Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Advantage II vs. Advantix II: We Asked a Vet (2024 Update)

Dr. Marti Dudley

By Dr. Marti Dudley

Advantage II vs Advantix II

Vet approved

Dr. Marti Dudley Photo

Written by

Dr. Marti Dudley

Veterinarian, DVM

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

Preventative care is at the forefront of appropriate animal stewardship. With all the products available on the market today, it can be difficult to know what prevention is best for your pet. Preventatives are available to help offer protection from parasites like fleas, ticks, and many others. Below is an outline of two very similar-sounding products—Advantage II and Advantix II— that both offer exceptional protection from all life stages of fleas.


At a Glance

Feature Advantage II Advantix II
Made by Elanco ✔️ ✔️
Kills all life stages of fleas ✔️ ✔️
Waterproof 24 hours after application ✔️ ✔️
Topical formulation ✔️ ✔️
No prescription needed ✔️ ✔️
Provides month-long protection ✔️ ✔️

hepper-dog-paw-divider 4

Advantage II

Advantage II Flea Spot Treatment

Advantage II is a topical preventative that offers protection against fleas and lice for dogs. Advantage II is effective against all stages of the flea life cycle and starts killing adult fleas within 12 hours of application. Killing fleas helps to prevent the spread of possible tapeworm infections. There is a cat formulation available as well. A dog formulation should never be used on a cat, although the active ingredients are the same.

Advantage II contains imidacloprid and pyriproxyfen. This product has been approved for use in puppies 7 weeks and older and weighing at least 3 pounds.


Prior to application, it is critical to note that the dog should be dry and remain dry for 24 hours after application. After 24 hours, this product will not lose effectiveness if exposed to water. Advantage II is easily applied by separating the fur along the back and applying the product directly to exposed skin. Large dogs will need to have the contents of one dose administered in several spots along their backs, whereas small dogs can have the entire contents applied in one location.

Possible Side Effects

As with any topical product, the skin should be monitored for signs of irritation where the medication was applied. Some dogs experienced gastrointestinal signs after application, including vomiting and diarrhea. If you are concerned your pet may be experiencing a reaction, please contact your veterinarian.

Special Product Considerations

In cases of severe flea infestations, the product can be applied more frequently than once a month. The drug insert suggests not using this product more frequently than once every 7 days and to not use weekly administration for more than four doses. Ensure that the product is not consumed and doesn’t come in contact with the patient’s eyes.

  • Cat and dog formulations available
  • Kills by contact, doesn’t require a bite
  • Available in four different sizes for dogs
  • Kills adult fleas within 12 hours
  • Available as pack of four or six
  • Doesn’t offer broad protection against different parasites, including ticks, mosquitos, intestinal parasites, or heartworms
  • People should avoid contact with pet until product has dried completely
  • Cats should be separated from dogs for 24 hours after application

hepper-dog-paw-divider 4

Advantix II

K9 Advantix II

Advantix II is a topical preventative that repels and kills fleas, ticks, mosquitos, biting flies, and lice. Having protection against fleas helps to prevent the risk of tapeworm development, which is associated with fleas. Additionally, ticks that may carry tick-borne illnesses like Lyme disease and ehrlichiosis are repelled and killed by this product.

Although Advantix II doesn’t prevent heartworm disease from occurring, it does repel and kill mosquitos that harbor the infectious stage of heartworm disease, offering another line of defense.

Advantix is not available for cats. This product has been approved for puppies as young as 7 weeks of age and weighing a minimum of 4 pounds. Active ingredients include imidacloprid, permethrin, and pyriproxyfen.


Advantix II is a topical product that is to be applied directly to the skin in several locations on the back between the shoulder blades and tail base. Prior to application, ensure that the patient is dry and remains dry for 24 hours following application.

Possible Side Effects

The skin to which the product is applied should be observed for signs of irritation. Gastrointestinal signs may be noted in some patients. If side effects occur, your veterinarian should be contacted.

Special Product Considerations

This product contains pyrethrins, which cats are very sensitive to, and exposure to a cat can result in death. If applied to or if ingested by a cat, your veterinarian needs to be quickly contacted. It is recommended that cats stay away from dogs with a recent application of Advantix II for 24–48 hours. Care should be taken to ensure the product is not consumed and does not contact the patient’s eyes.

If severe flea infestation is present, this product can be applied once every 7 days, but for no longer than four weekly treatments. After infestation has improved, the typical normal monthly treatment should be resumed.

  • Kills by contact, doesn’t require a bite
  • Kills adult fleas within 12 hours
  • Kills and repels ticks that can carry harmful bacteria that cause illness
  • Offers protection against mosquitos that can carry heartworm disease
  • Offers protection against biting flies and lice
  • Available as a single dose or pack of two, four, or six
  • Four dose sizes available
  • Can be fatal to cats
  • Cats should be separated from dogs for 24–48 hours after application
  • Dogs require another product to offer heartworm and gastrointestinal parasite coverage
  • People should avoid contact with pet until product is completely dry
  • Can be harmful to the environment


What Are The Differences Between Products?

Feature Advantage II Advantix II
Dog and cat formulations available ✔️ ✔️
Protection against ticks ✔️ ✔️
Repels and kills mosquitoes ✔️ ✔️
Potentially harmful to cats ✔️ ✔️
Protects against lice and biting flies Lice only ✔️

What the Users Say

Reviews from popular consumer websites show overall support for both products. As with any reviews, there are some high ratings and low ratings sprinkled in.

Advantage II received a majority of 5-star reviews from common pet consumer websites, with consumers stating that this product had successfully prevented flea problems in their pets for years. A few reviews suggested that the product did not work well but referenced parasites not claimed to be managed by Advantage II.

Most reviews seemed to feel that Advantix II offered great protection against fleas, but there were some reviews that questioned the tick efficacy. Additionally, reviewers seemed pleased with the efficacy against biting flies. The large majority of online reviews from three major pet consumer websites gave Advantix II five out of five stars.

dog flea treatment
Image Credit: goodluz, Shutterstock

Which Product Is Best for My Dog?

The answer to that will be dependent on each patient and other personal factors. Advantix II offers a wider spectrum of prevention than Advantage II; however, if your home is shared with a cat, it may be advantageous to avoid Advantix II.

Depending on where you reside, ticks may pose a real threat, making Advantix II appealing due to the broad tick protection offered.

In general, Advantage II is slightly less expensive than Advantix II. Be sure to speak with your primary care veterinarian to discuss which products may be best for your companion.

hepper-dog-paw-divider 3

In Summary

Both Advantage II and Advantix II do not require a prescription from a veterinarian and both products offer great protection for your dog. It is important for the product to be used as it was intended to help ensure adequate protection against parasites.

Although both products are considered safe, an individual patient can experience drug sensitivities regardless of the product used. Prior to using a product, it is important to read the drug insert thoroughly. Your veterinarian will be a great source of information when deciding which product may be best suited for your companion.

Featured Image Credit:

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database