Our mild winter has resulted in major nasty bugs. Our dogs have fleas. We have NEVER had fleas i found a tick on dd's blanket at a friends house and dh fo7nd one on him after being outside.
My mother's dog got fleas a few summers back. It was months. MONTHS before we got them out of the house completely. We had flea bitten ankles when we stayed over. The cat got them. It was ridiculous. And I kid you not my mother vacuums twice a day, every day.
Frontline or advantage. If the infestation is bad on the dogs talk to your vet about capstar for quick removal then back to a preventative. Borax on the carpets and vacuum your heart out.