Good question - but as far as my cats and dogs know -- nope! There is no difference. If I put the cat food down on the floor by the water dish, the dogs just wolf it down as if it were candy. I put the dog food down and the cats nibble at it with dainty little bites.

So, the cat food goes up on the counter where the dogs cannot get at it. I don't worry about the cats eating the dog food because when I feed them, 10 seconds later the food is gone - -they have no manners! I call them 'Hoover' because they are like vaccums when the food is out.

The cats, on the other hand, eat a morsel or two, then go wash themselves all the while looking distainfully at the dogs pacing around below the counter, whining for more food. Then the cats will go have another bite or two or perhaps patrol their territory from the tops of the furniture before eating again.

The dogs don't bother the turtle or fish food, but the cats occasionally try to get at the bird (not the bird food) because they think she is food. My house has more pets than people!

By the way, the dogs also think the people food is their food, too!