We are often asked "How long do I need to treat for fleas?" My answer is however long you don't want them to come back. Honestly, the first month that you don't apply treatment/preventative is the first month that you could be inviting fleas back into your home. You must use a quality product such as Frontline or Advantage/Advantix/Advantage Multi. Many grocery store brands are dangerous and ineffective.
Unless your pet lives completely in the house, never goes outside to potty, never goes on a walk, you don't have neighbors with any pets, you never have stray dogs or cats anywhere near your property, your pets are at risk for contaminating your house with fleas. If you have or have had an existing infestation winter is no help. We turn on our furnaces and humidifiers and make our homes Florida for fleas.
In a typical room, only 5% of the fleas will be found on pets. 10% will be flea cocoons in the carpets, 35% flea maggots and 50% flea eggs again in the carpets. Female fleas lay up to 50 eggs per day that turn in to maggot-like larvae. The larvae then develop into a cocoon. They wait for a host to start their life and suck blood. When something warm moves past the pupae, they unzip the cocoon and jump on the animal or human body. No chemical can kill the flea while in the cocoon stage (fleas can be dormant for years in the cocoon if not stimulated to hatch. This is why you can move into a new home and boom have fleas!).
If you have seen fleas on your pets it is advisable to treat at least 4 months to get your flea situation under control. You may still see adult fleas- they have to come in contact with the medication to die. The medication will reduce the infestation. Remember that the topical will be killing adults, eggs, and flea maggots, but not touching the cocoons. If you stop applying flea control while there are unhatched cocoons in your house your flea problem will come right back and it will appear that medication did not work. You must also treat every pet that is within the household- an untreated pet is a fertile meal to a flea.
So bottom line: How many months do you need to treat for fleas? How many months do you want to be protected against fleas?
