DoggoChef Logo Full Transparent Rectangle (600 x 172) | Premium Raw Food for Cats and Dogs | Raw Dog Food | Raw Cat Food | Raw Food for Pets | BARF | PREY | PMR

Cancer in Pets

Table of Contents

(Original Article Published via

The Role of Nutrition in Cancer Patients

Cancer is becoming a more commonly diagnosed condition in both dogs and cats. According to the National Cancer Institute (NCI) in the United States, the top five cancers in huumans are breast cancer in women, prostate cancer in men, followed by lung cancer, colon / rectal cancer, and melanoma in both sexes (see: Common Cancer Types (NCI)).

When it comes to our pets, there is no national organization that tracks the occurrence of cancer. We do know that many common huuman cancers are not prevalent in pets, but there are other cancers we do acquire in common (see: The Top 10 Warning Signs of Cancer, Dr Becker (Mercola)), including breast (mammary gland) cancer, lymphoma, skin cancer that takes the form of mast cell tumors in pets, and bone cancer. The rapidly growing specialty of veterinary oncology provides caregivers the choices to battle cancer that are similar to those offered huuman family members, so until recently, dietary therapy has often been neglected for pets with cancer, yet feeding them the proper diet is extremely important.

Studies demonstrate that both people and pets with inadequate nutrition cannot metabolize chemotherapy drugs adequately, which predisposes them to toxicity and poor therapeutic response. This makes proper diet and nutritional supplements an important part of cancer therapy.

Several metabolic derangements are common in the cancer patient. First, cancer patients often have hyperlactatemia (increased lactic acid in the blood). In addition, since metabolism of simple carbohydrates produces lactate, a diet with minimum of these carbs might be preferred.

Research has shown a pronounced decrease in certain amino acids such as arginine in the plasma of cancer patients. If left uncorrected, these amino acid deficiencies could result in serious health risks to the patient.

Weight loss often occurs in cancer patients, as a result of cachexia (wasting). Most of the weight loss seen in cancer patients experiencing cancer cachexia occurs as a result of depleted body fat stores. Tumour cells, unlike normal healthy cells, have difficulty utilising lipids for energy. Dogs with lymphoma fed diets high in fat had longer remission periods than dogs fed high carb diets.

The use of Omega-3 fatty acids can promote weight gain and may have anticancer effects and warrants special mention. In people, the use of omega-3 fatty acids, such as those found in fish oils, improve the immune status, metabolic status, and clinical outcomes of cancer patients. These supplements also decrease the duration of hospitalisation and complication rates in people with gastrointestinal cancer. In animal models, the omega-3 fatty acids inhibit the formation of tumours and metastasis (spread of cancer). Finally, in addition to having anti-cachetic  (anti-wasting) effects, the omega-3 fatty acids can reduce radiation damage to skin.

While many treatment options are often available for the various malignancies our fur kids experience, doctors sometimes overlook the simple aspect of nutrition. In the next decade, prevention and treatment will most likely include a focus on nutrition in veterinary medicine, just as their counterparts are now doing in the human medical field.

While there are no controlled studies showing the value of diet in supporting the pet with every type of cancer, there are studies (see: Using Alternative Therapies to Fight Cancer, Dr. Becker (Mercola)) showing the benefits of dietary therapy when combined with conventional therapies in dogs with lymphoma and nasal tumors.

What Causes Cancer?

A common question among pet parents is What causes cancer? There are actually several recognized causes of cancer in pets today.

  • Viruses. In cats, the feline leukaemia virus, feline sarcoma virus, and feline immunodeficiency virus directly or indirectly, through suppression of the immune system, cause cancer.
  • Toxins. In dogs, exposure to certain chemicals, including 4-D can cause cancer. Various food additives (see: Prescription Pet Foods Found To Contain Cancer Causing Toxins, Dana Scott (DNM)) have also demonstrated carcinogenic (see: Why Are Pet Foods Making People Sick? Dr Jodie Gruenstern (DNM)) activity in laboratory animals, prompting many owners and guardians to prepare food at home or select diets such as biologically species appropriate raw food that do not contain these synthetic additives and preservatives.
  • Vaccinations (see: Vaccinations in Veterinary Medicine: Dogs and Cats (Article)). Veterinarians are now beginning to realize that in a small percentage of cats, frequent immunizations may cause certain solid tumors to develop. This is a highly controversial topic (see: How Much Money are You Wasting on Pet Vaccines? (Mercola)), and the exact reason why a small number of cats who receive vaccinations (or other injectable medications) develop cancer is not known. Current evidence suggests that in genetically susceptible pets, some component of the vaccine, or of any injection, may cause a local reaction that becomes cancerous. However, there is concern among many veterinary professionals that vaccination is a risk factor for serious autoimmune diseases such as the potentially fatal canine disorder known as autoimmune haemolytic anaemia (AIHA). The symptoms of the feline virus pan leukopenia are GI-related and include intense and rapid onset of vomiting and diarrhoea, as stated above. Canine parvovirus has similar symptoms. Pets are routinely vaccinated (see: How Often Should You Vaccinate Your Cat or Dog?, Dr. Ronald Schultz (Mercola)) for both these diseases, and the incidents of inflammatory bowel disease (IBD), a chronic autoimmune disease of the intestines, has been rapidly increasing in both cats and dogs. Coincidence?
  • Genetics. Some pets are genetically prone to cancers (see: The Link Between Cancer and Your Pet’s Size and Color, Dr Becker (Mercola)). For example, amongst dogs, the Boxer is well-known to develop cancers at a much higher rate than many other breeds. Large breed dogs such as Retrievers have a higher incidence of malignant tumors of the spleen and liver. These examples may be the result of the in-heritability of certain types of cancers, similar to the situation that occurs with some types of cancers in people.
  • Aging. Most cancers occur in older pets. The exact reason is not known, but it seems that these older pets may have decreased functioning of the immune system.

According to Colorado State University’s Flint Animal Cancer Centre , the top 10 warning signs of cancer in pets are:

  • Unusual swellings that don’t go away or that grow. The best way to discover lumps, bumps, or swelling on your dog or cat is to pet him.
  • Sores that won’t heal. Non-healing sores can be a sign of infection or cancer and should be evaluated by your veterinarian.
  • Weight loss. Illness could be the reason your pet is losing weight but isn’t on a diet.
  • Loss of appetite. Reluctance or refusal to eat is another sign of possible illness.
  • Bleeding or discharge. Bleeding can occur for a number of reasons, most of which signal a problem. Unexplained vomiting and diarrhoea are considered abnormal discharges, as well.
  • Offensive smell. An unpleasant odour is a common sign of tumours of the anus, mouth, or nose.
  • Difficulty eating or swallowing. This is a common sign of cancers of the mouth or neck.
  • Reluctance to exercise or low energy level. This is often one of the first signs that a pet is not feeling well.
  • Persistent lameness. There can be many causes of lameness, including nerve, muscle, or bone cancer.
  • Difficulty breathing, urinating, or defecating. These symptoms should be evaluated by your veterinarian as soon as possible.

If you see any of these signs in your dog, it’s important to make an appointment with your veterinarian as soon as possible. Many of the symptoms of cancer are also present with other diseases. Blood tests to detect certain kinds of canine cancer are available and continue to improve.

When reading Dr Shawn Messonnier’s booked titled “Natural Health Bible for Dogs and Cats“, you will realise that alternative therapies such as dietary therapy, herbal therapy, homeopathy, and nutritional supplementation are often used very successfully to help treat cancer when combined with conventional therapies such as surgery, chemotherapy, and radiation therapy.

Is it Possible to Treat Cancer with Food?

There are many theories (anecdotal, medical, scientific and conspiracy) regarding cancer in pet parents and pets alike. We cannot speculate on these, as we do not have the medical or scientific background. We can only attest based on our own experience with fooding many fur kids with various heath issues and medical ailments.

In 1924, Otto Warburg (see: Wikipedia) theorized cancer feeds on sugar (the metabolism of tumours and the respiration of cells, particularly cancer cells), which is what carbohydrates become during digestion. His theory supports the notion that cancer cannot process fats well. He made some ground-breaking discoveries about the mechanisms of cancer, especially about respiration and mitochondrial malfunction.

In technical terms, Warburg hypothesized that cancer growth is caused by tumour cells generating energy (as, e.g., adenosine triphosphate / ATP) mainly by anaerobic breakdown of glucose (known as fermentation, or anaerobic respiration). This contrasts with healthy cells, which mainly generate energy from oxidative breakdown of pyruvate. Pyruvate is a product of glycolysis and is oxidized within the mitochondria. Hence, according to Warburg theory, cancer should be interpreted as a mitochondrial dysfunction. There is much available on the internet you can read on this topic.

One must remember that cancer, above all other diseases, has countless secondary causes. But, even for cancer, there is only one prime cause. Summarized in a few words, the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar.

— Otto H. Warburg

Warburg continued to develop the hypothesis experimentally and gave several prominent lectures outlining the theory and the data.

Today, mutations in oncogenes and tumour suppressor genes (rogue DNA) are thought to be responsible for malignant transformation, and the metabolic changes Warburg thought of as causative, now are considered instead, to be a result of these mutations.

However, recent re-evaluation of the data from nuclear / cytoplasm transfer experiments, where nuclei from cancer cells are placed in normal cytoplasm and where nuclei from normal cells are placed in cancer cytoplasm, more strongly supports Warburgs original theory than the somatic mutation theory for the origin of malignant transformation and cancer.

Dr. Thomas N. Seyfried (Ph.D.) , widely considered the godfather of the nutritional treatment of cancer, joins a growing number of researchers who say the high fat, low carb diet can treat many forms of cancer. And this is an important point, many, but not all, forms of cancer. This is because nearly all the healthy cells in our body have the metabolic flexibility to use fat, glucose and ketones to survive, but cancer cells lack this metabolic flexibility and require large amounts of glucose and cannot survive on ketones.

Boston College Biology Department Faculty, Prof Thomas N. Seyfried

Dr Seyfrield theorise that by limiting carbs, we can reduce glucose and insulin, and thus restrict the primary fuel for cancer cell growth. And the challenge with todays McKibble and McCan is high content of carbs, of course. Anywhere between 40% to 60% in a bag of McKibble is carbs, which becomes sugar once consumed. And the reason we advocate food over feed is simply low, to negligent, levels of carbs when fooding on real food. Watch this video from Dr Seyfried on the topic, titled “Cancer: A Metabolic Disease With Metabolic Solutions“.

While food plays an important role in preventing some cancers, the therapeutic value of food in treating existing cancer is less clear (for example, pancreatic cancer and high fat diets). It is true that a person with cancer needs excellent nutrition to better cope with the physical demands of the illness and the rigours of medical treatment.

Read More: Pet Food Formulas from the WISDOM of TCVM , (PetTAO)

In our minds, claims that foods, vitamins or micronutrients can kill cancer cells should be viewed in the context of the claim. This is simply because there are many different cancers, just download the ebook from Drs Marc Smith (DVM) & Casey Damon (DVM) on this topic . To date, there is little scientific evidence or applicable public domain research that a food or supplement can cure cancer or destroy cancer cells. But, this might also just be due to lack of research! How else would BigPharma keep on rewarding their shareholders?


“Ketosis” (Wikipedia) is a word you’ll probably see when you’re looking for information on diabetes or weight loss. Is it a good thing or a bad thing? That depends. Ketosis is a normal metabolic process, something your body does to keep working. In pet parents, when it doesn’t have enough carbohydrates from food for your cells to burn for energy, it burns fat instead. As part of this process, your body makes ketones.

If you’re healthy and eating a balanced diet, your body controls how much fat it burns, and you don’t normally make or use ketones. But when you cut way back on your calories or carbs, your body will switch to ketosis for energy. It can also happen after exercising for a long time and during pregnancy. For per parents with uncontrolled diabetes, ketosis is a sign of not using enough insulin.

Read More: What You Should Know About Diabetic Ketoacidosis, (WebMD)

However, ketosis can become dangerous when ketones build up. High levels lead to dehydration and change the chemical balance of your blood. Ketoacidosis is what happens when ketosis goes too far. Ketones build up in your blood, and it becomes acidic. Ketoacidosis can cause a coma or death.

Ketosis is also a popular weight loss strategy for pet parents. Low-carb eating plans include the first part of the Atkins diet and the Paleo diet, which stress proteins for fuelling your body. In addition to helping you burn fat, ketosis can make you feel less hungry. It also helps you maintain muscle.

Doctors may put children who have epilepsy on a ketogenic diet, a special high-fat, very low-carb and protein plan, because it might help prevent seizures. Adults with epilepsy sometimes eat modified Atkins diets. Similar research was done in dogs with epilepsy .

Read More: Ketogenic Diet Linked to Seizure Reduction in Dogs with Epilepsy, Amy Karon, (Article)

Some research suggests that ketogenic diets might help lower your risk of heart disease. Other studies show specific very-low-carb diets help people with metabolic syndrome, insulin resistance, and type 2 diabetes. Researchers are also studying the effects of these diets on acne, cancer, polycystic ovary syndrome (PCOS), and nervous system diseases like Alzheimer’s, Parkinson’s, and Lou Gehrig’s disease. However, studies outside of these areas, and in companion animals, are very limited.

For healthy people who don’t have diabetes and aren’t pregnant, ketosis usually kicks in after 3 or 4 days of eating less than 50 grams of carbohydrates per day. That’s about 3 slices of bread, a cup of low-fat fruit yogurt, or two small bananas. You can start ketosis by fasting, too. And if you follow the principles to fooding your pets by fasting one day a week, you are, in theory, already supporting them through ketosis.

However, it is also believed that dogs (as carnivores) are very well adapted for fasting for reasonably long periods of time, and thus the essential biochemical changes caused by changing to a high fat and low carbohydrate diet in humans cannot be manipulated in dogs. What we do need to acknowledge, is that the way we, pet parents, metabolise our food is very different to the way our fur kids metabolise theirs.

Supplements are not the answer!

Supplements with the deficient amino acids might improve immune function and positively affect treatment and survival rates. However, results of studies that show a protective effect of foods containing certain nutrients should not be taken to mean that these nutrients, when isolated and taken as supplements, will provide the same benefits for cancer prevention. Why? Because they become food fragments.

In some cases, there has been an increased risk of cancer in those pet parents who take nutrient supplements at doses higher than the usual amount of that nutrient normally eaten in foods. For example, the use of beta-carotene and vitamin E supplements has not been proven to be effective in either prevention or treatment of lung cancer. In fact, several studies have shown that beta-carotene supplements increase the risk of lung cancer in people who smoke.

So, Can we Treat Cancer With food?

Where we do agree, is that there can be absolutely no debate that poor diet is a contributory factor in the cancer forming process. Cancer development is a complex issue and involves a multi-step process. It does not happen overnight. Many factors may combine and in a way that is as individual as you are. Everyday each of us makes cancer and pre-cancer rogue cells as by-products of our metabolism. These are normally killed off by a healthy immune system. We believe it is easier to understand that, whilst a few factors (like radiation) may cause direct damage to your DNA, many factors (like poor diet, toxins, infection) may weaken your immune system and be an indirect cause of cancer. Our understanding of this topic is that if the immune system cannot cope with rogue DNA messages, cancer cells are freer to start their colonisation of your body. Even then they must multiply, taken on blood supplies, fire off around the body, etc.

Real nutrition for the person, or pet, with cancer is important for many reasons, including:

  • The immune system needs bolstering to fight at full strength;
  • The diet may be adjusted to cope with various symptoms, such as constipation, diarrhoea or nausea;
  • Loss of appetite or an increased metabolism means that high-energy foods may need to be included in the daily diet;
  • Extra protein may be needed to help prevent loss of muscle from weight loss.

Pre-, Probiotics and Bacteria

More importantly, you can eat all the best, most nourishing foods in the world but you will derive little, or no benefit, from them if you do not have the right balance of beneficial bacteria in your gut. And this is a critical point to remember when you look at your fur kids. Beneficial bacteria have been found in more than 4000 research studies over the last couple of years to:

  • control about 85 per cent of your immune response;
  • can make vitamins like biotin, folic acid and vitamin K (all essential to the cancer fight);
  • release short chain esters like sodium butyrate from certain food combinations. Such esters stop inflammation, and bad cholesterol, and sodium butyrate kills cancer cells;
  • bind to (chelate with) toxic substances like nitrosamines and oestrogenic compounds plus heavy metals like cadmium and mercury to eliminate them from the body;
  • digest microbes and yeasts ingested with your food; these are organisms that will weaken you.

Most significantly, your gut bacteria seem to get ill first – they lose their overall numbers and diversity. And you cannot get well until they get well.

Our Opinion?

In our minds, prevention is better than cure. It was Hippocrates who first said that All illness begins in the gut. It is therefore no surprise that research is starting link cancer and the state of your gut health. The use of antibiotics as a “first responder” treatment, is ill informed, as antibiotics = anti-life. If anything, it seems that all the collateral available on the internet concur on one topic – sugar is the fuel for cancer. And in terms of diet, carbs are the primary source for sugar. In the end, prevention should be the strategic approach to these horrible diseases.

Also consider introducing pre- & probiotics in your, and your pets diets. As Dr. Anuska Viljoen, BVSc(Hons) VetMFHom MRCVS, phrase it, we need to get rid of the weed, we need to seed or re-seed the correct bacteria, and then we need to feed the bacteria with real food.

Read More: How your gut bacteria may protect you from cancer, Ana Sandoiu (Article).

Articles and Videos:

Dr Nick Thompson: Cancer in Dogs | Does food make a difference?

Video Link:

Thomas Seyfried: Cancer: A Metabolic Disease With Metabolic Solutions

Video Link:

Dr Judy Morgan discuss Cancer and Pet Foods

Video Link:

Dr Karen Becker on Cancer in Pets

Video Link:

Dr. Karen Becker Talks About Osteosarcoma in Dogs

Video Link:

Dr. Karen Becker Mast Cell Tumors in Dogs and Cats

Video Link:

Dr. Karen Becker Discusses Brain Tumors

Video Link:

Dr. Karen Becker Discusses Anal Gland Cancer in Dogs and Cats

Video Link:

Dr. Karen Becker Discusses Bile Duct Cancer in Dogs and Cats

Video Link:

Dr. Karen Becker Discusses Adrenal Gland Cancer in Dogs

Video Link:


  1. Kidd C. The many challenges of veterinary oncology. Can Vet J. 2008;49(11):1132-1135.
  2. Bertram J. The molecular biology of cancer. Mol Aspects Med. 2000;21(6):167-223. doi:10.1016/s0098-2997(00)00007-8
  3. Brand R. Biographical sketch: Otto Heinrich Warburg, PhD, MD. Clin Orthop Relat Res. 2010;468(11):2831-2832. doi:10.1007/s11999-010-1533-z
  4. WARBURG O. On the origin of cancer cells. Science. 1956;123(3191):309-314. doi:10.1126/science.123.3191.309
  5. Seyfried T, Flores R, Poff A, DAgostino D. Cancer as a metabolic disease: implications for novel therapeutics. Carcinogenesis. 2014;35(3):515-527. doi:10.1093/carcin/bgt480
  6. Seyfried T. Cancer as a mitochondrial metabolic disease. Front Cell Dev Biol. 2015;3:43. doi:10.3389/fcell.2015.00043
  7. Baraano K, Hartman A. The ketogenic diet: uses in epilepsy and other neurologic illnesses. Curr Treat Options Neurol. 2008;10(6):410-419. doi:10.1007/s11940-008-0043-8
  8. Paoli A, Rubini A, Volek J, Grimaldi K. Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. Eur J Clin Nutr. 2013;67(8):789-796. doi:10.1038/ejcn.2013.116
  9. Donaldson M. Nutrition and cancer: a review of the evidence for an anti-cancer diet. Nutr J. 2004;3:19. doi:10.1186/1475-2891-3-19
  10. Gibson T, Ferrucci L, Tangrea J, Schatzkin A. Epidemiological and clinical studies of nutrition. Semin Oncol. 2010;37(3):282-296. doi:10.1053/j.seminoncol.2010.05.011
  11. Goralczyk R. Beta-carotene and lung cancer in smokers: review of hypotheses and status of research. Nutr Cancer. 2009;61(6):767-774. doi:10.1080/01635580903285155
  12. Hullar M, Burnett-Hartman A, Lampe J. Gut microbes, diet, and cancer. Cancer Treat Res. 2014;159:377-399. doi:10.1007/978-3-642-38007-5_22
  13. Bultman S. The microbiome and its potential as a cancer preventive intervention. Semin Oncol. 2016;43(1):97-106. doi:10.1053/j.seminoncol.2015.09.001

* Disclaimer: This information is for educational purposes only and is not intended to replace the advice of your own veterinarian or doctor.