Everything in this thread is so very familiar. I have been dogless for six years and it weighs on me. Usually had two or more, big and small. The small ones seem to make up for their size by having outsized personalities. The blind one I had was the sweetest of all. I keep their collars.
I, too, have long wondered about why the death of a beloved dog is such a blow, emotionally, spiritually. Yes -- it does hurt in a way that the death of a relative or even a parent does not. They have been humans' friends and boon companions for 30,000 years or more. I believe the attraction may have become genetic.
And here is proof of a decent man. (For you young pups out there, he's Lyndon Johnson.) Do you sing with your dogs? I did.