My Shepard/Collie mix always eats the cat's food. She then gets diarreah (sp?) and poops in the basement sometime while we're sleeping. She goes outside to potty a few times during the day, but she still goes in the basement.

Is there any way to make her stop eating the cats food? I can't put it up anywhere, the parents don't want the cats to eat on the table or on the counter. That and the dog could get to it if I put it on a table or counter (she's a big girl).