When I had my cat, Mutant, she developed a food allergy. It manifested itself by her chewing the fur off her stomach. The vet gave her cortisone, but never mentioned the possibility of an allergy. Thankfully, I was steered to someone with knowledge of pet nutrition. She explained how cats and dogs can develop allergies to their food -- especially if the food contains corn and/or wheat. I immediately changed the food and, within two weeks, the fur chewing stopped and Mutant went on to live a good life. (Just FYI, the bad food was Science Diet, the good food was Halo's Spot's Stew.)

I work at a vet office and see a lot of cats with allergies. Years and years ago my parents owned a cat that was allergic to almost everything!! We thought we was even allergic to herself. I am not a fan of the Science Diet and if asked will direct people to a local natural pet food store in town. After reading your post I am not surprised Science Diet did this to your kitty.

I will never understand the success stories I hear regarding change of diets. I have seven cats left, lost 3 in less than a year. Science diet was the culprit. However, I am tired of trying everything under the sun and then throwing it out. Since the pet food scare (and even before I knew how bad the commercial food was) I tried every new product out, organic, raw and the list goes on. I still buy friskies and fancy feast and sometimes throw that out too. I have been cooking, chicken, liver, turkey, beef, people tuna, people canned chicken, cooked chickens, I always did include human foods too, but everyone likes something different and there is a lot of waste. I know you should introduce new food slowly. I have done that many times and throw it out because they wont touch it. Tried everything from Onjy Natural Pet. Halo stew they wont even lick. Merricks only lick sometimes. They lick Halo's freeze dried chicken but that is enough for one cat. Any new suggestions out there. I will be happy to try.

blue buffalo is a good one. i use it and though my cat has never had health issues, others i know who have used it for that swear by it. no by-products and no corn/wheat/soy fillers.

Blur Buffalo has several products in the day food line.  I don't like all the non cat friendly and even toxic ingredients.  

Sorry my previous post should have read dry food line, not day food line.

Cats who have eaten dry food all their lives can be extremely difficult to transition; we have a series of articles on this from way back in this blog, here are links:

http://onlynaturalpetblog.com/2008/03/14/why-switch-foods/

http://onlynaturalpetblog.com/2008/04/12/how-to-switch-foods/

You are absolutely correct, you *do* have to do it slowly, but a lot of folks get hung up on *how* slowly. This is not going to happen in a few days or even a week or two. I have clients who report their cat took many weeks or even months (as in 6 or 7 months!)  to make the transition. Here's the bottom line: you are the grownup here, and you're the one who decides what the cats will eat. Pick one food as a goal and do your transition to just that food over a time frame that suits your cats; that is, each time you make a change, it is small enough that the cats still eat the food. Continuously throwing new foods at them when they have not developed the palate or even the psychological ability to accept new things is naturally going to get you a lot of wasted food. Fortunately when I did this with mine, my dog was still alive, so nothing was every truly wasted (and I had a built-in enthusiastic consumer of everything that made *me* feel better, at least!). Now I can change foods every meal and they will eat it. But it took a long time to get to that point, and even now there are days when what I choose to put out is not in sync with what they like that day! Also cats' appetites do wax and wane. One day they'll scour every last molecule, and other days (especially in hot weather) they're just not excited about it.

Patience and persistence, and then more patience and persistence...that's what it takes!

I feed my cats merrick, azmira, eagle pack. They like the " fishy" flavors the best. I have heard that chicken and beef flavors  can cause food allergies.