Suggestions on food?

OMG, my cat has been eating Friskies for a very long time. She is female, older cat (15 yrs). Lately she has developed a few problems: vomiting, diarrhea, itching, sneezing, loss of hair in the tail!  I guess is the food.  She has been in and out of the vet. Definately taken her off this food.  I will try Iams or Science diet.  Suggestions on any of these?  Thanks to all

I would suggest a grain-free canned food. Something like Merrick  or Wellness Core. The Vet doesn't know the cause of the problems?

Seems odd that after 15 years of eating the same food, to then develop issues?!

Did anything else in the house change? New soaps being used, new laundry detergent, new household plants?!

It could be anything really. But the food might be something to consider as well. Grain free is a very popular diet. If you venture into the article section and read up on food choices, it'll help you make a more confident decision. If you're looking for opinions, then I would suggest to find other brands besides Iams and Science Diet as they have a lot of corn and fillers. Just my opinion though!

I know it sounds weird but it is possible for cats to suddenly develop allergies to something that they have been eating their whole lives.  I'm actually in the process of trying to find out what is making my cat so itchy.  

Yes it is that is why rotation is key, it prevents over exposure to same brands and protein sources.

Where you feeding her dry, wet or combo of friskies?