1. It’s similar to when other people get close to death: they stop eating, or eating as much, and tend to spend more time sleeping. Sometimes there’s an abrupt change in behavior, like after a fall, and sometimes it is gradual. I’ve also noticed that people are sometimes more agitated, like they can’t “sit still” and always want to try and go somewhere else.
2. I am no vet, but I believe it’s similar. The problem, of course, is that dogs don’t speak the way that we speak, so it’s hard to know if there’s much of a memory issue other than observation.