We have a two cat household which includes a 16 year old skinny, spayed female and a 6 year old porky, spayed female. The older cat is a grazer, the younger eats everything in sight.
The old cat is healthy, but has gradually gone from about 7 1/2 lbs (her average adult weight) to 6 lbs. over the last 3 years. I am currently feeding her wet cat food every time she asks, about 9/10 times a day. She eats pretty much all I put down for her, leaving a crumb or two for "porky". Even with this feeding on demand, she continues to lose weight.
Is there a high calorie cat food that would be advisable for an older cat? Or any other advice for me to help her maintain, or even gain some weight?