No! The answer is in the evolution of cats and dogs and the divergence of their “evolutionary paths” some 30 million years ago.

Both are scientifically classified within the class Mammalia and within the order Carnivora. The divergence in evolution resulted in dogs becoming members of the Canoidea superfamily and cats becoming members of the Feloidea superfamily1.


Photo: Igmur


The Canoidea includes species “with very diverse dietary habits”1 while Feloidea includes species that have evolved as “strict carnivores”.

There would seem to be some debate as to whether the dog is carnivorous. Incidentally species in the order Carnivora are not necessarily carnivorous. “Most species of Carnivora are, to some degree, omnivorous, except the Felidae (cats)”2.

Linda P Case in her book1 says that dogs are omnivorous while other authors say that they are carnivorous3. Dogs are said to be adaptable carnivores4.

It probably doesn’t matter. What matters is that the cat is a strict or obligate carnivore while the dog is more flexible.

The ancestors to the domestic cat, the African wildcat and the European wildcat both feed entirely on small animals such rodents.

The cat has stuck to the strictly carnivorous diet even in domestication (perhaps, however, in 1000 or more years time the domestic cat will be less strict about what it needs to eat?). This has resulted in specific physiological and metabolic adaptations. In other words the cat’s digestive tract and chemistry has evolved to accept animal tissue and almost nothing else. There are minor exceptions. Cats do eat grass and one big cat, the snow leopard deliberately eats vegetation to enhance its absorption of oxygen as it lives at high altitude.

The cat then has “peculiarities in nutritional requirements”1 while the dog is very adaptable and can survive on an omnivorous diet. The cat cannot survive on an omnivorous diet.

The cat’s dietary requirements are more stringent than that of the dog. The cat has a high protein requirement – too high for the dog on a long term basis. It has a need for taurine, arginine, arachidoonic acid and preformed vitamin A, for instance. See also Taurine Deficiency in Cats. Or how rice in cat food can affect taurine. Do Bengal cats need more taurine?

For a domestic cat, a diet without animal tissue would require supplementary additives to add in the required nutrients.

A dog eating cat food would find it too rich it is said and it might cause diarrhoea and obesity. One commentator said that a dog on a long term cat food diet might lose its eyesight5. I don’t know if this is true.

Dogs like the taste of cat food because it is rich in protein (higher protein content than dog food5) but can dogs eat cat food? Yes in small doses and occasionally but NO as a long term diet.

Associated page:

Raw Food Diet – Homemade Cat Food

Can Dogs Eat Cat Food? – Notes:

1. The Cat, Its Behavior, Nutrition & Health by Linda P Case.

2. http://en.wikipedia.org/wiki/Carnivora

3. http://en.wikipedia.org/wiki/Carnivore

4. http://www.rawfed.com/myths/omnivores.html

5. http://answers.yahoo.com/question/index?qid=20060916061208AAJUFBB

From Can Dogs Eat Cat Food? to Best Cat Food

Comments for
Can Dogs Eat Cat Food?

Click here to add your own comments

Dogs should NEVER eat catfood
by: Anonymous

Purina One is a Great dog food. I feed my dog purina One with oatmeal and natural blends..Look at the recall list of pet foods…Purina is NOT listed.BUT, I also Cook for my dog…boiled chicken, rice,green beans, and carrots…so she does not eat JUST dog food.I would not recommend any dog to eat catfood…ever! From experience! It causes diarhea, kidney problems,etc.in dogsw.


Food for both Cats and Dogs
by: Andrew @ WestCoastPetSupply.com

There are food formulas that work great for both cats and dogs. An example is Wysong, they have several great dry and canned formulas that are designed for both Cats and Dogs!


on food
by: Kathy W

After reading on this page that Purina does animal testing i was quite upset since purina was our cats main diet. Not only the dry food but the canned as well was also made by Purina. Friskies and Fancy Feast. I have not found out the extent of their animal testing but we are in the process of weaning our cats off of the Purina Dry which they love. I have been feeding Lia their Pro Plan for senior cats 11 and older and hes doing very well on it. He has so much extra energy and seems very happy. He doesnt seem so lethargic like he was before. We have switched back to the Blue Buffalo brand of Wilderness, We also are going to add Wellness as their main course. We however are stumped on the canned since they hate Friskies. I tried some other cans over the weekend and Lia knew immidiatly it wasnt fancy feast.


on food
by: Kathy W

After reading on this page that Purina does animal testing i was quite upset since purina was our cats main diet. Not only the dry food but the canned as well was also made by Purina. Friskies and Fancy Feast. I have not found out the extent of their animal testing but we are in the process of weaning our cats off of the Purina Dry which they love. I have been feeding Lia their Pro Plan for senior cats 11 and older and hes doing very well on it. He has so much extra energy and seems very happy. He doesnt seem so lethargic like he was before. We have switched back to the Blue Buffalo brand of Wilderness, We also are going to add Wellness as their main course. We however are stumped on the canned since they hate Friskies. I tried some other cans over the weekend and Lia knew immidiatly it wasnt fancy feast.


Please comment here using either Facebook or WordPress (when available).
Michael Broad

Hi, I'm a 71-year-old retired solicitor (attorney in the US). Before qualifying I worked in many jobs including professional photography. I have a girlfriend, Michelle. I love nature, cats and all animals. I am concerned about their welfare.

View Comments

  • I have only known one dog who was fed exclusively on commercial cat food. She was fed it from the age of about two years to about five years. Her human was misguided and because the dog wolfed the cat food down, her human thought it meant that cat food was good for her.

    This dog's skin was constantly inflamed and rashy, her kidneys were a mess.

    The human fell, broke a hip, dog hid under the sofa, stricken with shock at the separation. The human went into a care home on recovery.

    It took Mum three days to coax this little dog out. Her skin cleared up in six months on a decent diet and the kidney damage was slowed right down with some skilful veterinary care.

    Persuading the dog to eat dog food was an endeavour and a half initially. She lived until she was fourteen.

    Sadly her original human developed a rapid dementia not long after entering care, and gradually stopped recognising her dog when Mum took the dog to visit her.

Recent Posts

The Queen of England evicts two cats from Royal Apartment

COMMENT: The story is not what it looks like in the title. But it is…

15 hours ago

20 Sphynx cats rescued

NEAR EDMONTON, ALBERTA, CANADA - NEWS (COMMENT): CTV NEWS (and this story is unique) reports…

18 hours ago

Are Sphynx cats hypoallergenic?

No, Sphynx cats are not hypoallergenic. Sphynx cats are like any other domestic cat in…

19 hours ago

Being curmudgeonly at Thanksgiving 2020

Americans deserve a bit of fun. We all do. It's a time for optimism and…

20 hours ago

Candle sets alight cat’s tail while playing with family dog

A cat is innocently playing with the family dog. Everything is perfect except the cat…

1 day ago

What is eumelanin in cats?

Eumelanin is a pigment in domestic cats and other animals (and humans). It is often…

1 day ago