Same here.
My mum had to have one of her dogs put down on monday. Bedlington / terrier cross that she had for almost 18 years. Her other dog, a whippet / terrier cross, is not very happy at the moment either, moping about looking in all the places the bedlington used to sleep etc.
The only real downer to having pets is that for the majority, we will outlive our pets. Having to do what sometimes needs to be done is hard.