Cancer in Dogs

May 16, 2025

Cancer in Dogs


Domestic dogs have never had it better. The best kibble and veterinary care, monthly parasite prevention, annual boosters, all the things we are told to do to preserve their health, yet, unbelievably, dogs are sicker than ever. More pancreatitis, more autoimmune diseases, skin & digestive issues, kidney disease, and, most staggering of all, domestic dogs are ten times more likely to get cancer than humans. 5,300/100,000 pampered pooches in America yearly are diagnosed with cancer compared to just 500/100,000 Americans. Our pampered, adored dogs have never consumed more processed food, have never consumed more pet pharma, yet they are sicker THAN EVER. Something doesn’t add up; it’s time we take a different approach.

High carbohydrate diets are the biggest culprit for most cancers in dry-fed dogs today.
It’s a fact that environmental factors cause more than 90% of cancer; the worst is the wrong food. Diet plays a very significant role in cancer development. Poor quality ultra-processed meats, rancid fats, high salt content (to name but a few) and most of all, too much-refined carbohydrate in ultra-processed canned and kibble food is fueling these shockingly high rates of cancer that we see in dogs today, 9 out of ten of which are fed these biologically inappropriate diets. The following is taken from my book Feeding Dogs (refereneces available on request)

Tumours are total carb/sugar junkies. In fairness, all cells need sugar to operate, but cancer cells use glucose at 10-20 times the rate of normal cells (Bäck 2011, Connealy 2017). Their high sugar uptake is actually the main way we look for them, using a method called a PET-CT (Positron Emission Tomography and Computed Tomography) scan. PET scans use radioactively labelled glucose to detect sugar-hungry tumour cells. When patients drink the sugar water, the mix gets preferentially taken up by the cancer cells, and they light up. This helps physicians see where it is, evaluate the extent of the disease, deduce which treatments to use and check if those treatments are working. In fact, all the way back in 1931, Otto Warburg won the Nobel Prize for his discovery that cancer cells have a different energy metabolism to healthy cells, notably a greater rate of glycolysis (the process of converting glucose to energy) compared with normal cells.

In this way, a high-sugar diet and cancer are the best of friends, but the relationship goes much deeper than that. Macrophage-mediated programmed cell removal (PrCR), or phagocytosis, is essential in tumour surveillance and elimination. These are the seek, engulf and destroy cells of the immune system. We’ve known since 1971 that just 100g of sugar via sucrose, honey or orange juice significantly reduces phagocytosis in humans, and the effect can last up to five hours (Sanchez et al. 1973, Ringsdorf et al. 1976). This is most welcome if you’re a cancer cell thinking of getting up to mischief.

Studies show that reducing carbohydrates prevents dog tumour growth (Ogilvie 1998).

So, with all this in mind, a diet high in ultra-processed kibble and canned food, which is often up to 50% in tumour-loving carbohydrates, will not play any part in preventing your dog from getting cancer and will certainly not help support a dog already battling with the disease.

But wait…. a magical new ultra-processed prescription diet for dogs with cancer hits the market…
With the recent announcement by the AVMA (American Veterinary Medical Association) of a completely new, ultra-processed food for dogs with cancer by Hills - Onc Care, many people rushed with eager anticipation online to find out what medicinal and wonderful properties this prescription cancer diet surely must contain and all the studies to back up their claims… there were no studies available…

These are just a few of the ingredients:

Chicken - well, that’s a start… Just a shame that it is heated at extremely high temperatures several times, chemically preserved, then sprayed with rancid fats, high levels of salt, etc, and then pushed through an extruder to give it the little round kibble shape. Not to mention that the chicken that ends up at the rendering plant, where ultra-processed pet food is made, will not be nice cuts of fresh muscle meat. It will be the parts that the butcher cannot sell to humans.


Whole grain wheat - refined carbohydrate… the second ingredient in a food for pets with cancer….


Corn gluten meal - This is often added to pet foods to raise the protein level. Corn gluten is a source of protein; however, this type of protein is not bioavailable and completely indigestible for our dogs, fueling inflammation - the enemy of cancer.


Additions such as fish oil and coconut oil - these ingredients are fantastic… in their fresh form. Fish oil heated several times at high temperatures and left to sit in a bag on a shelf for months will not even come close to the huge benefits of feeding your sick dog some fresh sprats full of much-needed omega-3 fatty acids. Once those fats are rancid, they will make your dog more inflamed and sicker.
Carrots and cranberries - again, fantastic in their fresh form, although starchy vegetables such a carrots aren’t the ideal vegetable for a dog who needs to avoid carbohydrates. Again, not sure how much benefit any of these will be when they are pulverised and cooked at high temperatures.

Ground pecan shells - Not sure what to even say here. I can think of absolutely no reason why ground pecan shells would be added to any dog food, let alone one for cancer. Adding the actual pecans, you could argue, would be adding some good fats, some vitamin e etc but the shells…?

Not only is this food, and most ultra-processed foods, full of tumour-loving refined carbohydrates, but most of the ingredients are also indigestible (you try digesting a ground pecan shell!); the worst possible diet for an animal who is sick, who’s body is already inflamed, they need wholesome, fresh, species appropriate food to enjoy and, most of all, full of natural vitamins and minerals to nourish and heal their bodies.

My dog has cancer; what can I do?
If your dog has cancer and you’ve been to the vet, you must consider the following:

Feed a fresh diet
This now need to be higher in fat, moderate protein and virtually zero carbs. That means a fresh meat, organ and bone diet. Remove all sources of sugar, including rice and starch-rich vegetables such as peas, carrots and potatoes. Feed them like a carnivore as this will starve tumour growth.

The usual 70:10:10:10 ratio will still be good (meaning lots of meat, 10% bone, 10% organ, and some green leafy plant matter for their bioactive compounds). However, you want to consider their diet consisting more of higher-fat red meats such as beef, pork, duck, oily fish, and maybe lamb, depending on the pieces used. You could also add some eggs and mussels.

Now really is the time to think about the quality of the meat. Organic, high welfare, pasture/outdoor reared meat is a must. Studies show intensively reared meat, particularly chicken, is inflammatory to dogs, this US study shows a mix of antibiotics used, that reside in the bones of the bird and the high omega 6 content of the meat from the grain diet.

Organic, outdoor-reared meat contains much more omega 3 and these fatty acids are vital for dogs with cancer as they help to reduce chronic inflammation. We now need to fight inflammation by keeping the amount of omega 3 up (and 6 down) in our diet. Omega 6 comes from vegetable oils so we now avoid these in cancer dogs. However, there are some other oils that are good here - something like coconut oil is fine, lower in omega 6 and full of fantastic MCT (medium chain triglycerides).

Remove any pet store treats that contain cereal/dairy/sugar or anything that has been chemically preserved.

Cut out the unnecessary chemicals
Chemical flea and worm treatments and all boosters have been linked to cancer in dogs. Move to the many natural treatments available and stop piling on chemicals for parasites that your dog does not have.

Think about the chemicals you use inside your home, scented candles, air fresheners, and all of that anti-life cleaner you wash your floors with and that your dog lays on every day. Now's the time to jump to probiotic floor cleaners. I recommend Ingenious Probiotics in the UK for a list of these sorts of info and products. Great company.

Supplements

Good quality seaweed.
Seaweed has some unbelievable anti-cancer properties. Here are 13 independent studies that show seaweeds fight cancer growth. We picked four of the main seaweeds used in these studies and put them in a highly popular product we call AC4. You must be very careful making any claims about cancer; we can only hope it will help.

Vitamin E
This will be needed now that the dog is on a higher-fat diet. Recommend 500IU for small dogs, 1000IU for medium dogs, 1500IU for large dogs..

Golden Turmeric Paste
Make golden turmeric paste for dogs. Turmeric is one of the most famous natural anti-inflammatories. It has a long history of fighting cancer. Studies show it can contribute to the death of cancerous cells, reduce angiogenesis (growth of new blood vessels in tumours) and reduce metastasis (spread of cancer). We recommend 1/3 of a tsp per 10kg of dog per day. Be careful with GTP; there is a drug clash here with blood thinners and some anti-inflammatories from your vet.

Omega 3
Omega 3 fatty acids are vital for boosting the immune system and reducing chronic inflammation that leads to cancer. As always, nutrients in their whole, raw form are superior to the isolated, treated, mass-produced variety available in pill form. In this way, a little fresh oily fish is the first place you should go. They don’t need a lot; as little as 100g a week for a 15kg dog would be fine.

Medicinal mushrooms
Now and then, there is an explosion of new “superfoods” that everyone is talking about, and medicinal mushrooms are getting lots of attention at present. And so they should be. The health benefits of eating mushrooms are astounding, and medicinal mushrooms are cancer-fighting machines. They owe their superpowers to unique polysaccharides called Beta Glucans. Beta Glucans help to activate immune cells, which will trigger an immune response in the body, so when we are talking about cancer, this response sends in the troops, and they attack the cancer cells and also help slow down their growth.
Here are just a few of the top mushrooms for cancer:

Maitake
Studies show that the bioactive extract D Fraction, which is found in this mushroom, had a huge effect on cancer cells, and when it came to lymphoma cells, the study found that 90% of the cells were dead in 24 hours!

Turkey tail
This powerful mushroom can not only help to restore immune health, but the two types of beta-glucans - Polysaccharide P (PSP) and Polysaccharide K (PSK) in turkey tail can actually increase immune cell activity by causing immune changes. A double-blind, randomised study in canine hemangiosarcoma, deadly cancer in dogs that metastasises quickly, showed that just administering PSP to these dogs significantly delayed the progression of metastases. The researchers also recorded the longest survival times reported in dogs with this disease.

Reishi
The most popular mushroom used in Traditional Chinese Medicine, the reishi mushroom is an extremely powerful immune booster, good for supporting the liver and the polysaccharides trigger white blood cells in the immune system called lymphocytes which provides anti-tumour support. Studies have shown that reishi mushrooms have anti inflammatory and anti cancer properties to breast cancer and melanoma in particular. Interestingly, reishi and shitake mushrooms work in synergy with one another so are much more potent when taken together.

We could go on and on about the power of different mushrooms, as there are so many more to discuss, such as lions mane, chaga etc, but we will let you do your own research there, fascinating stuff. As you can see, adding mushrooms to the diet could have a enormous, positive impact on your dog with cancer. Many companies sell these in capsule or powder form, use 1/2 tsp per 10kg of dog per day, more initially.

Other stuff to note…

Clean those teeth:
Dirty teeth are highly inflammatory. Animals with tartar and gum disease are shown to suffer more diseases. Raw meaty bones clean teeth best, natures toothbrush. If the tumour is in the mouth and he can't chew bones, I recommend our product Dr Brady's Dental Pro Clean for cleaning teeth. It's highly effective (but can't be used WITH AC4. Stop the latter until the teeth are clean; Dental Pro Clean will do a little of what AC4 does in the meantime).

Filter drinking water
Ensure your dog's water is not full of chlorine and other nasties straight from the tap - We need to take care of that gut flora more than ever, so filtered water is a must. If you do not have a water filter, boil tap water and leave it to chill.

Ensure your dog is not overweight.
Now is the time to get your dog lean. Excess fat drives inflammation in the body. Once you move away from a high-carb diet, that weight will fall quickly. Dogs are meant to be super lean; they are long-distance runners. Studies in humans show that being lean is vital for longevity.

In conclusion…
As you can see, a fresh, species appropriate, natural approach is vital in preventing cancer and is essential to aid in their recovery should they get sick. Please ensure you are working alongside your vet and discuss any concerns and diet with them - preferably, you would want to work with a vet that has studied nutrition and is not advising high carbohydrate ultra-processed food (or ground pecan shells?!). The times we live in, seems to be it’s either conventional or its dark arts - however, both can, and do work in synergy together. So lets work with both conventional when needed and the most natural approach to ensure that our dogs can concentrate on being dogs; living the carefree, healthy, long lives they deserve.

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