Talk to your vet and see what advice they have to give.
Where we live, fleas are not too much of a problem. Our vet recommends only giving treatment as and when necessary, as one of our kittens, Conor, experienced side effects with the medication (nothing serious - but enough to scare us and her) and Steve (who is a nervous cat to begin with) got really, really stressed out by the application. I have a friend with three cats who only applies treatment before they go into boarding (required) because one of her cats experiences quite serious side effects (very scary - I was there the last time she had to apply). Since we have treated, we haven't had to re-treat. Our vet thinks our (former feral) kittens got the fleas from when they lived on the street and since they are indoor cats, he told us to monitor the situation before we went about treating them all the time. I don't know - all situations are obviously different, but in all my years as a pet owner (mainly dogs), I have never had to do consistent treatment, and neither has my husband (mainly cats). Talk to your vet - they will know what your environment is like and can advise you!
Where we live, fleas are not too much of a problem. Our vet recommends only giving treatment as and when necessary, as one of our kittens, Conor, experienced side effects with the medication (nothing serious - but enough to scare us and her) and Steve (who is a nervous cat to begin with) got really, really stressed out by the application. I have a friend with three cats who only applies treatment before they go into boarding (required) because one of her cats experiences quite serious side effects (very scary - I was there the last time she had to apply). Since we have treated, we haven't had to re-treat. Our vet thinks our (former feral) kittens got the fleas from when they lived on the street and since they are indoor cats, he told us to monitor the situation before we went about treating them all the time. I don't know - all situations are obviously different, but in all my years as a pet owner (mainly dogs), I have never had to do consistent treatment, and neither has my husband (mainly cats). Talk to your vet - they will know what your environment is like and can advise you!