Thankfully after a very scary week before we went away Gus is back to his old self. He was very sick and had to have blood tests which showed nothing conclusive, but he was off his food ( very unusual for him) and had no energy or interest in anything. I was so scared about having to leave him but Nicola, our wonderful vet, offered to keep him there while we were away. His appetite had started to return before we left and we returned home to a much happier cat who is right back to his wonderful self.
Whew! Can do with out that kind of drama.