Frontline Plus vs. K9 Advantix II: Which Is Better? Our Vet Answers
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Ticks, fleas, and other external parasites are more than just a nuisance to your dog. They carry and transmit life-threatening diseases, such as heartworms, Ehrlichiosis, and Babesiosis. They also cause allergies, itching, anemia, abscesses, and paralysis, so it’s critical to keep your pet parasite-free.
There is no shortage of external parasite treatments, so finding the best one for your beloved dog can feel overwhelming. To help you out, we’ll compare two popular products: Frontline Plus and K9 Advantix II.
Review Summary
There’s no clear winner here; Frontline Plus and K9 Advantix II are effective products. The product that’s right for your pup depends on your dog’s specific needs and the parasite populations in your geographic location.
K9 Advantix II has a broader spectrum of activity compared to Frontline Plus. In addition to killing and preventing ticks, fleas, and chewing lice, it also kills mosquitoes and biting flies. So, if you live in an area where mosquitoes or biting flies are an issue, K9 Advantix II is your best bet.
If you have cats, you may be better off choosing Frontline Plus. Permethrin, one of the active ingredients in K9 Advantix II, is toxic to cats. Treated dogs should be separated from cats for 24 hours after applying K9 Advantix II, so it’s probably easier and safer to use Frontline Plus.
Frontline Plus is also a better option for dogs that love to swim. Although both products are technically waterproof, if a dog is frequently exposed to water, K9 Advantix II may not work for the full 30 days.
At a Glance
- Active ingredients: Fipronil and (S)-methoprene
- Effective against adult fleas, flea eggs, flea larvae, adult ticks, and chewing lice on dogs
- Provides protection for 30 days
- Applied as a topical treatment to the skin between the dog’s shoulder blades
- Waterproof after 24 hours
- Approved for use on all dogs, including puppies as young as 8 weeks and weighing at least 5 pounds
- No prescription required
- Active Ingredients: Imidacloprid, permethrin, and pyriproxyfen
- Effective against ticks, fleas, flea eggs, flea larvae, mosquitoes, biting flies, and chewing lice on dogs
- Repels parasites
- Provides protection for 30 days
- Applied as a topical treatment to the skin along the top of the dog’s back
- Waterproof after 24 hours
- Approved for use on dogs, including puppies as young as 7 weeks and weighing at least 4 pounds
- No prescription required
Overview of Frontline Plus
Frontline Plus is a topical medication used to treat and prevent ticks, fleas, and chewing lice on dogs older than 8 weeks and weighing at least 5 pounds. It contains the active ingredients Fipronil and (S)-methoprene. Fipronil kills adult fleas, ticks, and chewing lice by affecting their nervous system, while (S)-methoprene prevents the development of flea eggs and larvae. Frontline Plus prevents flea reinfestation by interrupting the flea life cycle at multiple stages, which is a common problem.
Frontline Plus comes in five different pipette sizes, and each corresponds to a specific weight range. To use, snap the pipette open, part your dog’s hair, and apply the medicine directly to the skin between your dog’s shoulder blades. Once Frontline Plus is applied, it quickly covers the entire dog and collects in the sebaceous glands of the skin.
The medication is slowly released from these glands into the surrounding skin and hair follicles, where it protects against parasites for 30 days. Fleas and ticks are killed on contact and do not have to bite the dog in order to die.
- Provides protection for 30 days
- Waterproof after 24 hours
- Effective against the entire flea life cycle and prevents future flea infestations
- Approved for use in breeding, pregnant, and lactating dogs
- Some dogs experience temporary irritation, such as itching and redness at the site of application
- Does not repel all parasites
Overview of K9 Advantix II:
K9 Advantix® II is a topical medication that kills ticks, fleas, mosquitos, biting flies, and chewing lice on dogs and repels them. Parasites are killed through contact and do not need to bite the dog to die. One application of K9 Advantix® II provides protection for 30 days.
K9 Advantix® II contains the active ingredients imidacloprid, permethrin, and pyriproxyfen. Imidacloprid and permethrin disrupt the nervous system of parasites, causing paralysis and eventual death. At the same time, pyriproxyfen prevents flea eggs and larvae from maturing into adult fleas, effectively breaking the flea life cycle and preventing re-infestation.
K9 Advantix II comes in four different pipette sizes, each corresponding to a specific weight range. To use, apply the contents of the pipette to the skin along the top of your dog’s back, from the shoulders to the base of the tail, in four to six spots. The hair should be parted at each spot before the liquid is applied.
K9 Advantix® II may cause side effects, such as skin irritation (redness, scratching, or other signs of discomfort), or gastrointestinal signs, such as vomiting or diarrhea.
- Kills and repels parasites
- Fast-acting
- Broad spectrum of activity: kills ticks, fleas, mosquitos, biting flies, and chewing lice
- Toxic to cats due to its permethrin content
- Cats should be kept away from dogs treated with K9 Advantix® II for 24 hours following application
- In severe flea infestations, re-treatment may be necessary before the end of 30 days
- May cause skin irritation and GI upset
The Comparison
At first glance, Frontline Plus and K9 Advantix II are very similar. Both are topical, waterproof products that last 30 days. There are, however, some key differences between them. To help you decide which is best suited to your pup, we’ll compare the products and see how they stack up against each other.
Coverage
The critical difference between Frontline Plus and K9 Advantix II is their coverage. Both products kill ticks, fleas, and chewing lice; however, K9 Advantix II provides broader coverage, as it also kills mosquitoes and biting flies.
In some geographic locations, mosquitoes transmit diseases like heartworms to dogs. Although K9 Advantix II is not a heartworm preventive, it may reduce the risk of a dog contracting the disease by killing and repelling mosquitos. For optimal protection, K9 Advantix II should be paired with a monthly heartworm preventive.
If you live in an area with mosquitoes and biting flies, K9 Advantix II is a better option than Frontline Plus.
Ease of Application
Frontline Plus is applied to the skin between the dog’s shoulder blades in a single spot, whereas K9 Advantix II is applied evenly to four to six spots on the back from the shoulders to the base of the tail. Although both products are easy to apply, some owners find Frontline Plus a little easier, as it only requires application in a single spot.
Water Resistance
Frontline Plus and K9 Advantix II become water-resistant 24 hours after application; however, if a dog is frequently exposed to water, K9 Advantix II may not work for 30 days. If your dog often gets wet, Frontline Plus is a better option.
Price
K9 Advantix II is slightly more expensive than Frontline Plus. While this may be the case, the price difference is justified as it provides broader coverage.
Time to Take Effect
K9 Advantix II takes half the time of Frontline Plus to work. Frontline Plus® kills fleas within 24 hours of contact and ticks within 48 hours of contact, whereas K9 Advantix II starts to kill fleas, ticks, and mosquitoes in 12 hours.
What the Users Say
Given that Frontline Plus and K9 Advantix II are two of the most popular flea and tick medications on the market, there is no shortage of reviews.
Positive Feedback
Unsurprisingly, both products receive predominantly positive feedback from users. Frontline Plus users feel the product is highly effective at killing fleas and preventing re-infestation. They like that it is waterproof and continues to work even if their dog repeatedly gets wet.
K9 Advantix II users like its effectiveness and ease of use. They also like its broad spectrum of activity, which includes treating ticks and fleas, killing and repelling mosquitoes, and repelling biting flies.
Negative Feedback
While most of the feedback was positive, two issues accounted for most of the negative feedback for Frontline Plus and K9 Advantix II. Some users were dissatisfied with the products’ negative side effects, while others mentioned that Frontline Plus and K9 Advantix II didn’t seem to work.
A small number of Frontline Plus users reported that their dogs experienced side effects, such as redness and itching, at the application site, while other users reported that K9 Advantix II caused irritation, vomiting, and diarrhea.
While all medications have risks, Frontline Plus and K9 Advantix II rarely cause side effects. When side effects occur, they tend to be mild and resolve quickly. Unfortunately, it’s not possible to predict which dogs will experience adverse reactions; however, there are some things you can do to minimize potential reactions. Always read the product label before applying the product, and apply only the recommended dose based on your dog’s weight.
While it is not possible to say why Frontline Plus and K9 Advantix II did not work for some dogs, user error may play a role, and it’s possible that the treatments weren’t applied correctly.
Conclusion
There is no clear winner here. Frontline Plus and K9 Advantix II are effective products that have their place in the fight against external parasites. Ultimately, the product that is right for your pup depends on your dog’s needs and the parasite populations in your geographic location.
Frontline Plus is the best option if your dog frequently gets wet or if you have cats living in your home, whereas K9 Advantix II is the best option if your dog needs coverage against mosquitos or biting flies.
Your veterinarian is the best person to speak to for customized recommendations for your pet.
