If you could take some to the vet and get Revolution for all of them, that would probably be best and easiest, not easy, just easiest. Otherwise, I would probably try mixing strongid into canned food and hope that they eat enough, about 2 cc per kitty. Strongid is OTC and found at most feed stores. You can give it directly into the mouth, if they won’t claw you up. Of all the oral wormers, it’s the only one that doesn’t taste foul(guess how I know). It won’t kill everything, but it would be a starting place. Getting a fresh fecal would be best, so you know what you are trying to kill.
If you already feed some canned food, do you add diatomatious earth to their canned food? That would be a good idea going forward.
My cats always get thinner in this heat, so you also want to evaluate hair quality. Do they seem dry and patchy, or thin coated? Are they dull?
