last time my house was quite badly infected, so i sprayed about twice a month for the first few times, then things got better and it became once a month thing...then every half a year..now i dont have the problem already, i stop spryaing altogether..
if the dog goes into your house, then i suggest you spray indoors too...but if they r always outdoors, then you might not need to. But remember to let the area dry off first before you let the dogs near...cos its poisonous after all.. ... u can spray your garden too... fleas like to infest there also..and the at dark corners...