Help! My cat is not eating much anymore
So I have a 13.5 year old female cat who I've had for almost her whole life. She has always been extremely picky, will only eat dry food and specifically purina fancy feast. She goes to the vet regularly and they have always said that as long as she's eating something then purina is fine. But recently (the past two weeks) she has been gradually eating and drinking less. She has always been very healthy, so when this happened and did not subside I took her to the vet. They said that everything looked good during the physical examination. They did blood work as well which came back fine. I have tried giving her different brands of dry and wet food with no success. The only thing she will even pick at is greenies cat treats.
I know she's old and it could just be related to that but it's starting to worry me because this is progressing quickly. Any advice on what I can feed her or do for her would be appreciated.
Also I am fairly new to reddit and have never posted before so please keep that in mind!