We are in the same boat as you my old girl is 18 1/2 and she does not do much at all now, we took her to the vets about a month ago as she looked so sad, I thought they would put her down but after an examination they told me that she was in good condition even though i have to clip her back end as she will not wash, she has artheritus in her hind quaters and gave me some metacam for cats ( antiinflamitary liquid form which helped loads and prescribed some aktivate for cats it stimulates there brain for aging cats, she is loads better now, but i am dredding the cold winter months.