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Advantage II for Dogs Review

By: Carl Laron on May 12, 2017

Bottom Line

Advantage II for Dogs contains two ingredients, one that kills adult fleas and one that prevents immature fleas from developing. Dog owners find it more effective than other topical flea treatments, and they say side effects are rare. Its chief drawback is that it doesn't kill ticks.


  • Kills adult fleas, eggs and larvae
  • Highly effective
  • Side effects are rare
  • No prescription required


  • Leaves greasy residue
  • Doesn't kill ticks
Our Analysis
Read Amazon Reviews

Breaking it down


Not perfect, but better than most. . Most dog owners find Advantage II for Dogs very effective saying it works fast to wipe out fleas. Many say that this product worked when Frontline Plus for Dogs (Est. $35 and up for a three month supply) failed. However, some reviewers complain that this flea treatment was ineffective or stopped working before the month was up, requiring an extra dose. A few owners say Advantage II used to work for their dogs but no longer does. However, most veterinarians don't report similar results and veterinarian dermatologist Jon Plant says that "the Advantage line of products are generally very effective for flea control in most situations, when used as directed (monthly)."


Side effects are rare. We saw thousands of reviews for Advantage II from dog owners at various pet-product stores, and the vast majority of them say this product had no side effects. Only a handful of owners at Amazon.com say that their dogs had bad reactions to the drug, typically involving vomiting and diarrhea. It is important to keep the fluid out of the dog's eyes and mouth -- and out of your own as well. The product insert says to wash your hands thoroughly after applying and to call poison control if it's swallowed or gets in your eyes.

Ease of use

Leaves a greasy spot. Advantage II comes in a single-dose tube that you squeeze onto the dog's skin. Small dogs get the entire dose between the shoulder blades; on larger dogs, it's applied at three or four points along the back. In the reviews we consulted, owners don't describe any problems applying it to their dogs. However, a few complain that it leaves a persistent, greasy residue on the dog's fur.

Our Sources

Contributors to Amazon.com, As of May 2017

We found nearly 2,400 reviews for Advantage II for Dogs at Amazon.com. Most dog owners find it effective, with many saying it works where other products fail. However, some owners say it didn't help their dogs or stopped working before the month was up. It earns a 4.1-star rating.

Contributors to 1800PetMeds.com, As of May 2017

There are more than 2,860 user reviews of Advantage II at this online pet pharmacy, covering both the dog and cat versions of the product. Users give it 4.2 stars out of 5 overall, with 4.2 stars for effectiveness.

Contributors to Petco.com, As of May 2017

Advantage II for Dogs 11 to 20 pounds (medium dog) receives almost 280 reviews from dog owners at Petco.com. Its overall rating is 4.4 stars out of 5, with most owners granting it 5 stars. Owners largely find it effective, but some complain that it didn't work or lost its efficacy after about a week.

Jon Plant, DVM, DACVD, May 3, 2015

Veterinarian Jon Plant, a board-certified veterinarian dermatologist who runs the SkinVet clinic in Oregon, notes that Advantage II and other products in the line is "generally very effective," though he says that best results are achieved when the product is used monthly.

Editors of SimpleSteps.org, Not Dated

This directory from the Natural Resources Defense Council gives Advantage II a safety rating of two "paws" out of three, or medium risk. Editors note that its key ingredient, imidacloprid, is toxic to the nervous system, but that the way it works reduces its toxic effects in humans and is listed as a "least toxic" and "reduced-risk" pesticide by various authorities. The IGR, pyriproxyfen, "has very little toxic effect on humans".

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