Do we need more flea poison?

Shelter cat had fleas upon arrival to the shelter. He was given 2 applications (once each month) at the shelter. He was brought home and found to have a tapeworm presumably caused by fleas. He was promptly dewormed. I then took him into the vet for shots etc. At that time he was given 1 more application of flea control medicine.

The next month is here to give him another application if I were to continue. I don't see any signs of fleas. He has been dewormed too. He is also an indoor cat.

 I don't want to subject him to poison again if it is not necessary. The vet tried selling me a 6 month supply of their flea prevention program which I declined.

Do I need to continue flea control (with store bought poison) for a fourth month given the circumstances?

There are lots of different flea medications out there, and their quality and safety varies a lot!

It's not always the case that the vet-provided and more expensive option is better for your kitty (take most prescription foods for example), but when it comes to flea medication, it is. Most flea medications that you can buy at a pet store for cheaper prices are going to be much more risky for your cat. Especially avoid any ingredients from the pyrethrin family.

The prescription brands (Revolution, Advantage, Frontline) are much, MUCH safer for cats. They rarely result in dangerous side effects. Occasionally a cat will have a topical reaction to some of the inactive ingredients it their skin is sensitive, which can be uncomfortable and a reason to try another form of medication but it is not dangerous. My personal favorite is Revolution, because it protects against heartworm as well, which can't be cured once a cat has it. The active ingredient that kills the invertebrate parasites cannot pass through the blood brain barrier in a mammal, so the cat is not affected by it at all.

Having a cat on a monthly flea, tick and mosquito medication if you can is probably best, because many diseases ranging from mild to severe can be transmitted by these parasites. It's especially important if your cat spends time outside, during the summer months, and if you live in a warm and buggy climate.

thanks for the reply, I really appreciate it.

Do you think an initial 3 applications of meds (in this case 2x of Sentry from shelter and 1x revolution from vet) would have cured the initial case of fleas he had? (giving me a clean slate per say to decide at this point if I want to continue.)

If I don't visually see fleas and the animal isn't itching is it safe to assume its gone?

Have you tried using a flea comb? You said visual inspection, but not sure if you meant just looking at the cat or going through with a flea comb.

A flea comb should find any fleas that aren't easily visible. Dunking it in soapy water after you've combed it through their fur kills off the fleas. I just bought a cat flea comb at walmart for two dollars, so you should be able to find one cheap. If you don't find any fleas with the comb, I think it'd be pretty safe to say the fleas are gone. My vet usually checks for them with a flea comb, too.