Honestly, Science Diet is not good. It's junk. If you want to find some really good quality foods try looking for
Canidae,
Innova, and
Timberwolf Organics.
Chicken Soup for The Pet Lover's Soul is good, too.
The ingredients of Science Diet Adult Original:
Chicken, Ground Whole Grain Corn,
Ground Whole Grain Sorghum, Ground Whole Grain Wheat,
Chicken By-Product Meal, Soybean Meal,
Animal Fat (preserved with mixed tocopherols and citric acid),
Corn Gluten Meal,
Brewers Rice, Chicken Liver Flavor, Soybean Oil, Dried Egg Product, Flaxseed, Potassium Chloride, Iodized Salt, Calcium Carbonate, Choline Chloride, Vitamin E Supplement, vitamins (L-Ascorbyl-2-Polyphosphate (source of vitamin C), Vitamin E Supplement, Niacin, Thiamine Mononitrate, Vitamin A Supplement, Calcium Pantothenate, Biotin, Vitamin B12 Supplement, Pyridoxine Hydrochloride, Riboflavin, Folic Acid, Vitamin D3 Supplement), minerals (Ferrous Sulfate, Zinc Oxide, Copper Sulfate, Manganous Oxide, Calcium Iodate, Sodium Selenite), DL-Methionine, preserved with Mixed Tocopherols and Citric Acid, Beta-Carotene, Rosemary Extract.
Chicken byproduct meal- consists of the dry, ground, rendered, clean parts of the carcass of slaughtered chicken, such as necks, feet, undeveloped eggs, and intestines -- exclusive of feathers except in such amounts as might occur unavoidably in good processing practices.
Animal fat is obtained from the tissues of mammals and/or poultry in the commercial process of rendering or extracting.
Chicken byproduct meal is an inconsistent ingredient because of the multiple organs used, their constantly changing proportions, and their questionable nutritional value. Chicken byproduct meal is much less expensive and less digestible than chicken meal, which Natura uses and which is considered the single best source of protein.
Animal fat- is a byproduct of meat meal processing. The origin of the contributing animals is never known, and the resulting oil is very low in linoleic acid -- an essential fatty acid that is important for skin and coat health.
Corn gluten meal- is the dried residue from corn after the removal of the larger part of the starch and germ, and the separation of the bran by the process employed in the wet milling manufacture of corn starch or syrup, or by enzymatic treatment of the endosperm.
Corn gluten meal is a low ash source of protein and acts as a urine acidifier in HealthWise Cat 'N Kitten formula. Cats vs Dogs: While not the best quality source of protein, the use of corn gluten in small amounts offer preventive health benefits for cats. In addition, unlike dogs, cats do not usually show signs of allergic reactions to corn products.
Brewer's rice- is the small milled fragments of rice kernels that have been separated from the larger kernels of milled rice.
Brewer's rice is a lower quality rice product that is missing many of the nutrients found in ground rice and ground brown rice. (See the descriptions for those ingredients.) Natura uses only whole ingredients, with their nutrients still intact.
Sorghum- is the ground grain of the sorghum plant.
Sorghum is a member of the grass family; its leaves and stalk resemble corn but it does not have ears. Although sorghum is a good source of carbohydrates, it is low in digestibility and therefore not used in Natura products.
Now compare that to Innova EVO:
Turkey, Chicken, Turkey Meal, Chicken Meal, Potatoes, Herring Meal, Chicken Fat, Natural Flavors, Egg, Garlic, Apples, Carrots, Tomatoes, Cottage Cheese, Alfalfa Sprouts, Dried Chicory Root, Taurine, Lecithin, Rosemary Extract, Vitamins/Minerals, Viable Naturally Occurring Microorganisms
http://www.naturapet.com/display.php?d=comp-wiz