With so many brands and choices of topical flea and tick medicines on the market, just what is the best spot-on flea treatment for dogs? To stop this article rivaling War and Peace for word-count, we are going to narrow this review to Frontline, Advantage and Advantix as they are quite simply the three most popular and best flea and tick medicines for dogs on the market today.
In this article we will start off with a simple overview for people that just want to get a treatment and are not too worried about the details. Even if this is you, please make sure that you read the pros and cons, especially if you have other pets besides dogs as some of these treatments can have very dire consequences on their health.
After that we will go into a more detailed comparison, covering how each works and the active ingredients, what parasites they are effective against, how to use each product and any safety concerns and side effects.
We will then finish off with our overall recommendations based on your individual circumstances.
Which Is The Best Flea Treatment For Dogs?
Deciding on the best flea treatment for your dog is no easy task and it really depends on your circumstances as much as the product. Before we go any further we need to address the effectiveness arguments of the various brands.
There are many posts out there saying that one brand is far more effective than another, however the simple fact is that Merial and Bayer have massive R&D budgets and Advantix, Advantage and Frontline Plus are the results of this research and all of them are very effective.
The bad news is that anyone who has ever studied even basic biology will know that all animals adapt to survive and this will include fleas who will become resistant to these treatments. The good news is I have yet to see any real evidence, either personally or in research, of fleas developing resistance to any of these products as yet.
So we have three high quality products But that still leaves us having to decide between Frontline vs Advantage vs Advantix, so which of these three are most suited to and best for you and your dog's needs?
Bayer K9
Advantix
Kills Fleas
Kills Flea Eggs
Kills Flea Larvae
Repels Fleas
Kills Ticks
Repels Ticks
Kills Lice
Kills Mosquitoes
Kills Biting Flies
Waterproof
Effective After 12 Hours
Lasts For 30 Days
Merial
Frontline Plus
Kills Fleas
Kills Flea Eggs
Kills Flea Larvae
Repels Fleas
Kills Ticks
Repels Ticks
Kills Lice
Kills Mosquitoes
Kills Biting Flies
Waterproof
Effective After 12 Hours
Lasts For 30 Days

Bayer
Advantage II
Kills Fleas
Kills Flea Eggs
Kills Flea Larvae
Repels Fleas
Kills Ticks
Repels Ticks
Kills Lice
Kills Mosquitoes
Kills Biting Flies
Waterproof
Effective After 4 Hours
Lasts For 30 Days

Bayer K9 Advantix II for Dogs Review
Bayer's K9 Advantix II is a once-a-month topical application for dogs and puppies that kills ticks, fleas, and mosquitoes. However the real strength of Advantix is that it not only kills but also repels the parasites that can potentially transmit disease-causing organisms, thus reducing the risk massively over treatments that only kill them.
However there are a few drawbacks to it, especially if you have cats as one of Advantix's active ingredients is toxic to cats. You can find out what Advantix does to cats here if you would like to jump ahead but first we will cover the good points.
Why Did K9 Advantix Win This Review?
Firstly, Advantix kills the most pests and parasites, which immediately puts it in pole position. This is only half the battle though as conventional parasiticides only kill fleas and ticks after they get to the dog's skin. This means there has to be physical contact and likely biting before the medicine works, increasing the risk of your dog catching something nasty.
However Advantix repels many types of flea, ticks, sand flies, stable flies and mosquitoes before they have the chance to bite. This means there is less chance that your dog will get any of these unpleasant passengers. If there are fewer pests on them the chance of your dog picking up things like Lyme's disease or heartworm will naturally be reduced.
It should be noted that none of these actually treats heart-worm, Lyme's disease etc., it's just if mosquitoes and ticks are repelled, there is less chance of contracting it.
Now for the bad news; Advantix is toxic to cats!
What Does Advantix Contain That Harms Cats?
Advantix has 3 active ingredients - Pyriproxyfen, Imidacloprid and Permethrin. The first two are shared with Advantage (another Bayer product) which are safe for cats, however cats have trouble breaking Permethrin down, so it stays active in their system longer than it does in humans or dogs. Since Permethrin is designed to affect the nervous system, causing muscle spasms, paralysis and death this is not something you want to stay active in your pet.
For this reason we would advice that you keep your dogs and cats apart for about 24 hours after you apply Advantix to minimise the risk of your cats getting any on them from close contact with your dogs.
Please don't be alarmed though, there are currently more than 1400 registered products containing permethrin. Everything from scabies and head lice treatments for people to cattle ear tags, flea collars, and of course spot-on treatments for dogs, and they are all regulated by the U.S. Food and Drug Administration (FDA). Advantix has been used by thousands of dog owners and have been found to be extremely safe.
How Long Does Advantix Take To Work?
Bayer's K9 Advantix is fast acting, it kills fleas within 12 hours of initial application and becomes fully effective against all pests within 48 hours. It will kill reinfesting parasites within 2 hours.
Where To Buy Bayer Advantix
Bayer Advantix is only available with a prescription, which you can get form your vet buy you can also get via online chemists Chemist Direct which is usually quite a bit cheaper than the vet - a good thing as Advantix is the most expensive of the spot-on treatments here.
Advantix comes in different dosages depending on the size of your dog, so make sure you get the right one.
Of course if you have cats you may want to look at other solutions, including our runner-up in this test, Frontline Plus.
Merial Frontline Plus Review
As a flea killer, Frontline Plus is very effective, certainly on par with any other treatment. It also kills and repels mosquitoes, kills ticks and can also control lice plus is also reported to help with mange. However it does not work on as many critters as Advantix and also does not work to repel as many either, leaving your pet at a higher risk of catching something nasty from their bites as even the very best treatments do not kill the parasites immediately.
Frontline Plus vs Advantix - When Would You Recommend Frontline Plus over Advantix?
Unlike Advantix and Advantage, Frontline Plus uses Methoprene and Fipronil as the active ingredients, which are entirely safe for cats. While Advantage is also safe for cats even though it uses some of the same ingredients as Advantix (Pyriproxyfen and Imidacloprid - it lacks Permethrin), it is simply not as effective at protecting your dog as it does not kill ticks or mosquitoes, giving Frontline the nod for cat owners.
How Long Does Frontline Take To Work?
Merial's Frontline Plus is the fastest acting of these three, it kills fleas within 12 hours of initial application and one study showed it can be as little as 4 hours. It kills ticks and lice within 48 hours. It will kill reinfesting fleas within 2 hours.
After application your dog should be kept dry for 48 hours (or 24 at a minimum) and after that time it will be waterproof, but Merial advise using a detergent free shampoo.
Frontline Plus vs Advantage
These two products use very different active ingredients. Frontline Plus is comfortably the better performer in both the range of creatures it kills, but also the efficacy on really heavy infestations, so we would typically recommend Frontline for homes that have both cats and dogs.
Where to Buy Frontline Plus
Meril Frontline Plus is available without a prescription, which means you can easily get it online which is usually quite a bit cheaper than the vet.
Frontline comes in different dosages depending on the size of your dog, so make sure you get the right one.
We have linked here to Amazon so you can see the best current prices available there if you hover over the picture of version you are interested in. If the price does not load up immediately, move your mouse off of the picture, then back over it and it should pop up.
Frontline For Small Dogs
For Dogs Weighing 2-10kg
Frontline For Medium Dogs
For dogs weighing 10-20kg
Frontline For Large Dogs
For dogs weighing 20-40kg
Frontline For Very Large Dogs
For dogs weighing over 40kg
Bayer Advantage II Review
Bayer Advantage II is a monthly topical application that is designed for use on dogs and puppies 7 weeks of age and older, weighing 3 lbs or more. It controls against all flea life stages and kills through contact, although the fleas do not have to bite your dog before it takes effect.
Both Advantage and Advantix are made by Bayer and both have Pyriproxyfen and Imidacloprid as active ingredients, but there is one big difference - Advantage lacks Permethrin. This makes it a far less versatile treatment as it does not kill many of the other pests that you would want to protect your dog from, such as fleas and mosquitoes and actually makes it less effective than Frontline Plus as an overall treatment.
How Long Does Advantage II Take To Work?
Bayer's Advantage II kills fleas within 12 hours of initial application and lice within 48 hours. It will kill reinfesting fleas within 2 hours.
When Would You Recommend Advantage over Frontline Plus?
Where Advantage picks up points is that it is not as harsh as Frontline, so it can be a good treatment for dogs that react badly to Frontline or Advantix.
The second point that it picks up is the cost - Advantage is considerably cheaper than both Frontline and Advantix. If you have several dogs, the costs can soon mount up.
Where To Buy Advantage II Online
Bayer Advantage is available without a prescription, which means you can easily get it online which is usually quite a bit cheaper than the vet.
Advantage comes in different dosages depending on the size of your dog, so make sure you get the right one.
We have linked here to Amazon so you can see the best current prices available there if you hover over the picture of version you are interested in. If the price does not load up immediately, move your mouse off of the picture, then back over it and it should pop up.
Advantage 40
For Dogs Weighing Up To 4kg
Advantage 100
For Dogs Weighing Between 4-10Kg
Advantage 250
For Dogs Weighing Between 10-25 KG
Advantage 400
For Dogs Weighing Over 25 KG
Each comes with 4 pipettes, which you should apply monthly if you have problems with fleas or 6-8 weeks during the summer months to prevent an outbreak.
Safety First - Potential Risks, Adverse Reactions and Side Effects
All three products have been extensively tested, and have been found to be extremely safe for use with dogs.
Just as with humans, some dogs can have an allergy or sensitivity to the oils used to hold the active ingredients in these products, but this will usually go after a day or two of applying the treatment. However some dogs have a worse reaction, so if it is not getting better after a few days, a visit to your vet may be in order.
However the biggest problems are with incorrect dosages or incorrect application.
Many people do not apply the right amount as all of these products come in different sizes, designed to work with different sized dogs. So if you have a Chihuahua and apply a large dog sized dose, you are far more likely to get an adverse reaction.
These treatments are all designed to be applied monthly, but some people, still seeing fleas, apply treatments more often. This will not actually make these treatments any more effective and simply run the risk of making your family pet ill.
So Why Didn't These Treatments Work For My Dog?
Many people apply the products incorrectly as these treatments need to be applied to the dog's skin. It is very easy to get this caught up in your pet's fur or do not ensure their dog does not lick it off, either of which will render it useless.
The application process is not too arduous (although for more excitable dogs a second pair of hands to hold them so they do not squirm around too much is a distinct advantage!) make sure you read the instructions thoroughly, especially for larger dogs as the doses may need to be applied to multiple spots on the dog for the treatment to be effective.
One of the most common reasons for these treatments being ineffective is down to the fake market. The reality is that flea treatments are big business and this will always draw the less honest into the market as creating some fake spot-on treatments is not difficult to do. So many of these reports of these spot-on treatments failing to do their job will be people who have unknowingly bought fake product.
The final reason is that the treatments are being effective, but you are not controlling the flea population elsewhere. Only about 5% of the fleas will be an adult, the rest will be eggs, larvae or in a cocoon. The treatments will kill the eggs, larvae and adults, but not a lot gets through a flea's cocoon.
They can remain in this state for quite a while, and once they emerge as adults, they will be back to biting and making more fleas. This is why it is imperative that you keep up a treatment regime for at least 6 months and also treat the rest of the house and yard to break this cycle. If you fail to do this you will never be able to kill the fleas as fast as they can reproduce.
So Which of These Spot-On Treatments Should I chose?
As shown in the comparison table at the top we highlighted Advantix as comfortably the most widely effective, even stopping parasites before they reach your pooch, which should make it an easy winner for most people.
However, you should not go out and buy Advantix until you have considered your dog, your other pets and your particular individual situation.
The aim of this article is to clear up the sometimes baffling scientific stuff that goes along with this type of product and make the decision process easier. With this in mind, we suggest that you go for Advantix unless you have a good reason not too.
For example if you have a cat and yours in an indoor or city dog you may find Frontline Plus the better choice as the advantages of Advantix are simply not needed and not having it in the house is safer for your cat.
If you have both cats and dogs that spend lots of time outdoors then I would still recommend Advantix, but make sure to keep your dogs well away from your cats for at least 24 hours after treatment and make sure they never get near the pipette!
So where does this leave Bayer's other product, Advantage II? To be honest, while it is very effective at killing fleas and lice we would only recommend it if mosquitoes and other parasites are not prevalent in your area and price is an issue or if your pet reacts badly to the other treatments here.
Finally remember that while treating your dogs is imperative to stop flea infestations, do not forget your home too as this is where the eggs will be hatching. So ensure that your home is kept clean and you use a good quality spray such as Indorex if you find any evidence of fleas on your pet.