Hi, years ago my 2 cats were infested with fleas and passed them on to the dog. We washed the cats with insecticidal wash(not normally recommended), combed and searched for every flea but still no luck wiping them out. So we used the "flea bombs" in the house -- these are NOT an insecticide -- they spray a growth hormone which stops flea larvae from growing into adult fleas and so stop the reproductive cycle. This was a great success -- we repeated it once a year while the cats were still alive and had no more problems.