Cats and dogs - the Western World's most favorite "pets" Unfortunately, all too often little distinction is made between these two different species who, in the natural world, commonly pursue one another as predator and prey: canines eating smaller felines, and large felines eating canines.
"Pet care manuals" usually group the two species with little dedication to the uniqueness' and special adaptations of each, and common belief goes about that one is like the other.

How much can we in fact apply the nutritional needs of one to the other? How much are cats like dogs?
Like humans, canines differ considerably from felines in their nutritional needs and ability to digest, assimilate, and synthesize nutrients.

Canines, although classified as carnivores, are omnivorous, and posses the ability to break down plant matter, as well as synthesize essential nutrients from such. Beyond analyzing their anatomy, canine behaviour clearly indicates that they are not solely reliant upon flesh for sustenance. Once having killed larger prey, such as an ungulate, they will penetrate the abdominal cavity to first eat the stomach and intestines of the quarry. Wolfs and other canines are also frequently observed eating fallen fruit, or fruit, like berries, off bushes.

Felines on the other hand have evolved as true carnivores, unable to synthesize essential nutrients from plant matter (unlike humans or dogs) These include the amino acids Taurine and Arginine, and the fatty acid Arachidonic Acids as cats can not de-saturate polyunsaturated fatty acids (vegetable oils), as well as vitamin A, which the cat can not convert from Beta carotene. Small cats usually eat their prey whole, but many still refuse stomach and intestines. Larger cats seizing larger prey, such as ungulates, penetrate the stomach cavity just beneath the Sternum to eat the liver, lungs and heart - usually avoiding stomach and intestines. Cats are also rarely observed eating plant matter (besides grass for regurgitation)

Canines and Felines also differ in their general requirements for macro nutrients. Cats require far more protein in their diet than dogs do - requiring at least 25% of dietary protein for energy conversion - whereas the dog has adapted to use carbohydrates to meet its energy needs. To the cat, carbohydrates can in fact be potentially deadly in excess, resulting in an alkaline body environment, obesity, and diabetes, and can lead to allergies resulting in general poor health or manifest as alopecia (self induced hair-loss)
Vegetables, or plant matter in general, is only minimally present in the diet of wild living cats. If so, it is only present in a pre-digested state, but never raw (other than some fruit in the meal plan of the Margay - Leopardus wiedi) Cats do not produce the enzymes in their body necessary for the break down of plant cellulose, therefore leaving plant matter undigested. To make the nutrients in plant matter, such as carbohydrates, available to the cat, it must be heat processed in order to break down cellulose. Even well cooked plant matter, however, can cause severe indigestion in the cat.
A pure source of carbohydrates is completely unessential for the cat, as the cat can rely entirely on protein and fat for energy conversion. Protein and fat is converted to Glucose by the liver, which then directly meets the body's energy requirements. Glucose is also used for synthesis of Glycogen ("Animal starch" similar to Amylopectin starch) in the liver and muscle tissue, providing a source of pure sugar to the cat through synthesis as well as through meat tissue of the prey.
All other essential nutrients required by the cat are provided through the soft tissue and bones of her prey, and are unnecessary from plant sources. This is what makes the cat so unique. In a way, the cat is taking a 'short cut' in nutrient acquisition by leaving nutrient conversion from plant matter to herbivores, to then simply dip into the full bowl by eating the herbivore. To afford such a gamble, every feature of the cat's body is in turn physically completely adapted to be the "perfect predator"
Canines on the other hand, never evolved these physical requirements and must therefore be able to rely on plant matter as a back-up source of sustenance, not demonstrating such predatory successes as family Felidae.

What is good for dogs is not necessarily good for cats. They are two very different species, and we should treat them as such.