Skip to main content

Certain pet food could put a strain on a cancer patient


When our dog has cancer, his body has enough to deal with without fighting off the effects of toxic substances from his food. We want to make sure, especially while our pet is being treated against cancer, that his food is not going to further contribute to cancer, or weaken his health. Nevertheless, it is important to mention that cancer researchers do not fully understand the mechanism the nutritional influences on cancer – yet.

Human food ingredients have lower thresholds for certain toxic substances than dog food ingredients. As a matter of fact, certain studies have shown that there are toxins found in pet food which can irritate the intestines, suppress the immune system, and even be carcinogenic (causing cancer). Although not every exposure to carcinogens causes cancer, every exposure increases the risk of developing or aggravating cancer.

Examples of toxins which might be found in industrial dry dog food:

  • A different types of mycotoxin, a poisonous chemical compound produced by certain grains and seeds, the main ingredient of animal food

  • B Nitrites and Nitrates: preservatives that are found in many processed and smoked meats and also in many brands of dog food. Will be listed on the dog food label. Although these preservatives do a great job of extending the shelf life of the food, they are not so good for you, or for your dog, when they’re in the body. Nitrites and Nitrates are not carcinogens in themselves. However, when the body digests them they are converted to cancer-causing chemicals by the digestive process. For this reason, I do not recommend feeding your dog any food that contains nitrites or nitrates. This includes commercial dog foods, of course, but it also includes many human foods like hot dogs and sausages.

  • C Ethoxyquin: can be found in “Fish Meal” (as listed on the dog food label) and has been shown to cause kidney damage

  • D Heterocyclic amines: The result of high temperature processing of foods: to increase shelf stability in dry dog foods, a mixture of meat (animal remains) or fish, fat, grains or potatoes is heated to a very high temperature and pushed through a machine called an extruder to form kibble. These high temperatures produce chemicals called heterocyclic amines, which are known to be extremely potent carcinogens.

  • E Acrylamide: Another carcinogen produced by applying high heat to food – especially starchy food like corn.


We dog owners are usually very dependent on processed, non-perishable, commercially available pet foods, primarily kibble, which isn’t really the ideal nutrition in the long term for any pet.

In fact, more and more dog owners and pet nutritionists are dubious about the current state of most available industrial pet food. This becomes all the more dubious with the concept of food ingredients that are accepted as safe for animals, but judged unsuitable to be fed to humans.

Whole-food feeding might be the key. 
→ Wikipedia Mycotoxin
→ the Dog cancer diet (PDF)

Der Jahrtausendirrtum der Veterinärmedizin by Klaus Dieter Kammerer
Published in Germain in 2013, by exsuscitati
→ Der Jahrtausendirrtum der Veterinärmedizin

Can a special diet prevent canine cancer?


Just as in human cancer, there is no special diet or superfood that can prevent cancer in dogs. However, some studies do show the benefits of different vegetables and herbal supplements in improving the overall health of a pet, both those with and without cancer. For example, University of Pennsylvania School of Veterinary Medicine treated dogs diagnosed with hemangiosarcoma with the Yunzhi mushroom, also known as the Coriolus versicolor mushroom. The results were promising, with the dogs treated with the mushroom having the longest survival times compared to other treatment studies conducted by the school. It should be noted that this is only one study and that more trials are underway. Furthermore, all dogs in this trial had already been diagnosed with cancer.

No definitive studies prove that a certain diet or supplement will prevent cancer. For more information about various pet supplements, check out the article written by the Animal Medical Center of New York.

→ Get the Facts: 7 Pet Cancer Myths Debunked


Whole-food diet plan for cancer patients


It’s simple to make dietary changes to a whole-food based diet that can really benefit the health and strengthen the immune system of your dog, especially during cancer treatment, when the overall condition of the dog is generally weakened.

Be aware: Any diet plan must be calculated for every individual dog and its individual state by an experienced nutritionist! 

A new diet plan was recommended and tailor-made for Alice during her treatment, to ease her digestion and strengthen her immune system. The diet was calculated by the University of Zurich Institute of Animal Nutrition, Switzerland especially for Alice’s state of health, age, energy needs and weight.

When changing the diet plan of your dog, it is important to regularly supervise his weight and general condition. Should the dog put on or lose weight, the nutrition plan has to be adapted accordingly. If your dog has problems with the rations, if for example he doesn’t want to eat or starts vomiting, please contact your specialist nutritionist sooner than later. The diet plan must then be adjusted to your dog’s needs.

The new nutrition plan for Alice during her cancer treatment was carefully calculated to cover all the nutrients she needed. In addition, it had a low carbohydrate content, since human studies have shown that the preferred energy source of some tumor cells is carbohydrates. She received a high portion of carrots, which contain a lot of vitamin A. I was asked to cook the meat and vegetables well during the chemo, as cooked food is less stressful for the gastrointestinal and immune systems. I had to give Omega 3 capsules (fish-oil capsules) and linseed-oil on a daily basis to provide Alice with essential fatty acids, which are also anti-inflammatory. According to the recommendations, Alice’s new diet plan had to be supplemented with eggshell powder (calcium) and trace elements (Kynovit BARF) and vitamin D (pharmacy). Moreover, Alice also received a B vitamin supplement from the pharmacy.

As mentioned before, I was asked to boil meat and vegetables well, in only a little water, and to feed her the cooking water too, since all the vitamins are dissolved in the water after cooking. ATTENTION: This does not apply to potatoes, as the cooking water contains a substance which is toxic for dogs.

However, during chemotherapy, one should not give too many antioxidants, because you want the chemotherapy to produce free radicals, which then attack the tumor cells.

If your dog isn’t able to eat anymore, alternative feeding methods like feeding tubes might be required. 

You might also want to inquire about appetite stimulants and other medications that can reduce side effects, especially if other medications are causing a loss of your pet's appetite. 

Ernährungsberatung des Institut für Tierernährung
Vetsuisse Fakultät Universität Zürich
Winterthurerstrasse 270
8057 Zürich 

 For dietplan recommendation and calculation by the Institute (also in English):
 Download questionnaire by the Institute

Der Jahrtausendirrtum der Veterinärmedizin by Klaus Dieter Kammerer
Published in Germain in 2013, by exsuscitati
→ Der Jahrtausendirrtum der Veterinärmedizin

What we can learn for our dogs from anticancer diets for humans


As we have learnt in chapter 3, about the close collaboration between human and veterinary cancer research, dogs have greater than 80% genetic similarity to humans, according to the American Animal Hospital Association (AAHA). In fact, some types of canine cancer are identical to cancer in people and thus respond to the same treatments.

Could we deduce from these findings that the same food products have the same benefits in both humans and dogs? It is reasonable to think that a treatment which has been shown to help humans could also help dogs. So let’s have a look at the following recommendations for human cancer patients. Perhaps we could get some inspiration from them!

Pink Ribbon Foundation


→ (see the end of this chapter) recommends on their homepage an anticancer diet which is principally composed of vegetables and fruits, accompanied by olive, canola, or flaxseed oil, organic butter, garlic, herbs and spices. Meat or eggs are also optional. The following image depicts the classical “anticancer plate“, recommended by many nutritionists.

read more about


Diet and Lifestyle


Heather Smith lives in Ayr (Scotland) with her 4 dogs of different breeds.
She is an internationally reknown and successful canine sport's veteran in obedience, agility, Heelwork to Music and Canine Freestyle. She is a sought-after dog trainer, canine sport judge and seminarist with a lifelong experience with dogs.
Heather has been involved with breeding and dog-shows as well.


My thanks to Yvonne for creating this website, canine cancer as with human cancers seem to be more prevalent so I am sure this will provide a resource for so many who will echo my thanks.

I feel privileged to be asked to share my personal account of how I feed my dogs, and in doing so share my belief that a high quality raw and natural diet can keep a dog healthy as well as add to the enrichment of the dog’s life.

Sometimes it takes something to happen to our dogs before we look at what we are doing and how we are feeding them. This happened to me! One of my Bearded Collies, Polly was diagnosed with struvite crystals in her urine and she wouldn’t eat the special diets that we were prescribed by the vet, I was so concerned, as she was already very thin and ate very poorly at the best of times. I took advice from a natural feeder who suggested I changed her urines alkaline PH to acidic through feeding her meat especially red meat and whilst doing so hydrate her by not feeding dried kibble. I took the advice with trepidation as this was about 25 years ago and raw feeding wasn’t so fashionable however she never looked back and she lived until she was 16 years old without any ill health until her final week in life.

At the time I did think back to how my parents’ dogs were fed in the days prior to dried food, and raw meat was the order of the day. This was a turning point for how I fed my dogs and I did a lot of research before forming the conclusion that dried food is a convenience processed food and is the fast food of the dog world, just as bad for our dogs as human varieties of fast food are for us. Since Polly there have been other long lived dogs and I’ve had golden oldies that have lived long active lives to 16, 17 and 18 years old recently. I have now lived with two dogs that were weaned onto a raw diet by the breeder, Bonnie lived to sixteen years old and fought back from a stroke not even our vet thought she’d survive to live an additional two normal years and I currently have a rudely healthy Gertie at seven years old! Since Bonnie I have often thought that perhaps the varied diet is part of the varied lifestyle that gives my dogs something to live for.

So what do I feed my dogs? I guess I am a raw feeder though that term covers a wide variety of styles of feeding.   There are so many books to help you on your way and I started by reading Ian Billinghurst and Tom Lonsdale which give excellent advice and since then have found my own way to some extent.

My starting point is to feed human quality food and where possible both Organic and free range. We are what we eat and this should be good quality. I am sceptical of the quality of some commercial raw dog meats which are not fit for human consumption. If it’s not good enough for me then my dogs deserve better!

There are two meals a day for all my dogs by the time they are adult and a supply of treats throughout the day.

The main meal of the day is dinner in the evening which consists of meat, bone as well as fruit/vegetables and herbs. The meat and bone make up most of the meal approximately 75% and the remainder is the non-meat part.

These meals consist of a variety of raw fish and meats. I feed fish at least twice a week though I have been supplementing daily with fish oils all my life, initially with cod liver oil as my mother always did! They enjoy a range of meat types such as lamb ribs, oxtail, poultry such as chicken, duck, turkey on the bone and of course they do enjoy minces from pork, beef, lamb etc. I feed offal usually in the form of liver or tripe once a week too. The kind of fish also varies with salmon being an especial favourite. I use a lot of tinned fish such as mackerel, pilchards and sardines which are also very easy to use when travelling.

The dogs enjoy a bone source every day as part of dinner, but they also have recreational bones which are accessible all the time where they can chew by choice and this is the most popular activity at home. Bones act like toothbrushes for dogs keeping their teeth clean as well as forming a source of minerals, protein, fatty acids, Vitamins A, D and E nutrients such as copper and iron from marrow and fat and protein of course. My dogs all have great teeth right into old age!

Perhaps it’s because I am a vegetarian that I make such a deal about the fruit, vegetables and herbs aspect of my dog’s dinner. Dr Ian Billinghurst says this is an important aspect of a dog’s diet especially in relation to cancer and kidney disease. As such this has to be vitally important and I make vegetable and fruit mixes for my dogs to reflect this. These are pulped in my food processor for better and more natural absorption in my dog’s diets, and they can easily be prepared in advance and stored in ice cube trays in the freezer. I use vegetables and fruit that I eat and as such the variety they get is wide. There are a few fruits and vegetables that you can’t feed to your dogs such as onions and grapes and some that are not so suited to older dogs where I avoid tomatoes or any acidic fruit for them. In the summer my dogs like the strawberries and raspberries from the garden and have been known to steal them and in the autumn they eat the brambles from the bushes on walks and my little rescue eats the fallen apples from the trees. I do believe dogs know what is good for them!

Let’s not forget herbs which can be such a positive force in our diet. The herbs I grow are not just for me but for my dogs to share and I regularly add parsley, basil, oregano, rosemary, peppermint to the vegetable mixes. Herbs help the body’s immune system by acting as antioxidants; they help with cognitive ability in old age as well as play a role in cancer prevention as well as support immune function. I use both fresh and dry herbs and regularly add to both our veggie mixes as well as add separately where a particular dog may need something extra. My favourite antioxidant mix which includes watercress, peas, celery, spinach as well as parsley is an especial favourite. More than a few of my dogs choose to eat the herbs from those I grow at their level with antioxidant parsley and calcium filled basil being particular favourites with all. Recently through the spring and summer months I have been adding Oregano for ticks prevention which seems to be very effective as I have only removed two ticks all year!

Let’s not forget about breakfast even though it’s a small meal. Through the winter months this frequently is shared with me and includes porridge with berries, on other days they also enjoy a raw egg or perhaps two if it is little quail eggs and they have the fun of the shell removal, cottage cheese topped with sardines or flax seed oil is also popular and yogurt with blended fruit which in the summer I freeze for them is always appreciated.

Of course I do take into consideration the individual needs of each dog so for example my older dogs do not get pork especially if they have a touch of arthritis and I add bone broth (made of 80% bone and meat to 20% vegetables) to their diet most days of the week.

There are also titbits and treats to consider and there is an array of natural treats available these days. My dogs enjoy fermented Yak Milk chews and alternative rawhide chews but the reality is they enjoy a bone far better. For training I do dehydrate meat but also they get to have cheese, cooked meats, pate and a variety of homemade baked goodies from kipper cake to good old liver cake! When baking I do avoid wheat flour and use oats and rice flour in preference.

Treats are part of our lives and of course as I write this I am aware I have bought Dog Safe chocolate treats so the girls can have some chocolate when I have mine over Christmas. And they do enjoy table scraps if they are safe for them to have as well as a lick of the honey spoon or a piece of toast.

Raw feeding offers our dogs such variety in their diet that this surely has an impact on their wellbeing not only in terms of health but there enjoyment of life generally. We are all so aware of enriching our dog’s lives in other ways such as varying where we walk, teaching new things, and providing outlets for our dog’s natural instincts such as scent work. Now Imagine a life spent eating only kibble – not very enriching!

Heather Smith