Take a look at how conventional and alternative therapies can work together to combat cancer in dogs and cats.

Talk to any animal lover, and chances are you’ll find that most have at one time or another had to cope with cancer in their canine or feline companions. As with humans, cancer is one of the most common diseases in dogs and cats. In the first of this two-part series (Volume 8, Issue 3), I discussed the causes of cancer and a few of the more commonly seen cancers in animals. In this article, I’ll discuss some of the conventional and complementary therapies used in treating these and other cancers.

Conventional Treatments can be the First Line of Defense

Even though I’m a holistic veterinarian, I believe in using conventional therapies when they are appropriate. In fact, I see the best results when I integrate conventional and complementary therapies. Conventional cancer therapies, including surgery, chemotherapy, and radiation therapy, can quickly kill cancer cells, so I do advocate their use in treating animals with cancer. The goal of these therapies is to reduce the number of cancer cells left in the body. When I then prescribe natural therapies to boost the animal’s immune system, there are consequently fewer cancer cells left for the immune system to kill.

Each oncologist has his or her own favorite protocols based upon clinical experience. In general, some combination of surgery, chemotherapy, and radiation may be chosen, depending on the type of cancer. While humans often suffer debilitating side effects from these therapies, these effects are extremely rare in animals. Using complementary therapies in conjunction with these conventional treatments reduces the incidence of side effects even more.

Complementary Cancer Therapies

Hundreds of complementary therapies may be useful in treating animals with cancer. As is true with conventional treatments, every holistic veterinarian has his favorite supplements and brands. Regardless of which ones are used, integrating a complementary with a conventional approach has four goals:

  • To make the animal feel better.
  • To help the animal live longer.
  • To minimize side effects from conventional therapies.
  • To boost the animal’s immune system to help fight off cancer.

It’s important to realize that regardless of how much chemotherapy is used to poison the cancer, how much surgery is done to cut out the cancer, or how much radiation is used to burn out the cancer if the animal’s immune system is not functioning properly, the animal will die much sooner!

Here are some complementary therapies I use to treat my own cancer patients:

Fatty Acids

Omega-3 fatty acids – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – are derived from algae or the oils of coldwater fish (salmon, trout, or most commonly, menhaden fish). They reduce tumor development. DHA specifically has been shown to promote cellular immunity, reduce inflammation, inhibit tumor growth, and decrease the spread of cancer (metastasis) by decreasing the formation of new blood vessels necessary for cancer to grow and spread (angiogenesis). Combining DHA with the chemotherapy drug paclitaxel has allowed researchers to use higher doses of the drug without signs of toxicity. The DHA-paclitaxel combination also allowed the drug to work longer in the body than when the drug was administered on its own.

Research has shown that dogs with lymphoma enjoyed increased survival when a diet high in omega-3 fatty acids (fish oil) was combined with conventional chemotherapy, as opposed to dogs with no dietary modifications. Supplementation with omega-3 fatty acids also reduced radiation damage in the skin.

Omega-3 fatty acids have also been found to inhibit matrix metalloproteinase (MMP) enzymes, which play a role in how cancer cells survive and spread in the body.


Specific chemicals function in the body to reduce oxidation, a process that occurs within the cells. Oxidation creates cellular by-products, such as peroxides and free radicals, which accumulate in the body and are toxic to the cells and surrounding tissue. The body removes these by-products by producing additional chemicals called antioxidants.

High doses of antioxidants have a different effect on cancer cells than they do on normal cells. Cancer cells have a greater ability to take up these higher concentrations of antioxidants. This inhibits the cellular processes necessary for growth and reproduction and results in the cells’ early death.

A major cause of death in cancer patients is nutritional depletion. Antioxidants and a proper diet can help boost the patient’s nutritional status and decrease the chance of early death due to tissue starvation.

Many different antioxidants can be used to supplement animals, including vitamins A, C, and E, and the minerals selenium, manganese, and zinc. Other antioxidants, including superoxide dismutase, glutathione, cysteine, coenzyme Q10, Ginkgo Biloba, bilberry, grape seed extract, and pycnogenol, may also be helpful. Each of these works in specific ways. In general, antioxidants minimize side effects from conventional therapies while maximizing their effectiveness.

Immune-Boosting Supplements

A large number of supplements can boost the immune system in animals with cancer, but here are just two that are particularly potent:

1. Arabinogalactans are a class of polysaccharides derived from the larch tree, mainly the western larch (Larix occidentalis). They inhibit the chemical reaction that allows cancer cells to spread to the liver, and thus have strong immuno-stimulating and anti-inflammatory properties. Arabinogalactans are also an excellent source of dietary fiber and have been shown to increase the production of short-chain fatty acids, principally butyrate, a nutrient that plays a particularly important role in the colon. They may be useful for the treatment of animals with diarrhea and as protection against cancer-causing compounds. Arabinogalactans have been shown to stimulate natural killer cell activity as well as the immune system and to block the spread of cancer cells. They are also recommended for decreasing liver metastasis and for treating liver tumors.

2. Green tea contains high levels of polyphenols (catechins), known to possess strong antioxidant, anticarcinogenic, and even antibiotic properties. The four major green tea catechins are epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (EGCc), the most potent and physiologically active antioxidant of the four.

Giving green tea with the chemotherapy drug doxorubicin enhances the effects of the drug, decreases the heart toxicity often seen with doxorubicin administration (by decreasing doxorubicin concentration in the heart cells), and increases doxorubicin concentration in cancer cells.

Slowing Cancer Seems to be Related to:

  • Antitumor activity by inhibiting urokinase (uPA, an enzyme used by human cancers to invade cells and spread)
  • Inhibition of DNA damage (especially from peroxynitrite, a potent free radical that isn’t stopped by most antioxidants)
  • Activation of the suicide gene (causing cancerous cells to die)
  • Prevention of iron absorption (when taken with meals)
  • Inhibition of angiogenesis (the formation of new blood vessels used by cancers to grow and spread)
  • Inhibition of vascular endothelial growth factor
  • Inhibition of an NADH oxidase known as quinol oxidase or NOX. NOX activity is needed for the growth of normal cells, but an overactive form of NOX called tNOX allows tumor cells to grow. The EGCc in green tea inhibits tNOX but not NOX.

As you can see, there are many possible therapies to choose from when treating a dog or cat with cancer. Since each animal is an individual, however, it’s important to work with your veterinarian to determine the best possible therapy for your beloved companion.

Homemade Anti-Cancer Diet for Dogs

This diet is high in protein and fat, which is just what is required by dogs with cancer. Check with your veterinarian to see which diet is best to feed your dog.

  • ½ pound ground meat (turkey, chicken, lamb, or beef)
  • ½ cup potato (cooked with the skin) or brown rice
  • 4 tsp chicken fat, canola oil, or olive oil
  • 1/8 tsp potassium chloride (salt substitute) or 1/10 tsp salt
  • 1 multivitamin-mineral supplement

This recipe provides 775 kcal and supports the daily needs of a 25-pound dog. It also provides 43.9 g protein and 22 g fat.

Recipe Options

  • Adding 2 tbsp canned sardines increases the protein content by 6.2 g and the fat content by 4.6 g.
  • Arginine can be added at 647 mg/100 kcal of food.
  • Omega-3 fatty acids (fish oil) can be added (at 1,518 mg EPA/DHA/100 kcal). This is very difficult to do because the average omega-3 fatty acid capsule contains 180-300 mg EPA/DHA. Work with your doctor to increase the fatty acid content as much as possible (adding fish such as salmon to the diet can help achieve this goal).
  • ½ cup raw tofu and 1 cup cooked lentils can be substituted for the ground meat.
  • Adding fresh raw or steamed vegetables can increase the level of natural vitamins and minerals, as well as add flavor. Most vegetables provide approximately 25 kcal per ½ cup.
  • For calcium and phosphorus, add 4 bonemeal tablets (10 grain or equivalent) or 1 tsp bonemeal powder, along with a multivitamin and mineral supplement.

From the book Preventing and Treating Cancer in Dogs, Copyright ©2006 by Shawn Messonnier, DVM. Reprinted with the permission of New World Library, Novato CA. www.newworldlibrary.com