Pickles is old

So Mr Pickles is sick. A weird kind of sick because he's not eating. Anything else I would think, "It's just something mild", but when he's not eating or begging for people food, something must be wrong. We adopted him about 8 months ago, and we were told he was 5. I also was told that he was just given a checkup by the previous owners at a Vet close to where I live. So today when I decided to take him in to a vet, I decided to try them first. I got luck and they were able to match him with his old records. His original name was Shea and although I'd never heard that as a name for a pet, ours was #4. I took him in and they told me that he was 8 years, 8 months old. Wow my kitty went from a middle age to senior citizen in a 2 minute conversation. We can change how we deal with him but Brick, our 15 lb kitten, doesn't understand he's dealing with an old grumpy bastard. Although now that I think about it, he probably does and that's why he's always riding Pickles through the house...