Is Dog Food Toxic To Cats?

Is dog food toxic to cats?

No, it is not toxic – but dog food lacks essential nutrients that cats absolutely require.

While a cat can (and often will) eat dog food, that food is 99.9% certain to be lacking in some of the vital things that cats need to be eating.

A one-off or occasional indulgence of dog food (and anyone who has both animals know how they love to raid each other’s bowls) by a cat is not “toxic” or at risk of causing them long term harm. But a cat who regularly eats canine food, and eats little to no cat appropriate food, is going to wind up with serious health issues.

Cats are obligate (strictly) carnivores, while dogs are accepted to be omnivores. Cats have evolved from head to toe to eat other animals as 100% of their diet. This applies to all cat species, from our little domestic felines, up to massive tigers in the wild.

The teeth of cats are shaped and positioned to tear and rip at flesh, and their digestive system functions precisely to process the meat and other parts of their prey animals.

Formulated cat foods (the good ones I mean) are designed to emulate all the nutrients that a cat receives when they eat animal prey. Dog food is made for dogs and leaves cats nutritionally deficient.

This is what cats absolutely require in their diet, and why they need to be fed a cat-appropriate diet:

The most important and talked about component of the diet that is absolutely vital for cats is the amino acid taurine.

Cats do not generate taurine in the body, but dogs do. Cat food must contain adequate Taurine levels, otherwise it is not a suitable food to be feeding your cat. This includes dog food. Sadly, people who feed their cats (sometimes unknowingly) a fish only diet can result in a cat becoming taurine deficient.

This is one problem with low grade, cheap cat foods which should be completely avoided. Some of these foods even state on the label in tiny writing that it is “not a nutritionally complete” cat food – but most people never see or read this, despite their best intentions. It’s simple: low grade, cheap cat food puts cat health at risk in many ways.

Vitamin A

Cats need more vitamin A from their food than dogs do, because dogs are able to convert beta carotene from their food into vitamin A. So dog foods don’t necessarily have high Vitamin A levels, and certainly not a level required for cats.

Arachidonic acid

This is another fatty acid that dogs are able to make in the body, but cats require it from a food source.


While most dog food contain protein, dogs can make do with less protein and more carbohydrates and other energy sources. Cats being the pure carnivores they are, require a much higher percentage of protein in the diet for optimal health, and to get them as close as possible as their nature-intended diet.

Again, the best cat foods will have careful formulations and ratios of required nutrients.

There are some absolutely essential nutrients that cats must obtain in their diet, that aren’t necessarily vital for dogs. Because cats (all cats, from our domestic pets up to lions and tigers) are purely carnivores, 100% of their nutrition comes from the prey they catch, such as rodents and birds. This includes meat, bones, organs, skin, and even fur and feathers.

When feeding our pet cats we need to replicate these nutrients so that nothing essential is missing. This is why feeding a diet of purely raw meat, without including aspects of the other body parts of prey or supplementing with formulated cat food, leads to very dangerous nutritional deficiencies. Whichever method you feed your cat, we need to provide a complete diet.

That is the only way a cat is sure to be getting all of their vital vitamins, minerals and importantly, the amino acid taurine.