
They become such an integral part of our lives. I have my old boys half Sister and like you are going through with Sam, she missed him terribly. They were partners in crime. She stopped eating and definitely went into mourning.
Fully understand about her knowing you were going out before you did, I had the same. My boy lived for his food and we used to say that we never needed a clock when it came to food times, he would always start his Sister off. When I went out and came back, even though we had another dog, the house just didn't feel or smell the same.
Its easy to say stay strong but sometimes we need to let it all out and just when we think we are coming through the other side, something trivial will happen and then the pain starts again. It is early days, in time you will start to smile at the memories again. Until then, take care. xx