K9 Advantix II (Imidacloprid/Permethrin/Pyriproxyfen Topical) for Dogs

Medically Reviewed by Joshua Conrad, PharmD on October 22, 2024
5 min read

K9 Advantix II (other brand names: Activate II, Provecta Advanced) is a combination medicine for treatment of fleas, ticks, mosquitoes, biting flies, and chewing lice in dogs and puppies. It contains the active ingredients imidacloprid, permethrin, and pyriproxyfen. 

Imidacloprid is classified as a neonicotinoid insecticide that controls fleas and lice. Permethrin is classified as a synthetic neurotoxic pyrethroid insecticide that controls fleas, ticks, lice, and some mites. Permethrin also repels flies, gnats, and mosquitoes. Pyriproxyfen is classified as an insect growth regulator that controls flea eggs and flea larvae. The three active ingredients are combined into a topical liquid that is applied to the dog’s back every 30 days.

Imidacloprid, permethrin, and pyriproxyfen are approved by the Environmental Protection Agency for use in dogs and puppies. Dogs should be at least 7 weeks old and weigh at least 4 pounds to use imidacloprid/permethrin/pyriproxyfen topical products. Permethrin is toxic to cats, so these products should never be used on cats.

Imidacloprid/permethrin/pyriproxyfen topical products are very well tolerated in dogs when used as directed on the label. There is minimal risk for overdose, severe side effects, or drug interactions in dogs. It will start to repel and kill adult fleas in 12 hours. It will start killing attached ticks in 24 hours. 

Imidacloprid/permethrin/pyriproxyfen topical products are available without a prescription from your veterinarian, from a veterinary pharmacy, and in pet stores.

Imidacloprid/permethrin/pyriproxyfen products are topical liquids placed in two to four places from the neck (between the shoulder blades) along the spine to the tail. Imidacloprid/permethrin/pyriproxyfen topical products are for treatment of fleas, ticks, mosquitoes, biting flies, and chewing lice in dogs and puppies. Dogs and puppies need to be at least 7 weeks old and weigh at least 4 pounds to use these products. 

All animals in the household should be treated with appropriate products at the same time to lessen the chances of the fleas returning. Do not use imidacloprid/permethrin/pyriproxyfen products on cats since permethrin is toxic to cats. If using imidacloprid/permethrin/pyriproxyfen products in a household with a cat, separate the cat from the treated dog for 24 hours so that the cat cannot ingest any of the medicine.

Imidacloprid/permethrin/pyriproxyfen topical products should be applied every 30 days. If the flea infestation is severe, imidacloprid/permethrin/pyriproxyfen topical products can be applied once every seven days for up to four weeks and then every 30 days. Do not apply to irritated skin. Imidacloprid/permethrin/pyriproxyfen topical products are waterproof after 24 hours. 

Avoid direct contact with eyes, skin, or clothing.

Always follow your veterinarian’s directions for giving medicines to animals. Remember to tell your veterinarian about any medicines, vitamins, supplements, or herbal therapies that you are giving your pet. Talk to your veterinarian before stopping any pet medicines. 

You and your veterinarian should monitor your pet for improvement of their condition as well as for side effects of the medicine. You should monitor for signs of improvement such as fewer live adult fleas and ticks, less itching, and less scratching. 

Do not use imidacloprid/permethrin/pyriproxyfen products in animals that are allergic to any of their ingredients. Do not use imidacloprid/permethrin/pyriproxyfen topical products in dogs that are less than 7 weeks old or weigh less than 4 pounds. Use with caution in animals that are in poor body condition (underweight), old, or frail. Use with caution in breeding, pregnant, or nursing pets.

Do not use imidacloprid/permethrin/pyriproxyfen products in cats since permethrin is toxic to them.

Imidacloprid/permethrin/pyriproxyfen topical products are usually well-tolerated in dogs when used as labeled. Side effects in dogs may include:

  • Scratching, redness, and discomfort at the application site
  • Slight hair loss
  • Excessive drooling if there is contact with the mouth

Serious side effects may include excessive drooling, vomiting, or diarrhea. 

If you suspect that your pet is having a serious side effect or may have been overdosed, call your veterinary clinic immediately. If it is outside of regular office hours, you may contact a local emergency veterinary hospital or an animal poison control center. 

You can reach the ASPCA Animal Poison Control Center at 888-426-4435 or the Pet Poison Helpline at 855-764-7661.

Using multiple medicines can sometimes change how your pet’s medicines work or increase your pet’s risk for serious side effects. Always tell your veterinarian about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements that your pet is using.

There is a low risk of imidacloprid/permethrin/pyriproxyfen topical products interacting with other medicines in dogs.

Do not use imidacloprid/permethrin/pyriproxyfen products if your dog is taking another flea and tick prevention medicine.

  • Keep imidacloprid/permethrin/pyriproxyfen topical products and the product packaging out of the reach of children.
  • Wash your hands after giving imidacloprid/permethrin/pyriproxyfen topical products to your dog.
  • Do not handle imidacloprid/permethrin/pyriproxyfen topical products if you are allergic to any of their ingredients.
  • Avoid contact of imidacloprid/permethrin/pyriproxyfen topical products with eyes, skin, and clothing.

Imidacloprid/permethrin/pyriproxyfen topical products are very well tolerated by dogs and the risk of an overdose is low. If you are concerned your dog is having an adverse reaction or if you suspect your pet has ingested the medicine, call your veterinarian or veterinary emergency clinic immediately.

If your pet misses a dose, give the dose when you remember and then restart the dosing interval from that date. Do not double the dose of the medicine. It is best to have your pet on year-round flea and tick prevention medication.

Store imidacloprid/permethrin/pyriproxyfen topical products in their original container at room temperature and protected from light until ready to use.