Many pet owners ask if they can use two or more flea and tick products simultaneously on their pet. We generally recommend using only one flea and tick control product on the pet at a time. In the past, more than one product was often needed if you wanted to kill both the adult and developing fleas but today, many of the newer flea and tick products that kill adult fleas and ticks also prevent flea eggs and larvae from developing, so only one product is needed.
When you may want to use two products together
There are some situations in which using two products together on the pet may be more effective. An example would be tick prevention in a heavily tick-infested area. In such cases, we might recommend using two products - such as a topical and a tick collar - if they are administered differently and have different mechanisms of action.
We do NOT recommend using more than two flea and tick topical products together on a pet.
So, which products can be used together?
Here are some guidelines on which flea and tick products cannot be used with others, those that can, and those to use with caution on the advice of your veterinarian. These guidelines should be safe for most pets, however, every animal is different and two animals can react very differently to the same product.
If you have any questions, or if a pet is old, sick, being used for breeding, pregnant, or nursing, you should talk with your veterinarian before using any product or more than one product.
Can flea and tick products be used with heartworm preventives?
Generally any flea and tick product used to prevent or eliminate fleas and ticks alone can be used with any heartworm product used to prevent heartworm disease. Do not use a flea and tick preventive that includes a heartworm preventive (such as Revolution) along with another heartworm preventive (such as Sentinel).
Our recommendations for compatibility falls into three categories, S, those safe to be used in healthy animals with other products, N, those products that should not be used with others, and C, those that can be used together with the advice of a veterinarian. Note: Most products listed below cannot be used on cats, see Flea & Tick Control Compatibility Chart for Cats.
S- Safe to use together
In healthy animals, these products can generally be used together safely.
Sentinel® can be used with Advantage II® or K9 Advantix® products, Bravecto, Capstar®, Comfortis®, NexGard®, Fipronil-containing products¹, Preventic® Tick Collar, Pyrethrin/pyrethroid-containing products², or the Seresto® collar.
N- Not safe to use together
We do not recommend using the following products together. Products may contain similar ingredients, or there may be a risk of an interaction between them. Consult with your veterinarian if you have questions.
Advantage and K9-Advantix products should not be used with each other or the Seresto collar.
Advantage Multi should not be used with Advantage or K9 Advantix products, BioSpot Active Care, Revolution, Sentinel, Trifexis, or the Seresto collar.
Using two or more products with caution under the advice of a veterinarian
Most other flea and tick products we carry have not been approved by the manufacturers for use together, and no information on the safety of using them together is available. Using two products may be safe if the administration of products is separated by several days to weeks; however always consult your veterinarian before using two products together.
¹Fipronil containing products include Drs. Foster & Smith Fiprotrol™ Plus Flea & Tick Control for Dogs, Frontline Plus®, Fiproguard™, PetArmor® for Dogs, and Hartz First Defense for Dogs.
²Pyrethrin containing products include Bio Spot® ACTIVE CARE Environmental Flea & Tick Protection, Adams Plus Flea & Tick Protection, Bio-Groom Flea & Tick Shampoo by Bio-Derm, and Bayer Advantage® Shampoo & Spray Treatments for Dogs.
Treating the environment
Remember that in addition to treating fleas and ticks on the animal, you also need to treat the pet's environment, indoors and out. Many indoor products contain both an adulticide (permethrins and pyrethrins) and ingredients to kill the eggs and larvae (Nylar). Examples include Bayer Advantage® Household Fogger, Virbac Knockout E.S. Area Treatment, and Adams Plus Flea & Tick Spray.
When using foggers, you need to cover/seal fish tanks, and remove any birds, before using. Vacuum and wipe off counters/eating areas thoroughly after using any fogger.