Pets
Best Flea Treatments for Dogs and Cats
There are three types of flea treatments available for dogs and cats. They include oral (pill) medications, topical treatments applied to the skin, and flea collars.
Common flea medications for dogs include Activyl, NexGard, K9 Advantix II, and Vectra 3D. Flea medications for cats include Comfortis, Bravecto, Cheristin, and Advantage II.
Always read the labels on flea medications before giving them to cats, because products designed for dogs are toxic to cats.
With summer in full swing, many pet owners are likely thinking about how to prevent their dogs and cats from getting fleas. While fleas are more common during warmer months, they can be a nuisance year-round if you don’t keep up with prevention. And for dogs, cats, or even people with flea allergies, these pesky parasites may cause quite the itch.
Below is a look at the different types of flea medications available for dogs and cats. We’ll also provide some guidance on which type of medication may be best for your pet, since there are so many products to choose from.
There are three primary forms of flea medication for dogs and cats. The main difference between the three flea treatments is how you give them to your pet. They are:
Those given by mouth (oral)
Those applied on the skin (topical)
Those worn around the neck (collars)
Search and compare options
Oral flea medications are given to your pet by mouth. They come in either pill or chewable tablet form and are available by prescription only. Most need to be given every month, except Bravecto, which only needs to be given every 3 months.
Common oral flea pills for dogs include:
Bravecto (fluralaner)
Comfortis (spinosad)
Credelio (lotilaner)
NexGard (afoxolaner)
Simparica (sarolaner)
It can be difficult to determine the best oral flea treatment options for cats. There also aren’t as many options compared with what’s available for dogs.
Available oral flea medications for cats include:
Comfortis
Credelio
Program (lufenuron)
Cat allergies: Cats can have allergies to fleas and other things, just like dogs. Learn what you need to know about allergies in cats and how to help an itchy feline.
Mites can be dangerous. Read one dog owner’s experience with this preventable parasite and how their pet was treated.
Got a flea bite? If your pet has fleas, then you probably know you can get bitten by these pests, too! Here’s what flea bites look like on humans.
Some oral flea medications for cats — such as Program — are also available as an oral liquid. It may be easier to give your cat liquid medication instead of a pill. But if your cat really doesn’t like oral medication, your best bet may be a topical medication (see below).
Depending on the specific brand of oral flea medication you use, it may need to be given to your pet with food or on an empty stomach. Flea medications that can be given with food are usually easier to get your pet to take.
For most dogs, hiding the pill in peanut butter, squeeze cheese, a banana, or bread will do the trick.
Topical flea medications are applied directly to your pet’s skin. Topical flea medications for dogs and cats include:
Advantage II (imidacloprid / pyriproxyfen)
Bravecto (fluralaner)
Cheristin (spinetoram)
Frontline Plus (fipronil / methoprene)
K9 Advantix II (imidacloprid / permethrin / pyriproxyfen)
Revolution Plus (selamectin / sarolaner)
Vectra 3D (dinotefuran / pyriproxyfen / permethrin)
Just like oral medications, most topical flea medications should be given monthly. If your pet is prescribed Bravecto, it only needs to be applied every 3 months. Most of these medications are available over the counter and do not require a prescription from your vet.
When giving flea prevention medication to cats, always read the label and make sure it’s approved for cats. Flea medication for dogs can be very toxic to cats and can even result in death.
To apply topical flea medication, use your fingers to part your pet’s fur and apply the product on:
The skin of their neck
In between their shoulder blades
Along their spine
When applying flea medication on a cat, just put it on the top of their neck and in between their shoulder blades. Since cats are avid groomers, you want to put it in a spot they can’t reach with their tongue.
If your cat licks off some of the flea medication, they may drool for a few minutes. As long as you used a cat-only flea medication, this is usually just due to the medication’s taste. But if your cat swallowed the entire tube of medication or got a dog-only flea product, then take them to the vet immediately, and call a pet poison hotline.
Make sure not to bathe your pet for at least 48 hours before or after you give them a topical flea product. This will make the medication less effective.
If neither oral nor topical flea medication is right for your pet, you might want to try a flea collar. Not all flea collars are created equal, and many of the older ones aren’t as effective as they used to be. Flea collars do not require a vet’s prescription.
One popular flea collar for dogs and cats is Seresto (flumethrin / imidacloprid). It can keep fleas away for up to 8 months before it needs to be replaced.
But there have been some safety concerns about Seresto and its potential to cause seizures in pets. The Environmental Protection Agency (EPA) reviewed safety concerns about Seresto, and in 2023 it decided the collar was generally safe for pets.
But the EPA found some cases where pets died because the safety release on the collar didn’t work as expected. After the EPA’s review of Seresto, the manufacturer agreed to improve the safety of the collar. Even with these concerns, keep in mind that negative reports about Seresto collars are very rare.
Seresto is the only available flea collar for cats. There are other flea collar options for dogs, including:
Preventic (amitraz)
Scalibor (deltamethrin)
If you use a flea collar for your pet, make sure it fits them and touches their skin so it works correctly. The collar should fit snugly around your dog or cat’s neck. But you should also be able to fit two fingers between your pet’s neck and the collar.
In 2025, the FDA approved Bravecto Quantum, a flea and tick medication that lasts for up to 12 months. The medication is given as an injection at your veterinarian’s office. It’s available only for dogs who are at least 6 months old.
If you’re concerned about remembering your dog’s monthly flea medication, Bravecto Quantum may be a good option.
Keep in mind that like other Bravecto products, Bravecto Quantum contains an isoxazoline medication. In some dogs, isoxazolines may cause neurological side effects, such as:
Tremors
A wobbly or drunken walk
Your vet’s office may recommend prescription combination products that can take care of fleas, ticks, heartworm disease, and internal parasites all in one oral or topical medication.
A combination medication can be much easier when your pet needs protection against several pests, because you only have to give your pet one medication for all of them. It may also save you money in the long run.
Examples of combination flea, tick, heartworm, and internal parasite medications include:
Revolution (selamectin)
Selarid (selamectin)
Advantage Multi (imidacloprid / moxidectin)
Sentinel Spectrum (milbemycin oxime / lufenuron / praziquantel)
If your dog takes one of the combination products, you usually need to make sure they have a heartworm test every year to continue taking the medication.
The best flea medication for your cat or dog will depend on what’s easiest to give to them. For dogs or cats who don’t do well with oral medication, a topical or collar flea treatment may be your best bet. On the other hand, if your pet has sensitive skin, your best option may be a pill.
In addition, some pets have sensitive skin or a history of breaking out or losing fur in the areas where topical flea medication was applied. They might also be better served with an oral flea medication.
If you have a cat who loves to groom other pets at home, prevent them from doing so for 24 hours after you apply topical flea medication. If you can’t prevent them from grooming, then the best option for all the pets in your home may be oral flea medications instead.
If your cat is picky and tends to spit out pills hidden in wet food or pill-hiding treats, oral cat flea medications might not be a great choice for them.
And if your pet doesn’t take medication by mouth very well, or if they tend to get sick with anything new in their diet, consider using a topical flea medication.
Several flea medications are available over the counter (OTC) for cats and dogs without a vet’s prescription. These include:
Capstar
Effipro
Frontline Plus
K9 Advantix II (not for cats)
PetArmor
Preventic collar
Seresto collar
But keep in mind that OTC flea products don’t work as well as prescription flea preventives. Ask your veterinarian whether your dog or cat will do better with a prescription product instead.
You can use oral and topical flea medication together, but you usually don’t need to. Generally, if your pet is already on one type of flea prevention, it’s not necessary to use a second kind unless your vet recommends it.
Your vet may suggest using two types of flea medication if your pet has a severe allergy to fleas.
Pets with flea allergies can lose fur, become extremely itchy, and get very red and inflamed skin from the bite of just a single flea. Some of these pets need flea prevention medications every 2 weeks. And many vets recommend alternating the doses between topical and oral medications.
Again, these are only in extreme cases. So it can be safe to use the two medications together, but it’s usually not necessary. Always talk to your vet before using more than one flea medication.
Flea medications for dogs and cats are generally safe. Occasionally, a dog or cat may be a bit sensitive to one. For instance, topical medications may cause hair loss or mild irritation in the area where they were applied on your pet. Or, if your dog or cat has a sensitive stomach, the oral flea medication may cause them to be nauseous or vomit.
If you notice any of these signs or any other change in your pet after giving them a flea medication, let your veterinarian know. They will want to keep an eye on your pet’s health and potentially report any side effects to the manufacturer of the medication.
When starting your pet on a new oral flea medication, try to give it to them on a day when you can be around to watch for potential issues. If possible, don’t give your pet any other medications or new food that day, either. This way, if your dog or cat has a problem, you’ll know it was most likely due to the flea medication and not something else.
No, not really. There are many suggested natural alternatives to flea medications out there. However, they do not work as well as the manufactured products that have gone through safety and effectiveness testing.
Also, many of the supposed natural alternatives to prevent fleas can be toxic to your pets. For instance, some people suggest using garlic, and others recommend essential oils to ward off fleas. But garlic can cause severe anemia in dogs, while essential oils can cause neurological issues and liver failure in cats.
If you prefer natural alternatives for flea control, talk with your veterinarian and let them know. They can work with you to find a flea control option that is safe and effective for your pet and more natural for your home.
Both topical and oral flea medications can be effective when given to your pet on schedule. Look for prescription topical or oral medications, which are typically more effective. Otherwise, the best option for your dog or cat will come down to personal preference.
Cats or dogs who don’t take pills well may do better with a topical medication applied to their skin. Pets with sensitive skin may do better with a pill flea medication instead of topical. Ask your veterinarian for guidance on what will be best for your pet.
Both topical and oral flea medications can be effective when given to your pet on schedule. Look for prescription topical or oral medications, which are typically more effective. Otherwise, the best option for your dog or cat will come down to personal preference.
Cats or dogs who don’t take pills well may do better with a topical medication applied to their skin. Pets with sensitive skin may do better with a pill flea medication instead of topical. Ask your veterinarian for guidance on what will be best for your pet.
Flea medicines work by targeting cells or nerves in the fleas, depending on the type of medication. As a result, the medication kills fleas fast. Many flea preventives also kill other parts of a flea’s life cycle, ensuring that all the fleas are gone from your pet.
No, you cannot use dog flea medicine on cats. Dog flea medications are very toxic to cats. If your cat accidentally gets a flea medication for dogs, call a pet poison hotline or take them to an emergency hospital right away.
It’s also best not to use cat flea medications on dogs. Cat medications are designed to work best for cats, so they won’t work as well on dogs.
While fleas are common and a nuisance, they are definitely manageable and preventable with the right medications and control measures. Oral, topical, and collar flea medications, especially the newer ones, are usually safe and effective for your cats and dogs. But it is always best to check with your veterinarian to determine the best flea prevention option for your pet and lifestyle. And don’t ever give your cat a flea medication that’s intended for dogs.
American Veterinary Medical Association. (2023). EPA confirms registration, safety of Seresto collar.
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British Columbia Society for the Prevention of Cruelty to Animals. (2024). Dangers of using your dog’s flea & tick medication on your cat.
Cohen, A. (n.d.). Flea and tick prevention. Cornell Richard P. Riney Canine Health Center.
Fisara, P., et al. (2023). Year-round efficacy of a single treatment of fluralaner injectable suspension (Bravecto Quantum) against repeated infestations with Rhipicephalus sanguineus (sensu lato) and Ctenocephalides felis in dogs. Parasites & Vectors.
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Ihrke, P. J. (2006). New approaches to common canine ectoparasites. World Small Animal Veterinary Association World Congress Proceedings, 2006.
Pet Poison Helpline. (n.d.). Garlic.
Stanneck, D., et al. (2012). Evaluation of the long-term efficacy and safety of an imidacloprid 10%/flumethrin 4.5% polymer matrix collar (Seresto) in dogs and cats naturally infested with fleas and/or ticks in multicentre clinical field studies in Europe. Parasites & Vectors.
Tater, K., et al. (2019). Client flea/tick chart for cats. Veterinary Partner.
Tater, K., et al. (2019). Client flea/tick chart for dogs. Veterinary Partner.
The VIN Dermatology Consultants. (2019). Flea and tick control products for dogs and cats. Veterinary Partner.
U.S. Environmental Protection Agency. (2025). Seresto pet collar review.
U.S. Food and Drug Administration. (2023). Fact sheet for pet owners and veterinarians about potential adverse events associated with isoxazoline flea and tick products.
U.S. Food and Drug Administration. (2025). FDA approves first long-acting flea and tick treatment for dogs.
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