In spite of the manufacturers instructions, PLEASE do not use any product with PYRETHRINS to control fleas on cats. Cats absorb it through their skin and it is TOXIC TO FELINES OF ANY AGE. We nearly lost a family member due to lethal misinformation.
My sister Lisa's cat has 4 kittens. At 6 wks., she dipped them in a dilute solution of Ectokyl, which is marketed as a flea control shampoo for dogs, cats, puppies and kittens. One of the males was not as active as the others and wasn't eating very well (they are just starting solid foods, but still nursing).She thought the fleas were to blame, so she treated him again according to the instructions on the bottle (lather animal, leave on for 5 minutes, rinse).
We brought him to the vet the next day because he wasn't able to walk, he just sort of wobbled and crawled. His PCV level was 4 - it should have been 40. For those fortunately unfamiliar with this, PCVs are a measure of the red blood cell activity, which of course affects oxygen levels systemically. He evidenced some signs of neurological damage (unsteady on his paws, head tilted) and would not have survived without a blood transfusion.
After 24 hours, his PCVs were up to 20, his head was much less tilted and he was steadier in motion (not 100%, but better). The vet was very optimistic about his chances for a complete or very nearly complete recovery, based on his age and improvement. We have another appointment on Wednesday the 20th, so I'll keep you posted.
Our vet was very disgusted with the fact that she has had cats who died from pyrethrin exposure with live fleas still on them. I just want to make sure that this info is disseminated as widely and quickly as possible, to save anyone else from needless suffering - feline or human.
Please don't assume that someone who is experienced with cats knows this - we have had cats all our lives. We (stupidly) assumed that manufacturers of pet care products were at least bound by truth in advertising laws if not more stringent requirements, and nearly killed our cats.