I use Frontline spray on my cat and occasionally on my dogs. I prefer to use topical products to oral products for flea prevention. I use a smaller dose and keep a log on my calendar in case if I want to give more during the month. Are you able to treat your yard, car, and house to reduce the number of fleas that might get on your pets? After you get it under control then the herbals can be valuable. If your pets are scratching because of flea allergy DERMA-IONX can help reduce the allergy symptoms. A good way to check if there are any fleas on your pet is to bathe with DEFENDEX shampoo. It contains Neem as well homeopathics. You will see the fleas in the rinse water as they go down the drain.
Please let us know if you have any other questions and to let us know how you are you doing.