Food sensitivities?

Sprout was having very stinky pudding-like poop for several weeks, basically since shortly after we brought him home. Brought a sample to the vet, but the fecal was negative. The vet gave me "hypoallergenic" food to try, and now after two days of feeding that he has had not one icky poop. (Compared to two icky poops per day before.) I'm unsure if it's premature to say that food sensitivity is definitely the culprit, but that is the direction I'm being led at this point. So now I am left to figure out what to feed my kitties.

I could continue to feed Sprout this Rx food if I have to, but I'd prefer to try something that I can feed all my cats and don't have to get to the vet's office during open hours to buy. The food I was feeding him was regular Innova (not EVO). Here is the Innova ingredients list:

Turkey
Chicken Meal
Chicken
Potatoes
Egg
Barley
Chicken Fat
Rice
Herring
Sunflower Oil
Apples
Carrots
Lactose-Free Milk
Herring Oil
Taurine
Potassium Chloride
Alfalfa Sprouts
Vitamin E Supplement
Ascorbic Acid
DL Methionine
Choline Chloride
Direct-Fed Microbials
Vitamins/Minerals

In contrast, here is the ingredients list for the food the vet gave me that seems to have solved Sprout's problem, which is an Iams Veterinary Formula:
Lamb Broth
Lamb Liver
Lamb Tripe
Lamb
Ground Pearled Barley
Lamb Meal
Corn Oil
Dried Beet Pulp
Potassium Chloride
Choline Chloride
Salt
Taurine
Vitamins
Calcium Pantothenate
Biotin
Pyridoxine Hydrochloride (source of vit. B6)
Vitamin B12 supplement
Riboflavin Supplement
Folic Acid
Menadione Dimethylpyrimidinol Bisulfite (source of vit. K)
Minerals
Calcium Carbonate
DL-Methionine

I've highlighted in red the ingredients that are common to both foods, so I'm assuming I can exclude those as being problematic. (Apparently the barley is fine, for example.) Anyone have a clue what the most likely culprit is that is upsetting his tummy? Should I try to switch to a lamb-based food, or just move AWAY from chicken or turkey? (And of course, I just bought a case of Wellness Chicken formula! )

I would wait another week but yes research lamb foods avail to you

In contrast, here is the ingredients list for the food the vet gave me that seems to have solved Sprout's problem, which is an Iams Veterinary Formula:
Lamb Broth
Lamb Liver
Lamb Tripe
Lamb
Ground Pearled Barley
Lamb Meal
Corn Oil
Dried Beet Pulp
Potassium Chloride
Choline Chloride
Salt
Taurine
Vitamins
Calcium Pantothenate
Biotin
Pyridoxine Hydrochloride (source of vit. B6)
Vitamin B12 supplement
Riboflavin Supplement
Folic Acid
Menadione Dimethylpyrimidinol Bisulfite (source of vit. K)
Minerals
Calcium Carbonate
DL-Methionine

Click to expand...

I think Nature's Variety Instinct canned Lamb formula might work. Here's the info on that:

Ingredients:
Lamb, Lamb Liver, Lamb Broth, Flaxseed, Eggs, Tricalcium Phosphate, Peas, Carrots, Lecithin, Potassium Chloride, Vitamins (Choline Chloride, L-Ascorbyl-2-Polyphosphate, Vitamin E Supplement, Niacin Supplement, Vitamin B12 Supplement, Vitamin A Supplement, Thiamine Mononitrate, Biotin, Riboflavin Supplement, d-Calcium Pantothenate, Pyridoxine Hydrochloride, Vitamin D3 Supplement, Folic Acid), Dried Kelp, Salt, Taurine, Minerals (Zinc Proteinate, Iron Proteinate, Manganese Proteinate, Copper Proteinate, Sodium Selenite, Ethylenediamine Dihydriodide), Artichokes, Cranberries, Pumpkin, Tomato, Blueberries, Broccoli, Cabbage, Kale, Parsley.

Guaranteed Analysis %:
Moisture (max) 75
Crude Protein (min) 9
Crude Fat (min) 7
Crude Fiber (max) 3

What do you think Sharky?

it may be worth a try .. my worry would be flax and peas can also be issues

It is much harder to find lamb formulas for cats than it is for dogs!

Yes it is ...

Acana has a new GRAIN free lamb .. you likely can find if you have access to Orijen

Hmm... I've never even heard of that brand before. I don't think they carry it at any of my local stores, but I will check into it. I doubt it, because I think the one store that used to carry Orijen no longer has it available.

Right now I have enough of the Rx food to last through the end of this week. If Sprout continues to have no problems on this food, I will go forward with trying him on other lamb formulas. I'm thinking I will try the Instinct and see if he can tolerate it. (As far as I can tell it is the only lamb formula that is easily available to me, and that's assuming my local store carries that particular formula. I know they would order for me if I asked, though.) I will just keep the other cats at status quo until I figure out what Sprout can handle.

If that doesn't work, I'm not sure quite what I'm going to do yet! I always have the option of keeping him on this Rx food until I find something else, I suppose. Are there any other proteins that might be worth trying, like Rabbit or Duck? It seems like practically EVERYTHING has chicken in it!

Also, do you think it makes any difference if he's eating dry/canned/raw, as far as sensitivity is concerned?

Rabbit would be next.. duck is not a fave since many foods( wet have some thus it is less "hypo"