Is dry food bad for my cat?
Short answer: Yes.
To understand why dry food isn't good for cats we really need to understand the evolutionary history of cats, so bear with me for a moment.
As far as we can tell based on archaeological and genetic evidence the domestic cat became the domestic cat it is today about 10,000 years ago in the Fertile Crescent in what is today the Middle East. They're from the desert so they're adapted to survive in desert conditions.
Desert adapted animals are really bad at drinking standing water. There's not a lot of standing water in the desert so they actually get most (some species get all) of their water from the food they eat. We're all mostly water remember. Cats just don't have a strong instinct to drink from a bowl of water since they didn't do that in the desert 10,000 years ago. Now they will eventually get dehydrated which sets off a whole set of reactions in the body which basically tell the brain “we need to drink water” and they'll finally lap a little out of a bowl but by the time they get that thirsty they're already dehydrated.
While we don't know exactly what life was like for cats 10,000 years ago we do know what life is like for wild and feral cats today and that's probably pretty similar to what their ancestors were doing. They spend the day alternating between sleeping, grooming and hunting/eating. They eat 5-7 mouse sized meals a day. Since they don't know if or when the next meal is coming cat's are basically “hard-wired” to be hungry all the time. They wake up, hunt, eat, groom, sleep, repeat.
Cats are obligate carnivores. They're lean, mean, efficient hunting, killing, meat eating machines. Now I don't subscribe to the theory that they should only eat proteins they would have eaten 10,000 years ago. But I do think that a diet that's primarily protein and fat and lower carbohydrates is biologically appropriate. Notice I said high carbohydrates are the problem not grain specifically? Unfortunately “grain-free” is a marketing ploy to get you to pay a lot of money for foods that are still high in carbs and not good for your cat. (Don't worry I'll have a post on how to decode the pet food labels and try to avoid pet food marketing ploys coming up soon.)
Ok so what does all this have to do with kibble?
All dry food shares certain characteristics which make it dry food. It contains minimal amounts of water. Most dry foods are under 10% water content. Dry food needs to be made with high amounts of carbohydrates. You just can't get cooked meat to stick together without carbohydrates. All dry food is sprayed in chicken fat. The cooking process burns off all the fat in the food so in order to get fat and fat soluble vitamins back into the food it has to be sprayed on at the end. Chicken fat is extremely cheap and so is used for this process. It may not even show up in the ingredient list since it only has to list ingredients that are a certain percentage of the food by weight and it's not enough weight to get included.
So we know cats are supposed to get most of their water from their food. What happens when you feed a cat let's say about ½ cup of dry food a day? She ends up getting about 20 mL of water from that. Now I know you're thinking, oh but my cat drinks a lot of water. Great! She only needs to drink about another cup of water to meet her hydration requirements for a day. She doesn't drink a cup of water a day does she? (Side note: if your cat is drinking a cup of water a day she probably has a medical problem and you should go to your vet). Remember cats aren't big water drinkers until they actually get dehydrated. So by the time you see your cat drink she's already dehydrated. That's not good. Chronic dehydration puts stress on the kidneys, the endocrine system, the heart and cardiovascular system. What problems do we commonly see in cats? Kidneys, endocrine (diabetes, hyperthyroid), heart. Obviously it's more complicated than just not feeding dry food since cats on wet food don't all live forever with no problems but chronic dehydration isn't helping anything.
Remember how cats need higher protein and fat and lower carbohydrates? That's not compatible with dry food. I know you feed the super expensive brand that says it's really high in protein. Turns the numbers you read on the package are totally misleading (more on this in my post on how to decode labels). Your super expensive dry food might say 24% protein and the canned food says 10% protein that's because the canned food is mostly water. Think of it as the difference between a protein bar and a bowl of stew. The protein bar is small and dry so most of it is protein, most of the bowl of stew is water, but there's actually more protein in the bowl of stew than in the dry bar. When you compare wet and dry food without the water the wet food actually is 40% protein. Way more than the dry food. And that's how it will always come out. It's just the nature of dry food that it must be made with higher carbohydrates.
So kibble is always going to dehydrate your cat and it's always going to be high in carbohydrates. It's also always going to have chicken on it which is a protein many cats have allergies to. Kibble just isn't good for cats and it shouldn't be fed to any cat in any amount ever.
Stay tuned for the next post debunking the myths and excuses people use to keep feeding kibble.