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 with three vets and an entomologist, researched active ingredients, and examined the top spot-on and oral meds ourselves.

Best Monthly Flea and Tick Treatment

Frontline Plus uses an insecticide to kill fleas, ticks, and lice plus an insect growth regulator to prevent flea larvae from developing for up to a month.

PetArmor Plus uses the same active ingredients for a few dollars less per treatment.

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 Tablets all work the same way but come in a small pill.

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 accidently 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 uses the same active ingredients to kill all stages of fleas and ticks but costs $4 dollars less per treatment. We also liked that the medication is cherry-scented — much more pleasant that the nail polish remover-like scent of Frontline Plus. However, its applicator wasn’t as well-designed as Frontline’s. Some of the medication leaked onto our scissors when cutting it open. Frontline’s snap-off applicator kept more of the product intact until we were ready to apply.

If you only need to treat an existing flea problem, consider an oral medication. We liked Bayer Advantus Soft Chews, a chewable treatment that looks and tastes 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.

Sentry Capguard, PetArmor FastCaps, and Capstar Tablets work just as quickly, but come in a cheaper, pea-sized tablet you mix into your dog’s food.

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 and comes in an easy-to-squeeze applicator.

Frontline Plus and PetArmor Plus were equally matched spot-on flea and tick medications. Both use the same two 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, plus multiple types of ticks and chewing lice. Plus, you can use it on puppies as young as 8 weeks as long as they meet the 5-pound weight requirement, or on breeding, pregnant, or lactating dogs.

All spot-on applicators work similarly: cut open the applicator, place it between your dog’s shoulders, and squeeze a tablespoon-sized amount of liquid onto your dog’s skin. After applying the product, you’ll want to avoid petting the wet area around your dog’s neck for at least 24 hours. 

PetArmor Plus It uses the same active ingredients as Frontline Plus, for about $4 less per month.

According to the label, Frontline starts killing fleas within 4 hours after application and kills 100% of fleas within 12 hours. Pet Armor claims 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 the formulas are similar, Frontline’s transparent applicator was noticeably better — we could see the medication inside as we were cutting it open. When we opened the PetArmor applicators, some liquid leaked out onto our scissors each time. Both were easy to apply, but PetArmor had a surprisingly pleasant cherry scent, whereas Frontline’s spot-on only smelled like chemicals.

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.

Price-wise, Frontline Plus is on the higher side of average across all flea medications at $10 per treatment (for the smallest-sized dose). PetArmor Plus is less than half that at $3 per treatment. Sentry Fiprogruard Plus is a close runner-up. It uses the same active ingredients and applicator as PetArmor, but costs $2 more per treatment.

Fast-Acting Flea Treatment

To treat fleas quickly, without leaving a chemical residue on your pet, use an oral medication. These insecticides act through the dog’s bloodstream, so there’s no risk of exposure like there is with a spot-on treatment.

Take note: These medications are only intended to treat a flea infestation, up to once per day until the infestation is under control. If your home has a persistent flea problem, or your dog is regularly exposed to ticks, try a spot-on or talk to your vet about other oral medications.

Bayer Advantus Oral Flea Treatment Soft Chews for Dogs These flavored chews start working in under an hour, but only kill adult fleas.

Our favorite 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 that mimics nicotine and attacks the nervous system of fleas. According to the label, Bayer kills 96 percent of fleas within an hour — much faster than other spot-on medications that take at least four hours to begin killing fleas.

PetArmor FastCaps These tablets start killing fleas in as little as 30 minutes.

PetArmor FastCaps, Sentry CapGuard, and Capstar Tablets work the same way, but come in a tablet instead of a chew. It’s about the size of a pea, but you’ll probably still need to hide it in your dog’s food. Each tablet uses nitenpyram — an insecticide that starts to kill fleas in 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.

All three of these tablets are identical in look, smell, and packaging. The only difference between them is price. Sentry ($13) is the cheapest. But if you can’t find Sentry, PetArmor ($14) is just a dollar more. Capstar ($22) is the most expensive.

Our three picks for tablets are all very similar in size and appearance. Bayer Advantus Soft Chews, on the other hand, 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

Cats and dogs have the same kind of fleas.

There are two different types of fleas: the cat flea (Ctenocephalides felis) and the dog flea (Ctenocephalides canis). Despite their names, cat fleas are the most common fleas found on dogs (and cats!) in North America.

Still, it’s important to use medicine formulated specifically for your pet’s size and species. Many sprays, shampoos, and powders contain pyrethrins and pyrethroids — two ingredients that are toxic to cats and have been known to trigger seizures.

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.

Always talk to your vet before starting a new medication.

According to the American Veterinary Medical Association, there are many factors that can determine which type of medication to use, including age, breed, lifestyle, and size. Some breeds have sensitivities to certain ingredients, and because insecticides target fleas’ nervous systems, size is also a factor. A high dose on a small dog can affect the dog’s nervous system, and a low dose on a large dog might not do the trick.

If you have any questions or concerns, it is a good idea to talk to a vet first so that you can decide together the best medication for your dog.

The Best Flea Treatment for Dogs: Summed Up

Flea Treatment for Dogs
The Best For...
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