What to use on a puppy for fleas?

First give your dog a good flea bath using flea shampoo. Then afterwards use one of those once a month flea medications such as Frontline Plus or Advantage II. It is a once a month flea medication that will prevent fleas & ticks from getting on him or her for a month. You apply it topically. You should also put your dog on a once a month heartworm preventative, but your Veterinarian would need to test your dog for the heartworms first to make sure he or she is negative for them before beginning the once a month heatworm preventative. It is a simple blood test.