Published by: Ingrid King. Last Updated on: July 7, 2023 by Crystal Uys

tabby cat eating cat food out of bowl inside

We’ve all heard some of these:  Dogs come when they’re called called; cats take a message and get back to you.  Dogs believe they are human; cats believe they are God.  If a dog jumps up into your lap, it is because he is fond of you; but if a cat does the same thing, it is because your lap is warmer.  Cats act and respond differently than dogs.  You’ll never see a cat wag his tail.   Dogs’ reflexes are quick, cats’ reflexes are incredibly fast.  Dogs prefer action, cats prefer watching first.  Maybe the cat is America’s favorite pet because cats are, well – different!

The differences between cats and dogs become particularly evident when it comes to their nutritional requirements.  Even though both species are considered carnivores, cats are obligate carnivores, which means that they need meat in order to thrive.  In fact, cats cannot survive without at least some meat in their diets.  Dogs are considered omnivores – they can survive on plant material alone; however, they, too, do best on a diet made up primarily of meat.

Why do cats need meat to thrive and survive?  Dietary protein supplies amino acids and is needed for the manufacture of antibodies, enzymes, hormones, and tissues. It provides energy and is essential for growth and development.  Protein derived from meat and poultry contains ample amounts of these essential amino acids, whereas protein in vegetables and grains does not provide these.   More importantly, unlike dogs, cats lack the enzyme required to process vegetable-based proteins metabolically.

cat eating raw chicken from metal bowl
Image Credit: ophiecat, Shutterstock

Another significant difference in nutritional requirements is cats’ need for taurine, which is  important for proper functioning of the heart.  Meat is a natural source of taurine; it is not available in plant tissues.  Dogs can make their own taurine, but cats cannot.  Commercial cat foods did not contain this important amino acid until 1987, when veterinarian Paul Pion identified the link between a lack of taurine in cats’ diets and feline dilated cardiomyopathy, a fatal heart disease that has been largely eliminated in the pet cat population since then.

So what should you feed your carnivore?  The ideal diet that most closely mimics what cats would eat in the wild is a properly supplemented raw diet.  There are several reputable resources available online to learn more about raw feeding, two of the best are Dr. Lisa Pierson’s Feeding Your Cat:  Know the Basics of Feline Nutrition and the Feline Nutrition Education Society.  Raw feeding does not have to be complicated or a lot of work; fully supplemented commercial frozen raw diets are readily available and all a cat owner has to do is thaw and feed.

raw cat food
Image Credit: stockcreations, Shutterstock

However, not every cat owner will want to feed raw, and there are other, healthy alternatives available.  A home-cooked diet can be a good option for cat owners who like the idea of controlling the ingredients in their cat’s food and don’t mind the extra work these diets require.  Proper supplementation is key; a great resource for preparing nutritionally complete homemade diets is  The next best thing to feeding raw or homemade is feeding a quality grain-free, canned diet.  Look for foods that list meat as the first ingredient.  Be aware that with the recent popularity of grain-free foods, some manufacturers are now taking grains out of their foods, but are adding other carbohydrates such as sweet potatoes and peas, and as a result, some of these diets are still too high in carbohydrates.

Cats should not eat dry food.  Cats need moisture in their diet, and feeding only dry food is considered to be one of the most common causes of bladder and kidney problems.  Even though cats who eat a predominantly dry diet will drink more water, they still only get half the amount of water a cat eating canned food will get, even after adding all sources of moisture together.  If you must feed dry food, at the very least, consider feeding one of the grain-free varieties, and supplement with canned or raw food.

Regardless of what type of diet you choose to feed, never feed cats free-choice.  Free-choice feeding, which means leaving food available for the cat all day long, is the primary reason why feline obesity has become an epidemic.  Cats by their very nature are hunters:  they kill, and then eat their prey.  They do not graze throughout the day.  Feeding two meals a day, appropriate in size for your cat, will go a long way toward keeping kitty fit and trim.  What is a normal sized meal?  Consider that in the wild, a mouse would constitute a typical meal for a cat.  Manufacturer recommendations may not be your best guide when it comes to portion size – they’re usually much higher than what your cat really needs.  When in doubt, consult with your cat’s veterinarian.

Man shopping in supermarket reading cat food label product information
Image Credit: LADO, Shutterstock

I’ve been feeding my cats grain-free canned food for a number of years with wonderful results.  I recently transitioned Allegra, who just turned one, to raw food, and I now alternate raw and grain-free canned food, with raw food taking up the bulk of her diet (about 75%).  I’m also a firm believer in variety and rotate brands and flavors.  Cats can be finicky, and by exposing them to a variety of choices, they will not only be healthier (no one food can be complete and balanced, no matter what the manufacturers tell you), they also won’t get stuck on eating only one thing and refusing everything else you offer.

So – what are you feeding your carnivore?

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15 Comments on Differences in Cat and Dog Nutrition Based on Science

  1. My precious little furry girls (just now going on 4 months old) are lovers of Solid Gold and Natural Balance wet but I alternate it with a variety of other grain free wet brands. (Cleopatra is Miss Finicky but little Miss Wallis is not picky at all… Sisters, go figure, eh? :))

  2. When you talk about rotation, do you mean different foods and labels, or just different meat sources? I have been feeding my cats Instinct Raw Bites (frozen and thawed) and rotating the different meat sources – rabbit, duck, venison, chicken, beef (no fish). They seem to be thriving but I just want to be sure I’m doing the right thing. I also spinkle Wysong’s F-Biotic powder on every meal. Thanks!

    • Rotation can mean both, Marilyn: different brands, and/or different protein sources. Here’s more information:

  3. I have two cats and at $1.39 (or even up to $2.99) a pop for a can, with the absolute lowest price I have found for wet food being $.69, I can’t afford to feed my cats a completely wet food diet as I would like. However, as I care very much about my cats’ health, I do make sure to feed them wet food every single night for their dinner. I know it’s not completely ideal, but for us who MUST unfortunately penny pinch, I believe it is better than how most cats live. If I am ever in a position to do so I will feed my cats a completely wet diet but for now, it’s grain-free kibble in the morning, tasty Weruva, Almo or BFF at night.

    I also firmly believe in rotation feeding. When I was a kid (before I was educated about cat diet) we used to buy a different brand of kibble every pay day – we NEVER had ANY problems with digestive upset!

    Do you have any recommendations for cat guardians like me who are not very well financially endowed? I understand that being poor is not the best situation for a cat but I figure that a poor, loving home that tries as hard as it is able is better than no home at all (or euthanasia) for a kitty.

    • It sounds like you’re doing the best you can within your budget, Rosanna! You can find the brands I recommend here: I’m not familiar with Almo, but Weruva is an excellent brand. I don’t like BFF quite as much because all the flavors contain fish, something I try to avoid. I, too, think rotation feeding is important. You’re doing great – keep it up, and when you can, switch to an all canned diet.

  4. I am a flight attendant so I have to leave my cats alone often. I can see this wet food diet working when I’m home but impossible when I’m flying since I live alone. What should I do? Is it bad to flip flop from wet food when I am home and then the dry free for all feeding when I’m flying all over the place? Your thoughts. Thanks.

    • Flipping back and forth is not “bad,” it’s better for your cats to at least get some canned food, even if they can’t have it all the time, but it would be better if you eliminated dry food altogether. Ideally, you would have a cat sitter come and feed your cats and spend time with them on the days when you’re flying. There are some timed feeders you can try that have cooling compartments, so you could leave those out filled with canned food, but it’s not ideal, and I don’t think they would work for more than 24 hours. However, for what it’s worth, I don’t think cats should be left alone for more than 24 hours.

      If none of the above is an option for you, then I’d at least make sure that the dry food you feed is a grain-free one, and feed all canned when you’re home.

  5. I’ve not met too many cats who tolerate brushing, Weetzie. Using the dental kibble as an occasional treat is probably fine, although I don’t think it will do much to prevent tartar. Most cats don’t chew long enough for the scraping action that is the theory behind these dental diets to take place. Additionally, dry food can leave a carbohydrate residue in the cat’s mouth that actually encourages growth of tartar and plaque.

    Thanks for adding us to your blogroll!

  6. My 5 kitties all eat EVO 95% protein canned food, and I rotate through the Chicken/Turkey, Duck, Beef, and Venison varieties. They seem to really like all of them, but prefer them in this order: Venison, Duck, Beef, Chicken/Turkey. This is funny to me because I relatively sure that a cat, in the wild, wouldn’t be able to take down a deer, and would likely have trouble with most ducks.

    Anyway, keep up the great work of spreading the news that cats are carnivores and don’t need plants!

  7. I agree, I’ve never had any problems with rotating grain-free canned food either.

    I feed our cats a variety of grain-free, good quality canned food. But, I do give them a spoon or two of the dental kibbles my vet recommended. I’d prefer not to, but one of them has some gum issues and that’s how we’ve dealt with it. And yes, I tried brushing – but she is a very, umm, “independent spirit” as was simply NOT having it!

  8. Layla, with grain-free foods, digestive upsets tend to not be as much of an issue even when rotating brands and flavors, but of course, it depends on the cat. I’ve never had a problem with any of my cats with rotation feeding. It’s usually the grains in the foods that cause the GI issues.

  9. Obesity plagues people and pets in this country and we don’t have to look any further than our diet to see why. I agree with rotating brands and flavors but gradually. Any sudden changes can upset digestion. Yes, dogs and cats are carnivores, and it drives me batty when vegetarians feed their pets no meat. All we have to do is look at their teeth to know what to feed them. The canine teeth say it all.

  10. Michael, I’ve heard numerous, albeit anecdotal, accounts of diabetes being reversed when cats are fed a species appropriate diet high in protein and with low or no carbohydrate content. Elizabeth Hodgkins, DVM dedicated an entire website to this issue:

    Hill’s had the right idea with the m/d diet as far as the higher protein content, however, I don’t like any of the ingredients in this diet, including the protein source (pork). The diet contains far too many by-products, and it also contains a variety of carbohydrates that I believe defeat the purpose of what they’re tyring to achieve with it (cellulose, corn starch, rice flour, to name a few).

  11. I believe one of the main reason for obesity is the amount of carbohydrate in the diet, it alters the metabolism, and stresses out the pancreases, leading to the diabetes. Hills have a new food out called M/D that has a very high protien content, and this has been shown to reverse the diabetes.

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