Remove the dog's collarApply as a spot between your dog's shoulder blades in 1 area that can't be lickedAvoid touching the wet application spotWait 24 hours to allow solution to dry before bathing or letting your dog swimGive each of your dogs its own complete doseThe flea life cycle—break it, or else.Flea infestations start with just 2 fleas laying hundreds of flea eggs within a matter of days.1 So preventing an infestation involves more than killing just adult fleas.