If you walk your dog along pavements, consider washing your dogs paws when you return home to remove any such substances, or splashes of spilt anti-freeze which they may have stepped in.
Update on the dog poo wormery - it has arrived (thank you Jill!) and will be posted here next week. I'm definitely going to save up for one - it sounds like such a good idea. But more about it all next Friday - in the meantime wrap up warm!