Two popular flea medications are Bayer's Advantage and Merial's Frontline. The active ingredient in Advantage in imidacloprid, while Frontline uses fipronil. Both Frontline and Advantage can be purchased from your veterinarian. Prices vary depending on the size of your pet and the number of doses in the package.
Both Advantage and Frontline are applied topically. Frontline is placed only between your pet's shoulder blades, as is Advantage for cats and dogs weighing less than 21 pounds. Bayer recommends you break up the Advantage dose into three or four applications along the spine of a dog that weighs more than 21 pounds. Application is done once a month, and dosages are based on your pet's weight.
Both products are marketed as being waterproof, so you shouldn't have to reapply after giving your pet a bath.
Both Advantage and Frontline claim to kill most or all of the fleas on your pet within 12 hours of application. Advantage's website at PetParents.com claims the medication begins killing fleas within three to five minutes. The Frontline website does not say how soon the fleas begin dying, only that all should be dead within 12 hours.
You can begin using Advantage when a puppy is 7 weeks old or Frontline when your dog is 8 weeks old. With both products, a kitten needs to be at least 8 weeks old. Frontline can be used on males at stud, pregnant females and lactating pets.
You can use Frontline to kill adult fleas and ticks on your pets, but Advantage works only on fleas. Advantage, however, does kill flea larvae as well as adult fleas. With either product the fleas (or ticks, if applicable) do not have to bite to be affected by the active ingredients in the medication.
What They Do
Advantage and Frontline break the flea's life cycle by killing adult fleas before they have a chance to lay eggs on your pet.Frontline gets absorbed into your pet's oil glands so that every time your pet produces skin oils, the Frontline medication is produced on the skin. The imidacloprid in Advantage paralyzes fleas by getting into their nervous systems, which kills them. The solution spreads over the top of your pet's skin.
Some pets may get skin irritations after the application of Frontline or Advantage. If your pet licks the solution after it's on his hair, he may start to drool excessively.