How often should I use Effipro spot on flea treatment? Your pet will need a regular flea treatment to ensure any infestation does not return.  Write monthly for cat or every other month for dogs reminders on your calendar so that you don’t forget. Fleas are extremely persistent and tough.  The flea life cycle allows for flea pupae to lie dormant in carpets, blankets, upholstery etc for up to a year.  If you have animals in the house there is a strong possibility that you will have to treat your home too by using an environmental flea spray. We can help by providing a good environmental flea spray such as Indorex to do this.