It took me awhile, but the story finally streamlined in my head yesterday.
Stray dogs and cats are common around Moscow. We went on dacha and here is person feeding stray dog:
Some feed them, some hate them, but most are just ignoring them...
On weekend I went to see the mother-in-law place were we lived for years. It was her, her mother and my wife. Plus, one dog and one cat. By the time we left to Canada it was two kids, three adults and two dogs, one cat. One dog was rescued from the street. And cat was saved from the basement hole at the place we used to live entrance.
So, I came to see this place. Just beside the entrance and under windows of ex-apartment I meet this person and his dog.
He was getting older, moving less and once he got blood clot in his leg, he could walk even less. But he decided to rescue this stray dog from his dacha place and because he has to walk with her outside, his leg fully recovered.