Caution: Do not use products formulated for dogs or any product containing permethrins on cats.
Topical Flea Products
These chemicals are packaged in a disposable ampoule. The ampoule is broken open and the chemicals applied to a small area of your cat's back. Some brands kill ticks as well as fleas. Adult fleas are killed quickly and larvae and eggs will not hatch. Topicals are used monthly.
Caution: Wash hands thoroughly if you come in contact with the liquid.
Oral Medications
Given by mouth once a month, the most popular oral flea preparation is a growth regulator which does not kill adult fleas. A separate product is needed to kill adults. Because these products are given orally, there is no toxic residue on your cat's fur.
Getting rid of cat fleas for good requires that you treat the environment, too. Sprays can be used indoors and outdoors to kill adult fleas and larvae. Vacuum all living areas thoroughly, concentrating on areas frequented by your cat.
Complete eradication of fleas may take several weeks, depending upon the severity of your infestation, but your cat will appreciate your efforts.