When it comes spring the dogs smell all sorts of things that we don't. When we know the snow has gone for good we use a disinfectant on all our walkways, decks etc that is non toxic to the dogs. I can't even remember the name but I get it from a lady that does the dog shows.
I also know Canadian Tire used to sell something that you can put on your hose through your fertilizer bottle that does the same thing. It's not necessary - just something we do. I like the fresh clean of 'clean' what can I say. :-)
Do you ever wonder what your dogs can smell that you don't? Read this.