Cats are obligate carnivores, meaning they require nutrients found only in animal products. Their diet must contain a higher percentage of protein than dogs' diets. Cats also need specific nutrients like taurine, arachidonic acid, and vitamin A, which they cannot synthesize themselves and must obtain from their diet. Dogs, on the other hand, are omnivores and can derive nutrients from both plant and animal sources, making their dietary needs more flexible.
Dog food lacks the essential nutrients that cats require in sufficient quantities. For example, it typically contains much lower levels of protein and lacks taurine. A prolonged diet of dog food can lead to serious health problems in cats, including heart disease (due to taurine deficiency) and other metabolic imbalances.