Dog loves cat food.

My 3 year old mutt is in good health. I have always fed her high quality dog food. However, I now also have a cat and the dog strongly prefers the cat food. I know a steady diet of only cat food is not a good idea. However, is there any harm in mixing a small bit of cat food in with her dry dog food as part of a daily routine? When I do so, she eats her food instead of the cat's food. The portion of dog food she gets is the same as she would get without the cat food, so presumably she is getting the required nutrition from the dog food.

[Cliff Redford, DVM]

Great question...and a common one. You are correct that too much cat food for a dog is not a good thing. Cat food has a much higher protein and salt level and can be hard on the kidneys. You have to look at the cat food like junk food, or desert. While it is not good for us to eat junk food, a little bit is ok. So my general rule is that as long as there are not any diet related health issues (obesity, urinary disorders, diabetes etc) then up to 10% of a dog's food can be junk food...or cat food in this case.