We do not recommend feeding your dog cat food on a regular basis, Deb. Cats and dogs have different nutritional needs and their food has been formulated to meet those specific needs. Cat food is higher in protein and fat, which may make it very palatable to dogs, but if you continue to feed your dog only cat food, over time you'll begin to see nutritional imbalances.
It's also possible to see gastrointestinal issues, such as vomiting and diarrhea, in dogs who continually eat cat food. That being said, the occasional cat food "snack" should not pose any serious health issues.
It's important to provide your dog with appropriate food for optimum health. We recommend a high-quality pet food that suits his age and lifestyle. For example, a puppy has different requirements than an adult dog, and an active or show dog has different requirements than a couch potato.