What Happens if a Dog Eats Cat Food for a Long Time?

Cats require a higher protein diet than dogs because they are obligate carnivores, meaning that they need to eat meat from animal sources. Dogs, on the other hand, are omnivores and don't need as much protein as cats do, nor do they necessarily need the majority of their protein from animal sources. Commercial dog food must contain a minimum of 18 percent protein to meet your pup's basic nutritional needs. This need has been determined by the nutrient profiles established by the Association of American Feed Control Officials, according to the U.S. Food and Drug Administration. Cat food contains a minimum of 26 percent protein, 8 percent higher than dog food.

Not only does cat food contain more protein than dog food, it also contains higher amounts of fat. AAFCO recommends a minimum of 5 percent fat for dog food and 9 percent fat for kitties, according to the FDA. While this might not seem like such a big difference, the higher amounts of protein and fats mean more calories for your pooch. Such rich foods can cause him to become obese if eaten for a long period of time. In addition, because your pup's system wasn't designed to digest fatty foods, it can cause stomach upset, vomiting and diarrhea in your furry friend, according to the Veterinary Associates.

In addition, cat food contains an improper balance of vitamins and minerals for your pooch, leading to deficiencies or excesses of these ingredients. For example, cat food contains less zinc and vitamin E than dog food. Cat food also contains taurine, something that dog's don't need in their diet. These nutritional differences can affect your dog's overall health over a long period of time. Dogs also need more carbohydrates than cats and won't get the energy they need without these ingredients in their food. Your pup can eat a diet containing almost 50 percent carbohydrates to give him energy, while a kitty gets the majority of her energy from fats.

High-protein diets, around the amounts included in cat foods, are appropriate for active, show dogs or growing puppies, but not for older or ill dogs. These types of foods are hard for your little one to digest. If your dog suffers from kidney disease, feeding him a high-protein diet can put a lot of stress on his kidneys, worsening his condition. Because health conditions like diabetes can also affect your pup's kidneys, high-protein diets aren't recommended for diabetic dogs either.

Feed your pooch food designed for dogs to avoid health issues. If you also own a cat, the temptation of your kitty's food could be hard for your pup to resist. To avoid your dog eating your cat's food, feed your kitty in a separate room that your dog doesn't have access to or on a high shelf or counter. Monitor feedings to make sure that each pet eats his own food.