Advice from someone w/o a dog!
Pam,
My guess is that a nibble/kibble or seven from a dog's dish can't be any worse than eating, well, lets say, as mouse. I suspect a steady diet of dog food would land your kitty in the Vet's waiting room. I would discourage it, for sure, but wouldn't worry unless the kitty spends all of his time at the dog's food. The dog will probably wise up and eat all of her food at one sitting. I call that competitive eating - it happens often in multiple pet homes. My cats are good that way - the often leave food for later and don't chow down. This includes Gabe, by the way.
You may want to check with your Vet the next time you go for a visit. Free advice is nice, as you write out your check for the many dollars in maintenance fees/services/shots! I am sure I have paid for camp for at least three of my Vet's kids.
P. S. Gabe was a real sweetie this AM. We had some one on one since G & M were in their daily nap mode. All is quiet here. We have our moments, but in general, I give this change a very, very high mark.