A man petting an Weimaraner in the yard with a red sign of Bayer K9 Advantix® II in front.

Kills and repels through contact — no biting required.

Fleas, ticks and mosquitoes want to bite your dog. These bites can cause pain, discomfort and possibly deadly disease.

  • Tick bites can transmit Lyme disease and Rocky Mountain spotted fever.
  • Flea bites can cause flea allergy dermatitis (FAD), an allergic reaction that can cause scratching, hair loss and rashes. If swallowed, an infected flea can also transmit tapeworms.
  • Mosquito bites can transmit deadly diseases like heartworm* and West Nile virus.

But let’s be honest — simply avoiding parasites isn’t possible. That’s where K9 Advantix® II for dogs comes in. K9 Advantix® II is a monthly topical treatment that protects your dog by killing and repelling fleas, ticks and mosquitoes.

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Protection from fleas, ticks and mosquitoes

Veterinarian-recommended K9 Advantix® II kills fleas, ticks, mosquitoes and lice, and repels biting flies. And because it kills through contact, pests don’t have to bite your dog to die.

K9 Advantix® II kills and repels fleas FLEAS
K9 Advantix® II kills and repels ticks TICKS
K9 Advantix® II kills and repels mosquitoes MOSQUITOES
K9 Advantix® II kills chewing lice CHEWING LICE
K9 Advantix® II repels biting flies BITING FLIES

Product Label Application & Safety Information
K9 Advantix® II for extra large dog packaging
  • K9 Advantix® II for dogs kills through contact with no biting required.
A chart showing K9 Advantix® II effectively kills and repels fleas, ticks, mosquitoes, compared to other brands.

  • Based on label claims.

    K9 Advantix are registered trademarks of Bayer. Frontline and NexGard are registered trademarks of Boehringer Ingelheim Animal Health. Bravecto is a registered trademark of Intervet, Inc. dba Merck Animal Health. PetArmor is a registered trademark of Velcera, Inc.

A Labrador taking food from owner’s hand at a park at sunset.

The more you know, the better. For both you and your dog.

  • Fleas, ticks and mosquitoes can cause diseases that may compromise your dog’s health. Learn about parasite prevention and the ways you can help your dog.

    Mosquito Diseases in DogsKnow the Facts >

    Flea Diseases in Dogs Know the Risks >

    Tick diseases in Dogs: It May Only Take One BiteLearn More >

Flea, tick and mosquito treatment for your dog
— the smart way.

  • Why are flea, tick and mosquito bites dangerous for your dog?


    Bites can cause more than just discomfort. 0:40

  • How long does it take for K9 Advantix® II to work?


    Kill fleas, ticks and mosquitoes through contact— no biting required. 0:38

A veteran in uniform petting his dog in front of sign saying “K9s For Warriors”.

We're proud to partner with K9s For Warriors.

  • K9s For Warriors pairs trained therapy dogs with America’s healing heroes. We are proud to support these canines and their recovering humans.


    Do not use on cats.

K9 Advantix is a registered trademark of Bayer.