Personally, I wouldn't feed it. Here's why (taken off of Royal Canin's website)
http://www.royalcanin.us/dogfood/yorkshire.html :
Ingredients
Chicken meal,
brewers rice, brown rice, chicken fat, chicken,
corn gluten meal, dried egg powder, barley, natural chicken flavor, cellulose, dried beet pulp (sugar removed), anchovy oil,
dried brewers yeast, potassium chloride, soya oil, fructo-oligosaccharides, salmon meal, calcium carbonate, sodium tripolyphosphate, choline chloride,
dried brewers yeast extract (source of mannan-oligosaccharides) , taurine*, Vitamins [DL-alpha tocopherol (source of vitamin E), inositol, niacin supplement, L-ascorbyl-2-polyphosphate (source of vitamin C*), d-calcium pantothenate, biotin, pyridoxine hydrochloride (vitamin B6), riboflavin supplement (vitamin B2), thiamine mononitrate (vitamin B1), vitamin A acetate, folic acid, vitamin B12 supplement, vitamin D3 supplement], magnesium oxide, borage oil, Trace Minerals [zinc proteinate, zinc oxide, ferrous sulfate, manganese proteinate, copper proteinate, copper sulfate, manganous oxide, sodium selenite, calcium iodate], glucosamine hydrochloride*, L-Carnitine*, DL-methionine, marigold extract (Calendula officinalis L.), tea (green tea extract), chondroitin sulfate*, preserved with natural tocopherols (source of Vitamin E), citric acid and rosemary extract.
There are too many fillers and carbs in it.
I just switched to Innova EVO small bites. It has the following ingredients: 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
As you can see, it's a much more natural dog food and is hi-protein, low-carb, and grain free!
Canidae and California Natural are great too!