"Poyarkov has studied the dogs, which number about 35,000, for the last 30 years. Over that time, he observed the stray dog population lose the spotted coats, wagging tails, and friendliness that separate dogs from wolves, while at the same time evolving social structures and behaviors optimized to four ecological niches occupied by what Poyarkov calls guard dogs, scavengers, wild dogs, and beggars."
I bet they moved to Moscow from Chernobyl. I know they chased my butt all over the place there in Modern Warfare..
Perhaps zombie dogs are the next big threat.