Is it ok to mix the dog food and the cat food and let them all eat out of one bowl?

I have 2 small dogs and 2 cats. You see, the dogs raid the cat food bowl and then eat their own food once the cats is all gone. I figure, why keep trying to discipline the dogs? Theyre pretty sneaky about it now, and im always having to give the cats more food. Is there anything wrong with dogs eating cat food, or cats eating dog food?