The Best Flea Treatment for Dogs
Strong enough to wipe out an infestation, safe enough to use on your pet
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.
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.
How We Found the Best Flea Treatment for Dogs
We started with 68 medications — collars, chewables, shampoos, sprays, and spot-ons — to choose from. These were the most common over-the-counter flea treatments for dogs available online and in stores, including 1800PetMeds, Petco, Drs. Foster & Smith, and PetSmart.
From there, we talked to pet and insect experts and researched ingredients to find the medication that works the best and is safe enough to use in homes with kids and other pets.
We learned that some medications are more practical than others.
There are lots of types of medication, but they do the same thing: fatally attack fleas’ nervous systems. So, we wanted to find treatments that were easy to administer. We quickly realized spot-ons, oral tablets, and collars were going to be more convenient than shampoos and sprays.
- Spot-ons are a small, concentrated liquid applied to the back of a dog’s neck once a month. Within 24 hours, the medication dissipates into the natural oils on the dog’s skin, killing fleas and preventing new generations from developing for up to a month.
- Oral chews and tablets use insecticides that transfer to the dog’s bloodstream in under an hour. When a flea bites the dog, it’s exposed to the insecticide and dies. While chews and tablets work faster than any other product, they only last 24 hours — oral over-the-counter medication are only intended to treat an existing flea problem. They won’t protect your dog from a future infestation.
- Collars contain insecticides that either repel fleas or absorb into dogs’ fat layer to kill fleas. The collars we found last anywhere from six to twelve weeks.
- Shampoos kill adult fleas quickly, but typically only last 24 hours, like oral tablets and chews. The medication is potent and is usually only necessary for animals with a severe infestation.
- Sprays linger in the oils on a dog’s skin. They work similar to spot-ons but more diluted and require you to apply the medication all over your dog’s body as often as once a week.
While we found a handful of “natural” products that use essential oils like clove oil, cedarwood oil, and lemongrass oil, none of the vets we spoke to could verify that these products could kill fleas, so we didn’t include them in this review.
Adams Flea & Tick Cleansing Shampoo
Adams Flea & Tick Spray
Adams Plus Flea & Tick Spray for Cats and Dogs
Advecta Flea and Tick Dog Shampoo
Advecta Flea and Tick Spray for Dogs
Bayer Advantage Flea & Tick Treatment Spray for Dogs
Bio Spot Active Care Flea & Tick Dog Shampoo
Bio Spot Active Care Flea & Tick Spray
Bio-Derm BioGroom Flea & Tick Shampoo
Bio-Derm Flea & Tick Pyrethrin Dip
Bio-Derm BioGroom Repel-35
Espree Flea & Tick Shampoo
Fresh ‘n Clean Flea & Tick Conditioning Shampoo
Hartz UltraGuard Rid Flea & Tick Shampoo for Dogs with Oatmeal
Natural Chemistry De Flea Pet & Bedding Spray
Natural Chemistry De Flea Shampoo
Perfect Coat Flea & Tick Dog Shampoo
PetArmor LongLast Fipronil Flea and Tick Spray
PetArmor Plus Shampoo
PetLock Flea & Tick Dog Shampoo
PetLock Flea & Tick Spray for Dogs
Sentry Pro Flea & Tick Dog Shampoo
Sentry Pro Flea & Tick Spray
Vet’s Best 50 Count Flea + Tick Wipes
Well & Good Flea and Tick Treatment Shampoo for Dogs & Puppies
Zodiac Flea & Tick Dip for Dogs & Cats
Zodiac Flea & Tick Powder for Dogs & Cats
Zodiac Flea & Tick Shampoo for Dogs & Cats
Zodiac Flea & Tick Spray for Dogs & Cats
Then we cut any ingredients with scary side effects.
An effective flea treatment needs to use a pesticide — a chemical that kills bugs. All pesticides used in flea medication are approved by the Environmental Protection Agency, but they can still cause serious harm to humans and other pets if they’re handled incorrectly. After applying flea treatment, make sure to wash your hands and keep children from petting the dog until the medicine dissipates (usually 24 hours).
With so many options, we wanted to play it safe. So we turned to places like the National Pesticide Information Center (NPIC) and the National Center for Biotechnology Information (NCBI) to flag any ingredients with a track record of scary side effects:
Tetrachlorvinphos: According to the EPA and the Humane Society, side effects of overexposure can include nausea, dizziness, confusion, and even paralysis and death in humans, especially children. This ingredient is use in Adams, Hertz, and Zodiac flea collars.
Pyrethroids: The Agency for Toxic Substances & Disease Registration, a subsection of the CDC, says that humans exposed to pyrethroids can experience numbness, itching, burning, stinging, or tingling. On the label, pyrethroids are any ingredient that ends in “-thin” (permethrin, deltamethrin, flumethrin, etc,) and etofenprox. These ingredients are found in several types of medication from K9 Advantix, Frontline, Hartz, Sentry, and Zodiac.
If you have a cat, avoid medication with pyrethrin, a natural insecticide derived from chrysanthemum flowers. It’s safe for dogs and humans, but it can trigger seizures in cats. Our top picks happen to be pyrethrin-free, though many shampoos, sprays, and powders are not. If you have a cat that cuddles or grooms your dog, double check your ingredient labels.
Adams Flea & Tick Control Collar for Dogs
Adams Flea & Tick Spot On for Dogs
Adams Plus Flea & Tick Collar for Dogs
Adams Plus Flea & Tick Spot On for Dogs
Bayer Advantage Flea & Tick Treatment Spray for Dogs
Bio Spot Active Care Flea & Tick Collar for Dogs
Bio Spot Active Care Flea & Tick Dog Spot On Applicator
Flea Away All Natural Flea Repellent for Dogs and Cats
Hartz UltraGuard Plus Reflective Flea and Tick Collar for Dogs
Parastar Plus for Dogs
PetArmor Flea & Tick Collar for Dogs
PetLock Six-Month Collar
Scalibor Protector Band for Dogs
Sentry Flea & Tick Collar
Sentry Flea & Tick Squeeze-On
Sentry Pro XFT Squeeze-On Dog Flea & Tick Treatment
Spectra SHIELD Flea & Tick Collar
Zodiac Flea & Tick Dog Collar
We wanted spot-on that could also kill ticks.
All of our top picks needed to kill adult fleas, but we found a handful of spot-ons medications that use insecticides to target ticks too.
According to the Banfield Pet Hospital State of Pet Health 2016 Report, ticks are found in most areas of the United States. Tick-borne diseases, like Lyme disease and Rocky Mountain spotted fever, can be life-threatening. They’re much easier to prevent than treat, so it’s best to have a medication that can kill both fleas and ticks.
Activyl Tick Plus
Advecta II for Dogs
Bayer Advantage II
Bayer Advantage Multi
K9 Advantix II
PetArmor Advanced 2 Flea Treatment for Dogs
PetLock II Flea Treatment for Dogs
PetLock Max Flea & Tick Treatment for Dogs
Zodiac Spot-On Flea & Tick Control for Dogs & Puppies
And prevent new fleas from growing.
All the flea treatments on our list use insecticides to kill adult fleas. But Mike Potter, an entomologist at the University of Kentucky, says that the best way to get rid of fleas in your home is to use a combination of insecticides and insect-growth regulators (IGRs). IGRs appear on spot-on medication labels as (s)-methoprene or pyriproxyfen.
Ralph Williams, PhD, a veterinarian and public health entomologist, agreed and explained, “Insect growth regulators are chemicals that mimic natural insect hormones to prevent them from laying eggs.” We wanted a treatment that could eradicate a flea problem from the ground up, so we made sure our top spot-ons used an IGR-insecticide combo.
Parastar for Dogs
That left us with 13 flea medicines.
After narrowing down our list, we looked through scientific studies to compare efficacy of ingredients, and found they all live up to their label claims. Our top picks are the easiest to find and apply.
Advecta 3 for Dogs
Bayer Advantus Oral Flea Treatment Soft Chews for Dogs
Capstar Flea Treatment Tablets
Certifect Dog Flea & Lice Treatment
Frontline Plus Flea & Tick Treatment
PetLock Plus Dog Flea Treatment
Sentry Capguard Flea Tablets for Dogs
Sentry Fiproguard Plus
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.
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.
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, 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.
|Ingredients||What They Do||Found In|
|Cyphenothrin, fipronil, imidacloprid, nitenpyram, spinosad||Kill fleas by targeting their nervous system||Frontline, PetArmor, Sentry, Parastar, Flea5X, Certifect, PetAction, PetLock|
|(S)-methoprene, pyriproxyfen||Mimics flea hormones to prevent fleas from laying eggs and to keep eggs, larvae, and pupae from developing into adult fleas||Adams, 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 insecticides||Sentry, 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.