Make a bowl of soapy water , comb pet with a flea comb and dunk quickly into soapy water. Repeat. I have made flea dip by using 2 table spoons of kerosene a quart of milk, and water to make a gallon. Do be careful around eyes. Let sit for 5 minutes. I followed with an oatmeal shampoo.
Dawn original blue dish washing liquid, guaranteed.
GreenerWays makes a non-toxic bug spray that you can use on your dogs, I get it on Amazon.
On my long-haired cat who is allergic to those drops, I use diatomaceous earth in a jar with lots of holes poked in the lid, then I sprinkle and brush on her fur being careful not to get in her eyes, nose or mouth. Buy the food-grade DE at your pet store. Then I get her baths and a blow dry frequently.