We personally do not use the topical flea control. We prefer an organic approach to flea control and treat our yard with Diatomaceous Earth. D.E. is made up from fossils of freshwater organisms and crushed to a fine powder. D.E. is deadly to any insect or larvae that travels thru it by scratching the insect's outer shell and causing dehydration. It is completely harmless to humans, animals, fish, birds or in food. Many livestock breeders add it the their animals feed to prevent ants, worms etc. from invading it. It can be purchased at feed stores or thru Revival Animal Health. Be sure that it is food grade D.E. and not the kind used for swimming pools. If you live in an area where fleas and ticks are terrible, then you may have to use one of the topical flea controls, be sure you purchase from the veternarian and use the appriate amount for your dog's weight---think about it, don't use the amount for a 10 lb. dog if you Yorkshire Terrier or Maltese only  weighs only 2 lbs!! Pay attention to your Yorkie/Maltese,  if your dog experiences any stool changes, tummy upsets, etc. within a couple of weeks of using one of these products----consider a homeopathic or organic approach.