Purnia cat food question

This is just a general question. I was wondering if anyone here knows what the difference in quality is between the Purnia cat food sold in vet clinics and the Purnia sold in grocery stores.

A little over a year ago my local vet clinic switched from Science Diet to Purnia, and they sell only one brand of food at a time. When the change was made I was told that some cats thrived on the Purnia and some didn't. I knew Snowball didn't have a lot of time left, but I can't halp but wonder if the Purnia didn't help accerlate that final decline in his health.

What kind of purina was it?
I use purina N/F and have used purina urinary.
My vet sells science diet but they order purina and roya canin also if I want it.

It was Purnia NF.

I used that with Stripe when she had Crf and Coco has that and K/D.
Coco likes the K/D better but stripe hated it.
I can ask in the Crf group and see if what they think.
I am glad my vet lets me have a choice of kidney food.

Snowball was more willing to eat the Purnia NF than he was the Science Diet kd. And at first I thought he was thriving because of the change, now I'm not sure if he was or not.

Another reason I'm asking about Purnia is because I'm hoping to get another cat fairly soon. (fingers crossed) I'm also wondering if Purnia is a good choice for cats in general.

NO Rx is a good idea for a healthy cat to eat ... some are "acceptable " for a healthy cat to eat ... IMHO the purina does seem to go over better than the sd

Both of my renal failure cats eat Purina NF canned food, and they love it. Actually, they are positively thriving. Cleo has been doing so well on the Purina NF, that she could actually benefit by losing a pound or two! They prefer the Hills k/d dry over the Purina NF dry. I only give dry food (about a table spoon/day) as a treat, because renal failure kittys need the extra moisture provided by canned food, for their remaining kidney tissue to function optimally.