Summarize this article in one sentence.
You can purchase Frontline at a pet store or your vet's office. You also may be able to get Frontline at some drug stores, like Walgreens. It's a good idea to buy Frontline from a vet, however, as a veterinarian can a make sure you get the right product. Frontline makes flea and tick treatments for dogs as well as cats. Make sure you use the medication designed for your pet. The dosages are sold according to the weight of the pet. Check the weight recommendations on the package and get a dosage appropriate for your pet's weight. Frontline comes with several small plastic applicators. They look something like little bottles. Each applicator contains a single dose of Frontline. There are perforated lines between each applicator. You can separate the applicators by tearing or cutting along the perforated line. Be careful when separating the applicators. You want to make sure you do not tear an applicator and spill a dosage of Frontline. Each applicator has a small tip that you can easily snap off. You must snap off the tip prior to applying Frontline to your dog or cat. Make sure to do this away from your face to avoid getting the chemicals in your eyes. If the tip does not come off easily, you can use scissors to cut it off. You should apply Frontline on your pet's back, directly between your pet's shoulders. Frontline is safe to use on a pet's skin, but should not be ingested by the pet. Your pet will be unable to reach this area, preventing them from licking Frontline off. Part your pet's fur so you can see its skin. This is very important. To work effectively, Frontline must be absorbed into your pet's skin. It must make direct contact with the skin, and not the fur, to do so. Place the tip of the applicator onto your pet's skin. Squeeze the vial and empty all of the liquid onto your pet's skin. Try to avoid getting any liquid on your pet's hair.

Summary:
Buy the correct type of Frontline. Remove the applicators. Snap off the opening of the applicator. Find a spot on your pet's back. Apply the Frontline to your pet's skin.