Spot On Flea and Tick Treatment

Written by:

PetMD Editorial
Published: March 27, 2015

What It Is

Spot-ons are insecticides that come in a small tube of liquid. The product is applied directly to the skin, usually over the shoulder blades or down the back.

Active Ingredients

Many, depending on the brand. Common active ingredients include: deltamethrin, dinotefuran, fipronil, imidacloprid, indoxacarb, permethrin, pyriproxifen, and selamectin.

How it Works

Spot-ons contain ingredients that are neurotoxins specific to adult parasites. Some products also contain ingredients to prevent larvae from developing. The oily liquid in which the medication is dissolved helps spread the product over the surface of the skin to the sebaceous glands. May kill as well as repel parasites.

How to Administer

Part the fur over the area where the treatment will be administered so it is applied directly to the skin. Make sure to follow instructions as to where the product should be given. Make sure the entire volume is squeezed out of the tube, as most of these treatments contain different volumes depending on the weight of the pet.

How Often to Administer

Most are administered once a month, though some products are safe to administer more frequently. Check with your veterinarian if the product seems to wear off towards the end of the month.


Do not bathe immediately before or after administering the treatment as this may decrease its efficacy. Keep children and other pets away from the pet until the product is completely dry. Make sure you use the correct dosage for your pet’s weight. Do not give any product labeled for dogs only to cats, as permethrin-containing products may be associated with toxicity in felines.

Product examples

Fleas: Advantage, Cheristin

Fleas and Ticks: Activyl, Advantix, Frontline, Only Natural Pet, Parastar, Revolution, Vectra.

Image: Antonio Gravante / via Shutterstock