You need to bomb the rooms the dog was in. That means take the cat out entirely, and be prepared to rewash all pots and pans and dishes etc. post bombing. I've also taken out my houseplants when I bombed. Otherwise, you will have flea eggs in the carpet that will hatch out in 3 weeks and continue the infestation. Take the cat and use a flea comb on it, and comb EVERYWHERE. If no fleas are found, the cat is probably OK. If fleas are found, get some feline Frontline or Advantage and apply per instructions. Oh, and you are going to have to bomb again in 3 weeks, when the eggs hatch out. You can't kill the eggs with anything I've EVER heard of - you have to wait until they hatch to kill them.