The short answer: It is not recommended.
The long answer: In the same way that dogs shouldn’t eat cat food, cats should not eat dog food because they do not contain the necessary nutrients cats need to thrive. Dogs are omnivores so their food is a mixture of meat, grains, and vegetables, while cats are carnivores that need meat for their body systems to function properly.
Though some dog food brands may have high protein content (about 18 to 26%), cats need a higher level of protein percentage (30 to 34%) in their meals. Plus, they also need taurine, arachidonic acid, and vitamin A—essential nutrients that are not commonly found in dog food.
What to do if your cat accidentally eats dog food: If your cat tried a small bite of your dog’s food, there’s no need to worry! However, if your cat eats dog food on a regular basis, this will not be good for her overall health. She could become lethargic and lose muscle mass.
In summary: Unless it is an emergency, refrain from feeding your cat or giving her access to dog food. The nutritional content of dog food will not benefit your cat at all. Detrimental or even lethal consequences can occur if you decide to feed your cat dog food for prolonged periods of time. Check out what your cat can safely consume in our “can cats eat” category.