex topic, but a very important one. So please research and educate yourself about it first. A good place to start, I think, is to do a search for Iodine on EarthClinic.com and read those posts and also to go to the following links:

Http://www.globalhealingcenter.com/natural-health/8-things-to-know-iodine-deficiency-dogs/

Https://www.youtube.com/watch?v=H_I9PLUg0lM

One of the complications is that iodine supplementation should be accompanied by the supplementation of certain other minerals, including organic selenium, magnesium, and zinc and adjusting the dose given weight and species factors. I also recommend that you try supplementing with it yourself first. I gather that, as a female, there's a 90-95% chance that you're deficient and can dramatically enhance the quality of your own life and reduce your odds of getting cancer by doing so.

(B) Supplement with boron using Borax dissolved in water. Again, I recommend researching it carefully and using it yourself first.

(C) Don't give her water from the tap with its chlorine, fluoride, and other toxins. And speaking of water, I would periodically add a tiny amount of hydrogen peroxide into it. And I would periodically add a tiny bit of Bentonite clay into her food.

(D) Since she's so much closer to the ground, don't make her breathe in the phytoestrogens in pesticides. So se only natural pesticides in the house and the yard.

(E) Foodwise... Feed her organic dog food. Don't add to her toxic load by giving her canned dog food with its BPA's and using glass bowls for her to eat from or store any food that you're going to give her, never plastic. And take a page from the most successful cancer therapies (including Gerson and Budwig) and reduce or eliminate meat and dairy in her diet. Also, as often as possible, include some fresh organic flax oil with her food. (I strongly recommend familiarizing yourself with those therapies and their diets, too.)

(F) Figure out one or more ways for her to get regular exercise that increases her heart rate and helps her get oxygenated.

(G) Since mold so often causes cancer, make sure she's in an environment that has as little mold as possible. Washing the floors periodically with white vinegar and/or Borax will reduce her mold exposure and reduce her exposure to the toxic chlorine and other toxic substances in the vast majority of commercial cleaning products.

(H) Super important: Religiously exclude sugar and corn syrup from her diet. As I recall, there are multiple studies showing something like double the number of metastases in populations with diets including sugar and corn syrup versus populations with diets excluding those items.

(I) Regularly add hydrochloric acid and a digest enzyme (preferably) pork pancreas to her food.

(J) Keep her stress level down and keep giving her lots of love.

That's all I can think of for now. Needless to say, please research and confirm that none of the preceding items are contraindicated for dogs. And you don't have to do all of the preceding items, although I think each of them would reduce the odds of a recurrence. But you asked. And like I said, it's a simple question that I think calls for a very complex answer. In any case, kudos to you again for being so thoughtful.

All the best,

Harry

P.S. The developer of Gerson Therapy, Max Gerson, found that every oil except flax oil promoted cancer in cancer patients he was treating (for active cancer).

P.S. As regards flaxseed oil, for human cancer patients, the Gerson therapy protocol includes two tablespoons of flaxseed oil per day for the first month and then one tablespoon for the balance of the therapy. However, healing legend Charlotte Gerson says it's important to get a mix of high quality oils thereafter to avoid getting, in effect, an overdose of flax oil and becoming allergic to it. She talks about that briefly (from 55:39 to 59:04 of the video below):

https://www.youtube.com/watch?v=aYYlX8aRj3E&list=PLnYZ4DNk61XJq4cSKm_eZZ4CLdtfAdrRW

To learn more about Gerson therapy, I highly recommend watching some of her videos on YouTube and then getting your hands on one or more of her excellent books through www.gerson.org, www.gersonmedia.com, or directly from Amazon.

If you're interested, the Gerson organization can probably also hook you up with others who have dealt with their dogs having cancer and/or mast cell cancer tumors.

My favorite Gerson books:

Max Gerson's classic, A Cancer Therapy: Results of Fifty Cases and the Cure of Cancer by Diet Therapy: https://www.amazon.com/Cancer-Therapy-Results-Fifty-Advanced/dp/0961152621/ref=sr_1_6?ie=UTF8&qid=1484495273&sr=8-6&keywords=gerson+therapy

Charlotte Gerson's "complete guide to the theory and practice of the Gerson Therapy", Healing the Gerson Way: Defeating Cancer and Other Chronic Diseases: https://www.amazon.com/Healing-Gerson-Way-Defeating-Diseases/dp/0976018624/ref=sr_1_2?ie=UTF8&qid=1484495273&sr=8-2&keywords=gerson+therapy