Thanks to everyone for your feedback.

In case anyone is curious or hasn't guessed yet, Formula A is Innova Reduced Fat, and Formula B is California Natural Chicken and Brown Rice. Both made by Natura, which is one of the few companies I trust the most (or should I say, distrust the least) right now. All the numbers I used for comparison came off the Natura website.

Anyway, I've been thinking through the pros and cons of switching, and for me it basically comes back to one thing: what I'm doing now isn't working. So it can't hurt to give the California Natural a try. I'll pick up a bag this week and see how she does with it - if she balloons up in size, I'll know it's not working. 

I've started another thread to cover KD's issues with canned food. That will be the next challenge.

Just wanted to mention in case some aren't aware of this.  If you have a better pet food store in your area or a natural food store or feed store, most of them have boxes of free samples you can try of dry foods rather than ordering and finding out your cat/dog doesn't like it.  Ask them if they have any samples for you.

One of my cats is 17lbs and needs to lose weight She has always been on a reduced diet and only fed 2 times a day, never free fed.  She is only 6.5 yrs old, and im so confused after reading all these posts on what to feed her.  Right now she is on Innova reduced fat dry and Innova reduced fat wet.  Im worried she will become a diabetic or her kidneys will fail after learning about the phosphorous.  I need some advice please!  I also wrote this in another thread.  She has something wrong as she is scooting after she pees,(not poops) so its not worms and the urine is a bit smelly, not sure somehow have to get the vet to take a sample of her urine without having to cage her overnight (impossible)  this is what he wants me to do.

TBOBINA-
Has your cat had bloodwork done yet?  To help with the urine sample you could add some water to her wet food.  I do this with all my cats, and I have one who recently had a UTI& kidney infection and showed early CRF in the bloodwork.  I feed this cat Natura California Nautural wet because I don't trust other companies and haven't found anything else so far.  She was eating a different food even higher in phosphorous when I noticed she was becoming sick.  Despite the phosphorous content of the california natural I decided to use it over the prescription foods and see how she does with retesting blood test levels.  I think you will have a better idea of what direction to go in with food once you have the tests done.  Good luck getting the urine done- would you be able to remove the litter box for a few hours before the visit?  I've done that along with adding water to the food and it went fine.
Lanie

I would skip the dry food completely.  I agree with the earlier posters.  You need canned, high protein (unless the cat is CRF).  I have two cats loosing weight on Wellness and EVO canned.  I tried a light dry diet for years and if I reduced the quantity they only got grumpy.  Their change is huge.  More energy, better fur. 

I saw catkins diet posted earlier so I won't repeat it (Dr Greco). 
This one is a bit techy - but also more of the same:  http://www.avma.org/publications/default.asp  (http://home.earthlink.net/~jacm2/id1.html)
I actually did a phone consultation with Dr Lisa Pearson earlier this week. 
I'm not an expert myself, but after pouring over information on the internet for the past few months, I quickly became convinced that I was actually doing my cats harm with their dry food. 

OMG...slow down. That phosphrous % sounds high for a kidney-comprimised cat. As well, yep, there's a concern about cranberries because of the acidifying effect on the urine.

I joined the online Yahoo group run out of http://felinecrf.org/ just as a learning experience and, if you have a CRF cat - or one with some kidney damage, I would strongly urge you to go through the site - especially the nutrition section - and to join the group. You will be able to watch as cases unfold, hear the symptoms, hear the directives to eliminate those symptoms - and hear back from the pet's parent.......all in real time.

One just has to be sooooo careful with a kidney-damaged cat. There can't be any: try this/try that without bordering on some peril.

Just a word to the wise. (Sorry if I've gone overboard)

hi everyone,
thanks for the suggestions and information.  I am aware that the california natural wet I'm feeding is not restricted in phosphorous as the prescription diets are.  but I made a decision to use that food for several reasons- and it's a long story, but basically I am skeptical about the foods she had been eating prior to her symptoms (she was diagnosed with UTI and had elevated BUN and creatine).  since this is off topic, I just wanted to mention that I've contributed to other forum discussions on cats with UTI and what to feed for CRF.  I feel that the foods she was eating prior to the symptoms were very high protein&phosphorous (raw food, then mainly Petguard chicken&wheatgerm wet, and then briefly EVO wet, but she also would steal some natural balance and hill's wet food from the other cats.  I still worry about contamination playing a part.  But basically since I quit using Hill's for good and don't want to give her the prescription brands, I decided to try a different food and see how she does.  Luckily she recovered really quickly, and when I have her retested next week to see what the kidney levels are, I will go from there to decide if I need to further restrict the phosphorous.  Right now she seems very well, but I do know from experience that cats can hide their illness until it's too late so I will stay on top of it.

Orange Fuzzball- thanks for the felidae suggestion.  I had the same idea at first, since it's not made at Menu which is what I would prefer, but she was stubborn about it, and I was concerned about the hard whitish chunks in it- I thought it was bone fragments but maybe it was hard cartilage?!  Not sure, and I don't want to speak badly of that company at all (one of my cats ate the dry food until I converted her to wet), but it wasn't working at the time and I had to get this cat eating well!  I'll keep it in mind though!

Lanie

The reason they don't (and you'll see it on the site) - is that Prescription Diets are just marketing tools (as you've seen - they just don't do the trick).

A wholesome diet is all the Kitty/Dog needs.  There is no need for special Diets with Gwainy stuff for kitties.  Healthy food is all they need (the closer to homemade, the better).

I wouldn't buy a Prescription Diet.  They don't need it (I know - 14 yo kitty, vast improvement after almost 9 years of Gwainy Cwap - or whenever they started dummying down the ingredients - still kicking).