Food Trial: Which dry kibble should I use?

My cat George (7 months) likely has Eosinophilic Granuloma Complex that presents as linear tracks of plaques/granuloma on his rear legs and neck area. With the help of his vet, flea allergy has been ruled out, and the next step is a strict 6-10 week food trial.

George's vet has prescribed Royal Canin Selected Protein PR (rabbit), both wet & dry. George is a kibble addict, and during the 3 weeks we've had him, we've managed to get him to 40% dry, 60% wet.. so we'll be needing to use both types of the food. To add insult to injury, we won't be able to use any of the bribery we've been using to get him eating canned...so I expect he'll backslide in that regard.

That said, I'm appalled at the ingredients in the PR dry kibble.... peas is the first ingredient, but the hydrolyzed soy is what really bothers me. The soy is a new addition, as Royal Canin very recently reformulated their Selected Protein kibble line.

I am wondering if I could use Nature's Variety Instinct LID Rabbit formula for the dry portion of his diet. The ingredients in the PR canned aren't as quite as appalling as the dry, so I would use the PR for the wet portion of his diet.

Below are the ingredients for both kibbles. Would anyone be able to take a look and point out any red flags in the Nature's variety?  I only have a couple weeks to get him fully moved over to the new diet, as I need to do it before the most recent steroid injection starts to leave his system.

Royal Canin Selected Protein PR ingredients:
Peas, rabbit meal, coconut oil, pea protein, hydrolyzed soy protein, natural flavors, calcium sulfate, vegetable oil, sodium bisulfate, DL-methionine, monocalcium phosphate, fish oil, salt, taurine, choline chloride, monosodium phosphate, vitamins [DL-alpha tocopherol acetate (source of vitamin E), L-ascorbyl-2-polyphosphate (source of vitamin C), niacin supplement, biotin, riboflavin supplement, D-calcium pantothenate, pyridoxine hydrochloride (vitamin B6), vitamin A acetate, thiamine mononitrate (vitamin B1), folic acid, vitamin B12 supplement, vitamin D3 supplement], trace minerals [zinc proteinate, zinc oxide, ferros sulfate, manganese proteinate, copper proteinate, copper sulfate, manganous oxide, calcium iodate, sodium selenite], rosemary extract, preserved with mixed tocopherols and citric acid

Nature's Variety Instinct Limited Ingredient Diet Rabbit Formula ingredients:
Rabbit Meal, Tapioca, Canola Oil (preserved with Mixed Tocopherols and Citric Acid), Peas, Natural Flavor, Coconut Oil, Montmorillonite Clay, Potassium Chloride, Choline Chloride, DL-Methionine, Salt, Taurine, Vitamins (Vitamin A Supplement, Vitamin D3 Supplement, Vitamin E Supplement, Niacin Supplement, d-Calcium Pantothenate, L-Ascorbyl-2-Polyphosphate, Thiamine Mononitrate, Pyridoxine Hydrochloride, Riboflavin Supplement, Folic Acid, Biotin, Vitamin B12 Supplement), Minerals (Zinc Proteinate, Iron Proteinate, Copper Proteinate, Manganese Proteinate, Ethylenediamine Dihydriodide, Sodium Selenite), Green Tea Extract, Rosemary Extract.

I am definitely willing to use the PR kibble IF there are things in the NVI that would make it a bad choice, or if there are known issues with cross-contamination with other proteins during processing, etc. I keep telling myself it's only for a few months. That said, if the NVI is an appropriate alternative, I really would rather go that route.  What do you think? I really want to do this right, George is so young and has already had 3 injections of Depomedrol (2 while in rescue, 1 with us), so making a methodical attempt to try to find the cause of the EGC is our top priority. That darn soy in the PR just really bugs me....

Also, because it may come up in the discussion... I am not opposed to raw in the future. But I have about 2 weeks to get him on a single novel protein diet. I don't trust myself to learn about proper raw feeding, AND also convince him to eat it in that time frame. That is why my focus at the moment is on commercial diets only.

Thanks for any input you can offer.

A lot of people use the Natures Variety Limited for food allergies, but just to be on the safe side, I would run it by my Vet. 

And I had heard about this change that Royal Canin made using Hydrolyzed Soy.  I think it resulted from some sort of shortage of the previous ingredient, but heard they are working on it because it has a lot of people up in arms

As you know, Sebastian is currently on the Royal Canin PR formulas (mostly canned; a little dry). I was up in arms about the new addition of hydrolyzed soy protein in the dry food. Grrr...    I decided to continue to offer it to him...for now...but I've cut the amount in half. He still likes the food and has no qualms about the soy, so he's very unhappy with the reduced amount. Chances are I'll always have the dry on hand for emergencies and "tough times". When Sebastian has flares, he becomes anorexic, and I need him to eat something. The dry usually gets him going.

I went with the PR dry for couple reasons, the main one being that Sebastian didn't like the Nature's Variety LID rabbit. I really don't know what to think about cross contamination and the chances of other proteins being mixed in with the food, but RC swears by it's quality control and that this will not happen. Who really knows, though.   Overall, I like NV better as a company. I give the LID Turkey dry formula to Caesar who is a former kibble addict, but now gets both wet and dry.

Most places (at least in my area) will let me return food as long as bags are more than half full and cans are unopened (obviously). My vet will let me return food that goes unused or that the cat doesn't like or I can exchange it for something else.

Thanks for your input!

I did ask at George's appointment on Saturday, if there was a commercially prepared food option. Big thumbs down from the vet about that. At the time I hadn't researched it, so I didn't ask about the NVI specifically. 

Hubby and I talked last night, and I think we are resigned to (grudgingly) use the PR dry. We'll do it by the book and see what happens. It just boggles my mind that soy is being used in a low/non-allergen diet. I know it is hydrolyzed, but still it bugs me.  I know RC states they're having problems sourcing their usual proteins. But I'm not sure if I believe it's as bad as they state.  Soy is cheaper to use, and multiple pet stores in my area have shelves fully stocked with NVI LID rabbit!  So, the rabbit at least isn't proving difficult for others....

We tossed a few PR kibbles in with George's usual (Wellness Core) last night, and he ate them up. So, we'll start mixing it in slowly this week with hopefully no tummy troubles so we can hit the ground running when the canned arrives. Fingers crossed that he'll like the canned too. The only way he'll eat his usual stuff now is if I crumble freeze dried chicken into & all over it. I'm obviously not going to be able to use that during the food trial (and I haven't located any freeze dried rabbit bits!).  Crumbled kibble isn't a proper substitute in the world according to George!

Thanks again for the replies!

You want freeze dried rabbit, here's some   http://www.glennsmarket.com/Section...at_Freeze_Dried/6_oz_Freeze_Dried_Rabbit.html. 

I buy Stella and Chewy's rabbit even though it's for dogs, and my cats like it.  But it's got a few other things in it besides just plain old rabbit.  I believe this item (above) is simply rabbit

Here's another one:  http://www.powerpawproducts.com/frdrra4oz.html

Thank you so much for the links to the freeze dried rabbit! If George is stubborn, we'll definitely be ordering some!