Cat vs Dog Food
What's the real difference between cat and dog food? Would it really cause a problem if you fed your dog cat food, or your cat dog food, or is it all just marketing?
These are fantastic questions that I think we’ve all had at one point or another, and in order to answer them, we have to dive into our furry friends' biology! A better question would be: what is the difference between a dog and a cat's nutritional needs? As we’ve discussed in previous posts, not all pet food is biologically appropriate, so the difference between the species' diets doesn't really matter. Okay, it still matters, but when the cat food or dog food you’re looking at is mostly made of rice or oats, you’ve got more things to consider than the difference between the two. For the sake of conversation, let’s assume you’re looking at a biologically appropriate diet consisting of raw food that comes complete and balanced as is; you don't need to add anything to it, you just pop it in their bowl.
Cats and dogs both fall under the order "Carnivora" when it comes to their taxonomy. So, they’re both carnivores and more interestingly, they're both predators. The difference is the type of carnivore they are. Dogs are simply carnivores, sometimes referred to as "facultative carnivores" and often confused with being omnivores. You may have heard that dogs are omnivores when talking with people about dogs nutritional needs, and it’s a massive "supportive argument" used for pet parents and brands who believe dogs can be vegan or vegetarian. Spoilers, they absolutely cannot be vegan or vegetarian. Dogs getting classified as omnivores is strictly because large pet food companies have an economic benefit to convince you dogs have a need for carbohydrates and other filler ingredients commonly used in popular pet foods. Science doesn’t support this claim, but unfortunately there is nothing stopping anyone from spamming the internet with this "fact". From a biological perspective, dogs are direct descendants from wolves and they only need meat and animal products to not just survive, but to thrive. Everything else is extra, consumed out of convenience or necessity to survive. That's the key to the term, "facultative carnivores". Dogs will consume plant matter, carbohydrates, fruits, etc… if it’s easily available and lot’s of fruits and vegetables are packed full of good stuff for dogs. Pumpkin, blueberries, carrots, green beans, sweet potatoes, strawberries - they’re all packed with vitamins, minerals, antioxidants and more, but none of them are essential for a dog's diet, they’re just a great addition. Most importantly, unlike omnivores, dogs can’t pull protein from non-animal sources. For example, if you look at a bag of pet food and see that it’s 26% protein, they’re not just talking about meat and other animal products. That percentage also counts plant products that contain protein and things like soy, quinoa, buckwheat, barley, oats, peas, and chickpeas all count towards the amount of protein on the bag. This is one way pet food companies are able to trick consumers into thinking their food is better than it is, but we’ll get into the manipulation of marketing on pet food bags in another post. People are omnivores, so we are able to pull protein from these plant sources and that’s why it’s possible for humans to go vegetarian or vegan as they can technically get everything needed for a balanced diet without getting meat/animals involved. Or on the complete opposite, people can also go completely carnivore because we’re designed to pull nutrients from both sides just as easily. Dogs can’t do that and protein is the most important part of a dog's diet.
So, to review as “facultative carnivores” dogs do benefit from non animal products like fruits and vegetables, but they can’t pull protein from them and they have to have meat and other animal products like bones and organs to thrive. That was a little all over the place, but hopefully we’re on the same page.
What about cats?
Cats also fall under the order “Carnivora” when it comes to their taxonomy, but unlike dogs, they aren’t facultative. Cats are what we call “obligate carnivores,” also called “hypercarnivores,” and the simple explanation of this is that cats are biologically designed to eat meat and other animal products, and that’s it. Essentially, if it doesn’t come from an animal, not only do they not need it, their bodies aren’t designed to process it. Personally, cats are easier to understand. All you have to do is ask yourself, “did this come from another animal?” If the answer is no, then it’s not necessary. This feels like a simple concept, but unfortunately, pet food companies seem to be lacking on this piece of information and most commercially available cat foods are packed full of ingredients that cats can’t process appropriately. Next time you find yourself shopping for cat food, check the ingredients on a few foods. If you grab some of the more popular options available at most grocery stores, it won’t take long for you to find a few where the first ingredient is corn or rice, and that means the heaviest ingredient is something they not only don’t need, but can’t use. Other animals that fall into this same class of obligate carnivores include polar bears, big cats like lions, tigers, cheetahs, etc… crocodiles, vultures, and snakes. When you think about animals like these, it’s completely reasonable to picture the food you’d feed them: meat and other animals. Well, our cute little house cats have the same nutritional needs and requirements. Cats are just typically more open to eating non-animal products than, per se, snakes.
As imprint eaters, it can also be difficult to change their diet if they’ve been eating something like kibble for an extended period of time. Humans meet our blood sugar needs with carbs, cats meet theirs through meat and if their diet is lacking in animal-based proteins they will start to break down their own organs and muscle for energy. Earlier I mentioned their bodies aren't designed for foods that don’t come from animals and I plan on writing a more in-depth post about this so I’ll keep it short here, but essentially they lack critical enzymes and their digestive systems are too short to break down things like plant matter. Being obligate carnivores alongside evolving from desert dwelling wildcats is also a reason you typically won’t see cats drinking from a bowl of water like you do dogs as often. They’re built to get the majority of their hydration needs from the food that they eat, and if you want to read more about cats and hydration, check out our blog post “Is Your Cat Dehydrated?”
Alright, so now we have a very basic understanding of what makes cats and dogs different from a biological standpoint when it comes to their nutritional needs, but what exactly is the difference between cat and dog food, then?
For the sake of keeping things easy, we’re going to assume the food you’re looking at is a biologically appropriate, high-quality diet. That way we know the food is meeting their needs generally and we’re only focusing on the difference between the two. Below I’ve added some photos of Viva Raw’s Chicken Recipe for both cats and dogs to compare the ingredients of a food that is both biologically appropriate and keeps their ingredients filler and nonsense-free.
The most crucial difference is how the foods break down the ingredients percentage-wise. The dog recipe is made with 90% chicken, bones, and organs, 8% fruits and veggies, and 2% supplements. The cat version is made with 98% chicken, bones, and organs, and 2% supplements. I’m sure you noticed the most obvious difference is the lack of fruits and veggies in the cat food, which is understandable since cats don’t need them, but there are other differences you may not have noticed. The supplements are fairly different as well, but the main and most important difference other than the percentage breakdown is the added taurine in the cat food.
So, what even is taurine? Good question. Taurine is an amino acid that plays many roles inside not only cats' and dogs' bodies, but ours as well. It's super important for keeping vision sharp, digestion on track, and heart muscles working well. Plus, it's essential for keeping the immune system strong and ensuring healthy pregnancy and baby development. Humans and dogs are able to synthesize enough taurine from methionine and cysteine (other amino acids) to use, but cats don’t have the proper enzymes and can’t produce it on their own, not enough at least, making taurine an “essential amino acid” for cats. That is why you’ll see it in the ingredient list on cat food of all kinds. Alongside cat food typically being higher in animal ingredients and including the added taurine, cat food is also usually more calorie-dense. Using our same Viva Raw Chicken example, the dog recipe is 35 calories per ounce and the cat is 40 calories per ounce. You’ll probably see different sizes, shapes, and textures between the two as well, and that's mostly just because cats are typically more picky and usually smaller.
A lot of brands that really care about their product will take an extra step to ensure their recipes don’t just meet the nutritional needs for both cats and dogs individually, but that each recipe is tailored to what they will enjoy the most. Going back to our Viva Raw example, both recipes use mussels, but the dog recipe uses green-lipped mussels whereas the cat recipe uses Chilean blue mussels. After chatting with one of the owners of Viva, I found out they do this because blue mussels are higher in manganese, which, if you read our Deep Dive on Furry Chews, you’ll know all about. In the dog recipe, they use ginger for added manganese, but cats would most likely not enjoy the taste or smell of ginger, so instead, they just swapped out the type of mussels. Little details like this can make a big impact on not just the quality of the food, but how likely our pets are to actually love their food.
So, pop quiz - do you think it’s okay to feed cats dog food and vice versa? If you answered no, you are correct! Dogs could technically do fine eating cat food for the most part since although they do get benefits from fruits and veggies, they don’t need them. However, I don’t recommend it simply because it’s not necessary to do, and they would likely gain weight since cat food is more calorie-dense, remember? Cats, on the other hand, definitely can’t eat dog food long-term because it lacks the essential nutrients they need like taurine, and the excess ingredients will have an impact over time as well. That being said, the occasional slip-up won’t do any harm. So, if you run out of cat food or dog food and can’t make it to the store, don’t panic. If they’ll eat it and you have some of the other, just use that for the night.
All-in-all understanding the unique nutritional needs of our pets is crucial for their health and well-being. While cats and dogs may share similarities as carnivores, their dietary requirements differ significantly. While the occasional deviation from their species' appropriate diet may not pose immediate harm, it's best to prioritize feeding biologically appropriate, high-quality food to ensure our furry friends receive the nutrition they need to not only survive, but to thrive.