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Sure they can - if they are forced to, but the more important question is – Should they?!

In the current state of affairs in our society there is ever increasing trend to blatantly ignore basic facts of nature  in order to fit different forms of misguided agendas.  This trend is often justified by so called scientific research. However a deeper look into scientific methods employed to justify these agendas inevitably reveals some fundamental flaws.


Dr. Connor Brady succinctly puts it:

Most canine nutritionists agree the dog is, to a very large extent, a meat, organ and bone eater. An adaptabe, opportunistic, scavenging predator. A whole-animal eater. A carcass-finding machine. A long-distance-hunting machine. Our article on why dogs need meat goes through all the evidence that supports this stance:

From tooth to tail, the dog has the anatomy of a meat eater, with jagged teeth, short, fast, acidic guts, bacterial flora ill-equipped to break down plant fibre breakdown
Studies of their closest relatives (Dingo’s, which were domestic dogs only 3,000 years ago) reveals a diet comprising of 97% animal matter
Stuides show dogs will eat literally anything with a face, from small mammals to birds to frogs to insects to carcass and faeces, though they are no longer able to bring down large quarry
There is confusion in the diet studies as village dogs are fed plant material as pups and these dogs will go on to select plant material when older, however feral dogs do not. We have know for years that dogs can be targetted on to various proteins from a young age, it says nothing of it’s suitabilty to long term health.

Dogs are classified as facultative carnivores, being a highly adaptive and successful species they will forage for plant based food during  difficult times,  however that does not make them omnivores.  This is a scientific fact.
Admittedly, dogs indeed seem to have developed some omnivorous traits.  In  2013, a study found that dogs have 32 more copies of a gene that is crucial for amylase production compared to wolves. The gene is  7-12 times more active in the pancreas of kibble-fed dogs than in wolves. While this study is often quoted by proponents of omnivorous dogs , it is obvious that this represents a miniscule evolutionary step that has developed in the  last few thousands of years and still does not significantly affect dogs’ dietary preference. Fleming et al.2001 gathered an impressive and unprecedented 13,000 stomach samples of largely dingo hybrids and feral domestic dogs over 30 years, spanning six different climatic regions of the Australian continent. To date it is the largest dietary study of any canid. The results were pretty clear, they found animal protein made up 97% of their diet while vegetable matter made up just 3% of content in those samples. Based on their findings Fleming et al. (2001) classified Australian feral dogs, a group consisting mainly of domestic dogs and dingo-cross hybrids, as specialist carnivores.

 Dogs also have the ability to convert carotene  to Vitamin A, some tryptophan to niacin (vitamin B3), as well as cysteine to taurine.  These are clearly quirks in their metabolism that fit their more scavenging lifestyle  and it is very sad to see that such little quirks are eagerly sized upon both by pet food industry to justify ultra high plant carbohydrate content in their products,  and by vegan proponents to convince us that dogs can thrive on a plant based diet.

Jean Dodds (2015) gives us an excellent example to explain how wrong this thinking is:

To say that because dogs can digest some starch better than wolf  proves that they can thrive on a high starch diet is the same as saying that because humans  can process ethanol and glucose, they should thrive on a diet rich in rum and cookies!


When it comes to cats, be it large cats or our domestic small cats, and all other feline species in between, things are even more straight forward. Cats are obligate (strict) carnivores. What does it mean to be an ‘obligate carnivore’?  It means that your cat was built by Mother Nature to get all nutritional needs met by the consumption of a large amount of animal-based proteins (meat/organs) and derives much less nutritional support from plant-based proteins (grains/vegetables). It means that cats lack specific metabolic (enzymatic) pathways and cannot utilize plant proteins as efficiently as animal proteins. Cats don’t even have receptors for sweet taste on their tongues.  Therefore, It is  no wonder that most domestic cats fed on commercial diets rich in grains and starches  develop diabetes or other serious metabolic disorders by the age of 10.


One day a client walked into my practice proudly declaring that she has switched her dog to vegan diet, supposedly she has “investigated the science” and found work by Dr Knight which assured her that dogs and cats can be healthy on vegan diets.

Fortunately, there aren’t many veterinary professionals out there who would recommend vegan pet food with a clear conscience, and I was keen to discover who this Dr Knight is.  And there it was, a whole online vegan pets’ community, consisting mostly of  commercial vegan pet food producers and almost all of them cite “scientific research” by Dr Andrew Knight, a kind vet who seems to have become  somewhat of a guru of pet veganism.

According to his website, Dr Knigt  is currently a veterinary Professor of Animal Welfare at the School of Environment and Science at Griffith university in Queensland. This is ironic if we consider that failure to provide animals with appropriate care and biologically appropriate nutrition amounts to animal abuse.

It is also a bit like encountering a bonsai tree expert trying to convince us that trees in his care can thrive without getting nutrients from the soil substrate.  The world we live in seems to be getting crazier by the minute.  

Nevertheless, I was curious to read all of Knight’s research and was disappointed to find out that there is not a single peer reviewed paper or randomized controlled trial about the effect of vegan diet on carnivorous animals like dogs and cats. 

Instead, there is a whole list of articles he published in various  magazines, most of them based mostly on theorising, data stretching and lots of presumptions.  

The most seminal work of  Dr Knight ( at least in the vegan pet community) seems to be Vegan versus meat – based dog food: Health outcomes.

This is a whopping 32 pages online survey of dogs fed vegan food that does seem very elaborate to an average inquiring owner untrained in reading scientific literature. However, it is nothing but a survey of a large sample of dog population with data relying on the subjective reports provided by the guardians. Even Knight et al admit:

“Additionally, our study relied on both quantitative information and opinions provided by guardians.  The most reliable medical studies are large scale, prospective studies that utilise relatively objective assessments of unambiguous data.  Veterinary clinical examinations and veterinary assessments of animal health status, would normally be more reliable than guardian opinions alone…”

Dude – in science it is all about the control group – to whom you are comparing your results?

Unfortunately, no real science here, just assumptions, presumptions, and more assumptions.

Naturally, like all proponents of vegan dogs, Knight is calling upon the famous Brown study. This was a small study of sled dogs.  Knight interprets it as: “there was no difference in performance between vegan and meat fed dogs” however what this study REALLY tells us is that one group of dogs was fed cereal based kibble with the addition of some  by-products from the meat industry, while the other group was fed plant-based kibble. Both groups performed equally well. Well Sherlock, no surprise there.

Other scientific publications of Dr Knight include:

Transition to plant based diets will help us fight pandemics , a tale which starts with bats as a large reservoir of SARS-CoV- like viruses, Influenza risks from pig and poultry farms, as well as Looking Harder at Mad Cow Risks, Climate change: Livestock population to name just a few.

Knight  is also lobbying hard  to  change the British Veterinary Association official stance that cats are obligate carnivores and that dogs need meat in  their diet. In other words he is  trying to fit a round peg in square hole.  Good luck with that.


Yes, many of them do. However, there is a very big difference between surviving and thriving in a vibrant state of health.  Veterinary practitioners are now witnessing epidemics of obesity, metabolic disorders, cancer and inflammatory and degenerative disease in domestic pets. What most proponents of vegan foods for pets fail to understand is that nutritional deficiencies take years, if not decades and multiple generations, to create grave illness’ and by then it is already too late. I urge you to not experiment with your pet’s health and life.

I will leave you with several British Veterinary Association statements:

“Meat contains vital vitamins and nutrients needed by cats and dogs. Although we would not recommend it, it is theoretically possible to feed a dog a vegetarian diet, but owners would need to take expert advice to avoid dietary deficiencies and associated disease, as it is much easier to get the balance of nutrients wrong than to get it right. A dog on a vegan diet may also need synthetic supplementation. »

“Cats are obligate carnivores and should not be fed a vegetarian or vegan diet as they require animal-sourced ingredients to provide essential nutrients, such as taurine and preformed vitamin A, which are minimal or even absent in plant ingredients.”

“While on paper a vegan diet for cats may include supplements or alternatives to animal-based protein, for example, there is no guarantee that these would be bioavailable to the cat or that they wouldn’t interfere with the action of other nutrients. That is why robust, peer-reviewed research is needed to ensure that non-animal protein sources can meet the pet’s dietary requirements.

Under the UK’s animal welfare acts, pet owners have a duty of care towards their pet to ensure that their five welfare needs, including an appropriate diet, are met. Owners could potentially be prosecuted under the provisions laid out by this Act for causing deliberate harm and suffering to any animal by failing to meet its welfare needs despite expert advice.”

For anyone who wishes to learn more about the real science behind dog nutrition, I wholeheartedly recommend Dr. Conor Brady’s book: Feeding Dogs it is jampacked with references to actual scientific research for every single one of its assertions.




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