Which flea and tick medication is best for dogs?

To give your loving dog the happiest and healthiest life possible, they need to protect against pests and potential diseases. Fleas and ticks are two of the most common nuisances for your furry friends, causing discomfort at best and severe illness and even death.

Flea and tick prevention is an integral part of taking care of a dog, but how frequently you administer, along with what kind, will depend on your dog and the environment. Bayer K9 Advantix II Flea and Tick Prevention is a top pick for large dogs. Understanding how the medication works is key to finding the best option for your pet.

What to know before you buy flea and tick medication for dogs

Flea & tick dangers

Fleas can cause itching and scratching as dogs are allergic to their saliva. Serious cases can lead to sores and wounds that risk infection. Ingestion of fleas can cause internal problems as well, including tapeworms and anemia.

Ticks meanwhile lead to redness and swelling on the skin, and often they are carriers of Lyme disease and Rocky Mountain spotted fever, which can cause swelling joints, mobility issues and a high temperature.

Risk assessment

Fleas and ticks are active in warm and humid climates. However, they still exist in colder areas, though they may be quiet or dormant until summertime arrives. While they are typically prevalent in spring and summer, they will find warm places when the weather turns, hiding out in attics, garages or dens and lairs of wild animals.

Fleas and ticks find suitable hosts in various animals that live in city and suburban areas, like raccoons, deer, cats and possums. As they spread quickly from one host to another, you may expose your pup in dog parks, kennels or daycare. 

Age and weight

Your dog’s makeup will influence the dosage of medication that’s required. Options will feature an age and weight range that is most effective and should be strictly followed. Larger dogs require more powerful doses, while smaller pups can get by with less. Puppies under a couple of months old typically are not suitable for medication.

What to look for in quality flea and tick medication for dogs


You can administer flea and tick medication in various ways. Oral medication is given in pill or tablet form, typically alongside a meal. While some dogs are picky when taking an oral medication, most welcome it with few to no side effects. Oral options also don’t risk wearing off effectiveness.

Topical medication is also available. This is rubbed into the skin so that the body can absorb it. While quite effective, it requires the owner to use an optimal amount in the right areas and for the dog to agree to the experience.

Collars are also an option, and while they are convenient for some dog owners, they usually aren’t as effective as oral and topical applications. They can wear off more quickly and also become a nuisance to the dog. Shampoos are another form of medication. They tend to be cheaper. However, they are more labor-intensive and don’t last as long.


Flea and tick medications work in various ways, with some focusing on prevention and others dealing with fighting existing outbreaks. If your dog is free of any parasites, preventative formulas will maintain its healthy existence. A new outbreak may be best served by a formula that tackles eggs and immature parasites, while other formulas focus on ridding your dog of adult fleas and ticks.

Comprehensive and pricey options may be multifaceted, tackling parasites of all ages.


How long flea and tick medication lasts depends on the type and the brand. Most oral options should be given monthly. Collars may last a few months, though it can be hard to tell if it wears off too soon. Shampoos, meanwhile, may only offer protection for a day or two.

Note that some options will last for 30 days, and not all months have 30 days, so mark your calendar appropriately.

How much you can expect to spend on flea and tick medication for dogs

Price will fluctuate with effectiveness and duration. Most oral and topical options cost $20-$50 per dosage. Collars may range from $15-$45, while shampoos come in at under $20.

Flea and tick medication for dogs FAQ

What causes flea and tick medication to be ineffective?

A. Application of topical medication may prove weak if not wholly rubbed into the dog’s skin. For dogs with thick fur and an undercoat, this can be tricky. The skin should be soft, clean and healthy before application. Collars, meanwhile, may lose effectiveness if they get too wet. Most resist rain, but submergence can decrease its longevity.

Are there any negative side effects to flea & tick medication?

A. It’s important to monitor your dog for a few days after initially administering or applying medication. Pills may cause nausea or upset stomach, while creams can cause skin irritation in some cases. Collars can lead to irritation around the neck as well. If problems are ongoing, stop using the type of medication and consult your vet.

What’s the best flea and tick medication for dogs to buy?

Top flea and tick medication for dogs

Bayer K9 Advantix II Flea and Tick Prevention

Bayer K9 Advantix II Flea & Tick Prevention

What you need to know: This is a topical treatment for large dogs that is highly effective and works instantly.

What you’ll love: From a trusted name, this topical medication goes on easy and lasts for 30 days. It deters and kills off ticks, fleas and even mosquitos through contact.

What you should consider: It may not last a whole month, and some reactions were reported.

Where to buy: Sold by Amazon and Chewy

Top dog flea & tick medication for the money

Frontline Plus Flea & Tick Treatment

Frontline Plus Flea & Tick Treatment

What you need to know: This is a well-received topical treatment that offers quality effectiveness for a low price.

What you’ll love: It’s ideal for medium size dogs, provides 6 months of coverage for good value, is waterproof and repels and kills ticks and fleas of all life stages.

What you should consider: Topical application can prove difficult for some coats.

Where to buy: Sold by Amazon and Chewy

Worth checking out

Tevra Pet Activate II Flea & Tick Prevention

Tevra Pet Activate II Flea & Tick Prevention

What you need to know: This budget-friendly flea and tick prevention option is offered in various sizes to protect dogs against fleas, ticks and mosquitoes.

What you’ll love: The versatile protection for a low price and includes protection for four months, resists flea eggs, biting flies and lice. It is also waterproof.

What you should consider: Some dogs experienced adverse reactions.

Where to buy: Sold by Amazon


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Anthony Marcusa writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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