I got a lab puppy 4 days ago. Today I noticed a flea(1) but didn't see any others. I know there have to be more either in the house or on the dog but I haven't seen any. I also have 2 other dogs and I know they don't have fleas so I have been keeping them separated. What should I do to be sure to prevent any chance of a flea outbreak? Should I bathe her with dawn dish soap? Do I need too treat the whole house?