Frontline Vs Advantix: What Woof Is The Difference? (We Asked A Vet)
With the warmer weather, I’ve been treating more dogs for fleas and ticks. Unfortunately, as soon as we start to enjoy our sunny summer these pesky critters make their holiday home on our dogs.
Frustrating to eliminate, many owners and their dogs are driven to distraction. A quick look online reveals a plethora of products are available, but it’s so difficult to know what will work best for your pup and lifestyle. In this post, we’ll walk through two available products and find out who comes out on top in Frontline Plus vs Advantix for dogs.
- What do Frontline Plus and K9 Advantix II actually do?
- Frontline Plus Review
- K9 Advantix II Review
- Frontline Plus vs K9 Advantix II:key differences
- Frontline Plus vs K9 Advantix II: Effectiveness
- Who scores better on price?
- Does my dog really need flea and tick medications?
- Tick-borne diseases you should know about
- F.A.Qs

Both of these products are licensed for the treatment and prevention of ectoparasitic infestations. This means they kill and protect your pet against parasites that live in their fur and skin.
Application
Frontline Plus is a topical spot-on medication. It’s sold in pre-measured ampoules that you simply snap open, part the fur between your pup’s shoulder blades and squeeze the contents onto their skin.
What does Frontline Plus kill?
How does this product work?
The pre-measured liquid dose rapidly absorbs into the skin and is stored within the hair follicles where it is slowly released at a continuous rate over about 30 days.
How long does Frontline Plus protect dogs?
Frontline Plus works consistently for 30 days, protecting your dog from re-infestation.
Active ingredients
- Fipronil - Targets adult fleas and ticks disrupting their nervous systems
- (S)-methoprene - Targets flea eggs and larvae preventing them from developing.
How are the ingredients delivered?
A specific dose is applied to your dog’s skin and is quickly absorbed where it is stored in hair follicles and steadily released to protect your pet from flea and tick infestations.
How long does it take Frontline Plus to start working?
Risks or possible side effects
What We Like About Frontline Plus
- Can be used on puppies only 8 weeks old once they’re heavier than 4.4lbs
- Suitable to be used for pregnant and lactating bitches
- Starts to work in just 4 hours
What We Don't Like About Frontline
- Require’s a monthly application to maintain protection
- Potential resistance of fleas to fipronil developing (Maddison, Page & Church, 2008)
- If your dog ingests the product it can cause salivation, vomiting and diarrhea
Veterinary Opinion
Monthly application is pretty convenient and many practices allow you to set up automatic reminders so your dog never misses another dose.

Application
K9 Advantix II is packaged in single-dose pipettes to allow simple application to your pet’s skin. Simply, part the hair between your dog’s shoulder blades and squeeze all the contents onto their skin.
What does K9 Advantix II kill?
This product kills and repels not only fleas and ticks but also mosquitoes and biting flies. Great for those pups that enjoy mucky puddles and animal poop.
How does this product work?
How long does K9 Advantix II protect dogs?
Active ingredients
- Imidacloprid which targets adult and larval flea stages
- Permethrin is effective against ticks and mosquitoes and also repels them following administration
- Pyriproxyfen is present as an insect growth regulator which stops flea eggs and larvae from developing
How are the ingredients delivered?
Measured doses are applied in liquid form onto your pet’s skin where they are rapidly absorbed into their skin. The product is stored in the oils on a dog’s skin and persists for 4 weeks.
How long does it take K9 Advantix II to start working?
Risks or possible side effects
Do NOT administer to cats and keep your cat away from any recently treated dog to prevent them from licking or coming into contact with the product.
What We Like About K9 Advantix II
- Works against mosquitoes and biting flies as well as fleas and ticks
- Can be used on puppies as young as 8 weeks old
- Waterproof
What We Don't Like About Advantix
- Toxic to cats so you need to keep recently treated dogs away from any cats in the home (or avoid using if cats are in the home)
- Not fully effective if dogs are in heavily infested areas
- The company recommends only 1 bath for your pup per month
Veterinary Opinion

Both products reviewed in this post are effective against ticks and all life stages of fleas. There have been some anecdotal reports of flea resistance to fipronil (Maddison, Page & Church, 2018), the active ingredient in Frontline Plus, these are rare though and unlikely to affect most dogs.
A quick scan will show that per dose Frontline Plus works out easier on your pocket, however, K9 Advantix II does have the added protection against mosquitoes and biting flies which may be necessary for some dogs.

The short answer is yes! No matter where you are in the country (or the world) fleas and ticks will always be present. While both can be bothersome for our dogs and upsetting for us to watch, these bugs can also spread diseases. Many of these diseases are difficult to treat or not treatable at all which makes the need for these preventative medications even more important.
Ticks can spread many diseases, they do this by biting and feeding on your pet. The best-known disease spread by ticks is probably Lyme disease but there are others out there to be aware of and prepared.
- Lyme disease is caused by the bacterium Borrelia burgdorferi and is often spread by deer ticks (Ixodes scapularis). This is a nasty disease, causing lethargy, lameness and even kidney disease; this disease can also affect humans.
- Anaplasmosis, this is caused by a number of Anaplasma species of bacteria and can be spread by both deer and brown dog (Rhipicephalus sanguineus) ticks. The primary signs we tend to see in our pets are lethargy, high temperature, and blood tests will usually show abnormally low numbers of red blood cells.
- Erlichiosis is yet another bacterial disease and is caused by a few species of the bacterium Erlichia which leads to immune system and blood disorders. The main tick culprits for spreading this are the brown dog, lone star (Amblyomma americanum), and American dog (Dermacentor variabilis) ticks.
- Rocky Mountain Spotted Fever is caused by the bacterium, Rickettsia rickettsii and is spread by the American dog, Brown dog and Lone star ticks. The illness usually appears within a few weeks of a tick bite and can be fatal without treatment. The main signs are fevers, stiff joints, and swollen lymph nodes.
How old does my puppy need to be before using these products?
Both products can be administered to puppies once they are over 8 weeks of age and weigh more than 4.4lbs.
My dog is pregnant/nursing puppies but she has fleas, can I still use these?
Yes, both products are safe to use on pregnant and lactating bitches.
My dog is sick or has been diagnosed with a long term illness, can I use these medications?
Both of these products are safe, however, I would advise that you speak with your veterinarian who can best advise you about your pet’s particular illness before using any product.
Can I mix and match flea treatments?
No, mixing treatments increases the risk that your pet will have a negative reaction and may lead to toxic doses being administered. If you’re concerned that a product hasn’t worked how you hoped, speak with your veterinarian before using any other product as some products can take a few days to show results.
What’s the expiration for these products?
Frontline Plus has no expiration date, the company recommends that the pipettes are fine to use once they have been stored at room temperature. Similarly, K9 Advantix II does not expire and should be stored at room temperature.
Final thoughts

The battle of Frontline vs Advantix for dogs in this post is close, both are very good products and have similar durations of action.
Adverse reactions are possible with any product, but these are rare and tend to be mild if they do occur. However, you should always discuss treatment options with your veterinarian before the application of any product particularly if your pet has any medical illnesses or has sensitive skin. Your vet will always be able to provide you with the best advice for your dog’s unique needs.