Walking lab/others in very cold weather

Question
Hello, I have three dogs a labrador retreiver jack russell terrier and boston terrier, I walk them all once a day in the morning, lately the temprature has droped and will only get colder today it is -13 C. without the windchill which would make it around -19 or so... is it ok to walk my lab when its this cold? will it harm her at all..will she be cold during the walk? she is three this december.

also do you think tis wise to walk teh jack russell terrier in this weather...trying to tell him he cant go doesnt go over so well, my boston terrier starting to lift her paw after half a block yesterday and needed to be carried home...the small dogs have coats but no boots yet...I was trying to find so yesterday with no luck of finding the boston terriers size. thank you for your time.

Answer
Be sure they have plenty of water.  Watch them and see how they are doing.  If they are prancing along enjoying themselves, keep it up.  dogs eem to like cold and snow.  If the tails and ears start to droop, and they are lagging or pulling back toward the house, better quit for  the day.