The Best Flea Treatment for Dogs

Strong enough to wipe out an infestation, safe enough to use on your pet
The 30-Second Review

The best flea treatment for dogs should be effective, convenient, and safe enough to use around kids and other pets. To find our top picks, we consulted three vets and an entomologist, researched active ingredients, then examined the top spot-on and oral meds ourselves. In the end, the right choice for you is a matter of your dog's needs and personal convenience.

Best Monthly Flea and Tick Treatment

Frontline Plus is a spot-on medicine. Its insecticide kills fleas, ticks, and lice while its insect growth regulator prevents new flea larvae from developing for up to a month. And its snap-off applicator was hands down the easiest to use.

PetArmor Plus and Sentry Fiproguard Plus use the same active ingredients for a few dollars less per treatment. The downside: the applicator is harder to open — and the medication is easier to spill.

Fast-Acting Flea Relief

Bayer Advantus Soft Chews kills 96% fleas within an hour and comes in a flavored chew that looks like a dog treat. Use once per day until your home is flea-free.

PetArmor FastCaps, Sentry Capguard and Capstar Flea Treatment Tablets all work the same way but come in a small pill. In our research, Sentry tends to be the cheapest.

The Best Flea Treatment for Dogs

To kill and prevent both fleas and ticks for up to a month, you’ll want to use a spot-on medicine. Frontline Plus uses fipronil to kill fleas, ticks, and lice, plus (s)-methoprene to keep fleas from growing and reproducing. Like all spot-on treatments, the medicine is applied to a small area on the back of your dog’s neck, so they can’t lick it off. Since it’s easy to accidentally come into contact with the medication, it’s best to monitor your pet and limit their contact with people and other animals for 24 hours.

PetArmor Plus and Sentry Fiproguard Plus use the same active ingredients to kill all stages of fleas and ticks but costs about half as much. However, their applicators aren’t as well-designed as Frontline Plus. When we opened the applicator, some of the medication leaked out — not ideal when handling insecticides. Frontline’s snap-off applicator kept more of the product intact until we were ready to apply.

If you just need to treat your dog fast, consider an oral medication. We liked Bayer Advantus Soft Chews, a chewable treatment that looks and smells like a dog treat. It starts killing fleas in under an hour, and you don’t have to worry about contact with other pets or children after application. The downside is that it only kills adult fleas — it won’t prevent against future generations, so you’ll need use it daily until your home is flea-free or switch to a spot-on after the first day.

Sentry Capguard, PetArmor FastCaps, and Capstar Tablets work just as quickly, but come in a pea-sized tablet you mix into your dog’s food. They all look identical, but Sentry Capguard tends to be the cheapest.

Our Picks for the Best Flea Treatment for Dogs

Best Monthly Flea and Tick Treatment

Frontline Plus Flea & Tick Treatment This popular medication lives up to the hype — one monthly treatment combats the entire flea lifecycle, plus ticks and lice. It also comes in an easy-to-squeeze applicator.

Frontline Plus, PetArmor Plus, and Sentry Fiproguard Plus were equally matched spot-on flea and tick medications.

All three use the same active ingredients: fipronil to kill bugs and (s)-methoprene to interrupt their growth cycle. One monthly application kills all stages of fleas, including eggs, larvae, pupae, and adults. They also combat multiple types of ticks and chewing lice.

You can even use these spot-on treatments on puppies as young as 8 weeks, or on breeding, pregnant, or lactating dogs. These dogs are just as susceptible to fleas and ticks – but puppies can’t always handle the insecticides used in other topical medications. Just make sure you’re using the right product for your pet’s size. Each spot-on manufactures different-sized doses for small (under 22 lbs.), medium (23–44 lbs.), and large (48–88 lbs.) dogs.

According to the label, Frontline starts killing fleas within four hours after application and kills 100% of fleas within 12 hours. PetArmor and Sentry claim to take 12 hours to begin killing fleas. They use the same active ingredients, so we’re not sure why they make different claims about how quickly the product will work. Regardless, studies have shown that a combination of fipronil and (s)-methoprene can kill 100 percent of fleas within seven days. While it’s not as fast-acting as the oral medicine we found, the insect growth regulator will eliminate a flea infestation much faster and much easier than a chew or tablet.

These products kill fleas the same way, but we uncovered a few noticeable differences during our hands-on testing. Specifically, we found that Frontline Plus uses a superior applicator. To open, you peel off the protective seal then snap off the long, narrow tip. That might sound like a minor detail, but compare that to PetArmor and Sentry’s applicators. We had to cut them open, and the medicine leaked out onto our scissors each time. You’ll have to take extra caution to make sure it doesn’t leave a chemical residue on you or anything you touch.

To apply Frontline, (left) you remove the applicator from the foil package, snap off the end of one of the applicators, and apply it on the back of your dog’s neck. Many spot-on treatments, like PetArmor Plus (center) and Sentry Fiproguard Plus (right), use similar application techniques.

We noticed a range of scents as well. Most spot-ons (Frontline Plus included) have a distinct chemical scent. That’s to be expected – these are chemicals after all – but Sentry and PetArmor were slightly more mild, even faintly citrus. But really, the difference is tiny, and the scent from any medicine will likely fade after a day or so.

Price-wise, Frontline Plus is on the higher side of average at around $10 per monthly treatment for the smallest-sized dose. PetArmor Plus is less than half that at $3 per treatment. Sentry Fiprogruard Plus sits in the middle at about $5 per treatment.

Fast-Acting Flea Relief

To give your dog relief from fleas as quickly as possible, use an oral medication. These medications work through your dog’s bloodstream to start killing fleas in under an hour, but they won’t protect against a future infestation or any other type of pest. You’ll give your dog a dose up to once per day until the infestation is under control, but if you have a persistent flea problem at home, or your dog is regularly exposed to ticks, follow up with a spot-on treatment after a few days. Never combine flea medicines at the same time without talking to your vet first.

Bayer Advantus Oral Flea Treatment Soft Chews for Dogs These flavored chews start working in under an hour, but won't protect against a future infestation.

Our favorite oral treatment is Bayer. Unlike most flea medications, your dog might actually want to eat it. These flavored chews look and smell like a regular dog treat, but contain imidacloprid — an insecticide acts through the dog’s bloodstream. When a flea bites the dog, it’s exposed to the insecticide and dies.

According to the label, Bayer kills 96 percent of fleas within an hour. Note that there are two different versions of the product – one for dogs under 25 pounds and one for dogs over 25 pounds.

PetArmor FastCaps, Sentry CapGuard, and Capstar Tablets work the same way, but come in a tablet instead of a chew. They all look identical — a small, white tablet no bigger than a pea, but you’ll probably still need to hide it in your dog’s food.

They each use nitenpyram, an insecticide that starts to kill fleas even faster – just 30 minutes. Your dog can take up to one pill per day, though one study found that the effects can last up to 48 hours. They’re are safe for cats and kittens too — just make sure you’re using the right dose for your pets’ weight.

The only difference between these three tablets is price. For dogs under 25 pounds, Sentry ($13) is the cheapest, but PetArmor ($14) is just a dollar more. Capstar ($22) is the most expensive.

PetArmor Fastcaps, Sentry Capguard, and Capstar tablets are all identical. Bayer Advantus Soft Chews resemble an everyday dog treat.

Did You Know?

There are lots of ingredients, but they all do one of three things.

IngredientsWhat They DoFound In
Cyphenothrin, fipronil, imidacloprid, nitenpyram, spinosadKill fleas by targeting their nervous systemFrontline, PetArmor, Sentry, Parastar, Flea5X, Certifect, PetAction, PetLock
(S)-methoprene, pyriproxyfenMimics flea hormones to prevent fleas from laying eggs and to keep eggs, larvae, and pupae from developing into adult fleasAdams, Bio Spot, Bayer, Frontline, PetArmor, Sentry, Flea5X, Certifect, PetAction, PetLock, Zodiac, Advecta, PetArmor, Vectra, K9 Advantix
N-octyl bicycloheptene dicarboximide (MGK 264)Speeds up the work of insecticidesSentry, Bayer, Bio Spot, Adams, Espree, Bio-Derm, Perfect Coat, PetLock

Southern states have the highest risk of flea infestation.

According to the Banfield Pet Hospital State of Pet Health 2016 Report, Louisiana, Alabama, and Florida were among the top five states with the greatest prevalence of fleas in cats and dogs. This is because fleas do best in warm, wet, and humid climates.

Fleas live in areas frequented by animals and humans and seek out dark, warm, humid places — usually carpets, bedding, under furniture, or in garden debris. Basic yard maintenance and vacuuming are the easiest ways to prevent an infestation.

We recommend talking to your vet.

We only looked at over-the-counter flea medicine, but there are more options available with a prescription. Dr. Ari Zabell at Banfield Pet Hospital, explained “Some of the current OTC medications are simply medications that were previously available only by prescription, but have since proven safe enough to be available over the counter.” Manufacturers make their products prescription-only to ensure that you talk to your vet beforehand. But that doesn’t mean prescription medicine isn’t safe. When your vet recommends a flea medication, they can account for your dog’s medical history and lifestyle.

The Best Flea Treatment for Dogs: Summed Up

Flea Treatment for Dogs
The Best
Frontline Plus Flea & Tick Treatment
Monthly Flea and Tick Treatment
PetArmor Plus Flea Medicine
Monthly Flea and Tick Treatment Runner-up
Bayer Advantus Oral Flea Treatment Soft Chews for Dogs
Fast-acting Flea Treatment
Sentry Capguard Flea Tablets
Fast-acting Flea Treatment Runner-up