whenever we take mickey out to do his "potty" he'll pee/poop and then we'de play for awhile. i've noticed sometimes he'll be running and every so often, lift his leg up a little and limps a bit. ( i don't know if limp is the right word) then it will touch back to the floor. it's as if the snow if cold on his paws (well, obviously). i take him inside after that, but i'm wondering if it is anything to worry about? thanks!