Have you considered real food instead? Much healthier. The reasons our companion animals are dieing in epedimic porportions for serious illnesses and cancers is due to commercial foods and snacks, over inoculating and insect repellents.
The most important book on feeding pets is by Ann N. Martin and I would highly recommend you buy and read it before you feed any type of kibble.
Amazon.com: Protect Your Pet: More Shocking...
More reading:
Food Pets Die For; a Book Excerpt food even a dog shouldn't eat Rendering: the "Invisible Industry" Gets a Green Facelift | Center for Media and Democracy Welcome to Born Free USA united with Animal Protection Institute http://www.chron.com/cs/CDA/story.hts/front/1377004 Holistic Animal Medicines :: Natural animal health products supplier