Advantage II for Cats gets consistently high ratings from both vets and cat owners. Though it doesn't work for every cat, it's more consistently effective than any other product. One monthly dose, applied to the back of the cat's neck, kills adult fleas as well as eggs and larvae. Most owners find it easy to apply, but some say it's a bit messy. Side effects are very rare but can be serious.
Beats the competition. Advantage II for cats contains two key ingredients: imidacloprid, which kills adult fleas, and pyriproxyfen, which stops the growth of flea eggs and larvae. Vets describe Advantage II for Cats as very effective, and most owners agree. Many reviews on pet-product websites specifically note that this product worked when its leading competitor, Est. $60 for a 6-month supply failed. However, some owners complain that Advantage II didn't work for their cats or that its effects wore off before the month was out. A few owners say that for them, the original version of Advantage (without pyriproxyfen) worked better.
Few problems, but some can be serious. Vets describe Advantage II for cats as a very safe product. Most reviews from cat owners say that this product worked without causing any side effects; a few even note that it was the only product their pets could tolerate without an adverse reaction. However, we did see a few reports at Amazon.com from owners whose cats suffered side effects -- some serious -- after use. While these problems appear to be extremely rare, it's probably wise to watch your cat closely after using Advantage II and be ready to call the vet if necessary.
No fuss, slight muss. Advantage II comes in single-dose tubes. To apply it, you part the fur at the back of the cat's neck and squeeze out the entire contents of the tube onto the skin. It needs to be applied in a spot the cat can't lick, as ingesting it can cause excessive drooling and hyperactivity. Most owners find Advantage II very easy to apply, although some cats may put up a struggle. The product may leave a greasy spot on the back of the neck; some owners say this dries quickly, while others say it stays wet for days and rubs off on the owner's hands. Most owners don't find the smell bothersome.
There are more than 2,600 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 and 4.6 stars for ease of use.
Review: Advantage II, Contributors to 1800PetMeds.com, As of December 2013
Advantage II for Cats receives more than 1,400 user reviews here, with additional reviews at Amazon.com spread across multiple pages. Most cat owners say they find this product effective, fast-working and easy to apply. However, some owners say it didn't work, and a few complain of dangerous side effects.
Review: Bayer Advantage II Flea Control for Cats, Contributors to Amazon.com, As of December 2013
We found about 600 reviews of Advantage II for Cats at Petco.com. Its overall rating is 4.6 stars out of 5, and 93 percent of users recommend it. Several users say this is the only flea product that has worked for them without causing harmful side effects.
Review: Advantage II Once-A-Month Cat & Kitten Topical Flea Treatment, Contributors to Petco.com, As of December 2013
4. All Feline Hospital
Vets at the All Feline Hospital in Lincoln, Neb., name Advantage II for Cats as one of the best flea treatments available without a prescription. They say the product is "very safe and effective," but they stress that rigorous vacuuming is also required to remove fleas from the home.
Review: Flea Eradication, Staff of All Feline Hospital, Not Dated
Advantage II for Cats has about 250 reviews at PetSmart.com, spread across multiple pages -- including about 140 here. Cat owners award it 4.4 stars out of 5 overall, saying it's effective, fast-working and a good value. Several reviews say that this product worked when Frontline Plus failed.
Review: Advantage II Cat 6-Pack, Contributors to PetSmart.com, As of December 2013
6. Mid Hudson Animal Hospital
Vets at Mid Hudson Animal Hospital in Hyde Park, N.Y., recommend the original Advantage as their top pick for flea control in cats, saying it appears to be more effective than Frontline. However, this article does not specifically discuss the current formulation, Advantage II for Cats.
Review: Recommendations for Flea Control, Staff of Mid Hudson Animal Hospital, Not Dated
Veterinarian Carol S. Foil says the original version of Advantage for Cats kills fleas fast and maintains "100% killing" for at least two weeks. She also says that Nylar, the ingredient added to Advantage II for Cats, is "extremely effective against flea eggs."
Review: Flea Control, Carol S. Foil, Not Dated
This directory from the Natural Resources Defense Council gives Advantage II for Cats a safety rating of two "paws" out of three, or medium risk. Editors note that its key ingredient, imidacloprid, shows signs of toxicity in rats but is generally classified as low risk for humans.
Review: GreenPaws Flea and Tick Products Directory, Editors of SimpleSteps.org, Not Dated