What's the big difference between cat & dog food?

[heightsyankee]

I know this may be the stupidest question ever, but my animals have some kind of species dysmorphia or something. The cats eat the dog's food at night and the dog eats the cats' food during the day, even though they have their own food.

One thing to note: our dog is an 18 lb terrier so his kibble is about the same size at the cats food.

Another note: we buy ours cats Iams. We buy our dog some very high end, all natural, grain free food because he has skin issues related to neglect by past owners.

[redheadbaker]

Dogs and cats are different species and have different nutritional requirements. I don't know specifically how the foods are different, just that they are.

Is it possible to get your cat on a higher-quality food? Iams is loaded with corn, and cats being obligate carnivores, they need a lot more meat than Iams provides.

[MissusTexas]

Cats require a lot more protein in their diets than dogs do, so if they are eating each other's food then the cat isn't getting enough of what it needs and your dog may be getting too much.

[SpicedApplePie]

I would try to resolve this somehow, like meal feeding both of them. Honestly, meal feeding is much healthier anyway. It is pretty easy to switch to meal feeding and most animals get used to it quickly.

Cat need a great deal of protein, and dogs need less. There are probably other differences, but I know this is the big one. Getting too much/too little protein can cause damage to the liver and kidneys.

[justaname]

Cat food will also be supplemented with more thiamine. It is an amino acid that cats must ingest to prevent severe neurological damage. Dogs (and humans for that matter) can synthesize it from another animo acid, lysine, so it isn't essential for them.