Yes, i've brought in cats with fleas, even when I was being very carefull not to. Upsetting the cat was the least of my worries. You want to get rid of those fleas fast, before you end up having the flea-bomb the house! You start with treating all the cats with topical flea and tick treatments like Advantage or Frontline. Buy the best you can afford; this is a care of you get what you pay for, and the higher priced treatments have the safer and more effective ingredients. But never, NEVER use flea treatment for dogs on a cat!!! There are some things safe for dogs that are toxic for cats. And read the label! My problems with fleas came when I took in kittens that were too young for topical flea treatments. Next step is to vacume your entire house repetedly, including the furniture. Fleas feed on warm-blooded mammels, but they live in the carpeting and upholstry. Wash all the bedding too. If the fleas still take up residence in the house, then you will need to fumigate. Go to a hardware or garden store and get what we call "flea-bombs". Cover all the dishes or wash them all again afterward. Remove the pets food and water dishes. Cover or protect all food. Turn off pilot lights. Cover fish tanks. Remove ALL pets from the house!!!. Set off the flea bombs and get out! Spend about the next four hours out of the house with your pets, then come back and open windows and turn on fans to air out the house. Scrub off food prep surfaces and wash the bedding. THEN bring your pets back in. If you seem to get fleas frequently and you have pets that go outside, you might need to treat your whole yard for fleas so your pet doesn't keep getting re-infested. If I'm going to bring in a cat that might be infested or kittens that are too young to treat, I bathe them to kill the fleas right away, since topical treatments usually take twelve to twenty four hours to act, giving time for fleas to jump-ship and infest your house.
Obviously, this all is a royal pain-in-the-neck! So this is why you should ALWAYS very carefully check any animal you plan to bring into your house. Look for little black specks in their fur, that turn red when you get them wet. This is flea-poop containing the blood they suck. That is your best indication of fleas.
