Hi, I have a female cat 10 years old. My husband and I have been noticing she's getting skinnier over the last year or so. She still looks healthy from the front half but the back half is where we're seeing the thinness. Can't feel ribs, but you can feel the back half of her backbone. She seems happy and still cuddly as always. Is this an age thing or should we have her taken in to be looked at?