I also have 2 shepherd mix dogs, Sara and Chase, who are 13 1/2 and 14 years old respectively. Today I saw an article about the correct way to calculate dogs years. I do have a t-shirt that says "In Dog years, I'm dead" so this topic is of interest to me. Apparently the old saw that a dog year is seven human years is incorrect. So using another website, I calculated Chase's and Sara's ages. Chase is 88 and Sara (through interpolation) is 85. My mother in law has anthropomorphized Sara's failure to eat some days as "an old lady forgetting where her bowl is". Unfortunately, Sara does not forget where her bowl is as far as I can tell. She has recently learned the new trick (again demolishing an old saw) of tipping over the trash can in the kitchen and eating out of the trash. I think she is just full.
Chase and Sara have all sorts of illnesses. Sara has these growths that the vet thinks are cancer. Chase has discs problems in his back that make it hard for him to use his rear hind legs. But there are days when both of them scamper across the yard like they were puppies. The equivalent of the bounce house slide, I suppose.