Just an update. Ruby went back to the vet for her boosters a couple weeks ago and she had gained weight in the month. The vet thought the IAMS wet cans, plus some dry each day was fine, but I'm still doing my research. I'm ready to buy more food and will likely try the Fancy Feast. But was also wondering about pet store wet food. Are they a step up from grocery store brands. And is vet bought food the best?
You can obtain much higher grades of food from pet stores than grocery stores. For instance, Wellness, Evo, Soulistic, Tiki Cat, and all raw food are at pet stores and not grocery stores. Even more food is available via mail order (see my signature for places that sell single cans). Food from the vet most often means prescription food, at least at the vets I went to. The biggest manufacturer of prescription food is Hill's Science Diet and it is not good food. Hill's tends to be full of carbs and plant proteins.
Edit: Let me qualify at bit on the Hill's statement. It tends to be poor nutritionally, but does address the specific medical condition.
Yes you will be able to buy better quality foods at the Petstore over the Grocery Store. Vet foods are usually NOT the best as they are loaded with carbohydrates and inappropriate ingredients for cats. However some vets, like the one I work for also carries EVO which is a really good food. But they still sell the Science Diet and Prescription products (GAG). Yes the prescription products are targeted towards specific disease, but you can find alternatives to pretty much all of them. I have cats with bladder issues, they eat Fancy Feast, no bladder problems for 4 years up until now. My dad had a cat with Kidney Failure, he lived 3 years on Fancy Feast and Friskies canned foods.....he wouldn't touch the vet Kidney diet.