Seresto vs Frontline: What Woof Is The Difference? (We Asked A Vet)

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seresto vs frontline plus
We’re all thankful to have the beautiful weather at the moment but what none of us want are the little hitch-hikers that come to hang out on our dogs. Yep, it’s flea and tick season!
Fleas are primarily a nuisance causing irritation or even an allergic skin flare in a prone pup and are known to snack on the occasional human which can be uncomfortable and itchy. Luckily, the list of flea-transmitted diseases is short, though they can pass diseases that can affect us humans: Bartonellosis aka Cat scratch fever, Yersinia pestis aka Plague and Rickettsia typhi aka Typhus fever. Canine tapeworm can also be spread between dogs by fleas. canine tapeworm, however can be transmitted through flea bites.
Ticks on the other hand are well known for their disease spreading capabilities, especially Lyme disease, caused by the bacterium Borrelia burgdorferi. While infections are uncommon, this can be a debilitating disease and does affect humans so extra precautions should be taken to minimize risk to both our fur-iends and ourselves.
As dog owners, we’re bombarded with so many products and advice that it makes our heads spin; what product is the best?! Well, scroll no more, in this post we’re going to provide you with an in-depth analysis of two commercially available products – Seresto vs Frontline Plus.
This comparison will help you to choose which product will suit your dog the best.
What do Seresto and Frontline Plus actually DO?
Seresto and Frontline Plus are both commercial, veterinary-formulated products to control flea, tick and chewing lice infestations. Infestation with lice is incredibly rare except in dogs that have severely compromised immune systems. So, let’s get a little bit more in depth:

Seresto Collar Review

Our Rating:


Price range: $$

Seresto Flea and Tick Collar for Dogs


Seresto collar is available as a unique ‘collar’ application where you simply pop the collar on your fur-iend and forget about it for up to 8 months. Ensure the collar is fitted suitably (can get 2 fingers underneath comfortably) and check it regularly to ensure it’s fitting well, just as you do with your dog’s regular collar.

Seresto collars are available in 2 sizes for dogs, up to 18lbs and over 18lbs weight. It may seem unusual given how much narrower the weight ranges are for other products but part of this is because you can trim the collar to a suitable size for your pooch.

As the whole collar is impregnated, when you cut the excess off you are reducing the amount of medication to which your dog is exposed to an appropriate dose for their size.

What does it kill?

Seresto has been proven to kill fleas on your dog within 24 hours and once the active ingredients have been absorbed into your dog’s fur, ticks are actively repelled without even having to bite to ingest the product.

Flea larvae are also targeted in your dog’s bedding while all stages of the ticks’ life cycles are targeted. Chewing lice may take up to 7 days to be eliminated from your dog. So, if your dog has an active infestation with lice your veterinary surgeon may advise you about initial treatment prior to using the collar.

Seresto collars can also reduce the risk of your dog becoming infected with Leishmania infantum (Leishmaniosis) caused by bites from sand flies. Though Seresto isn’t licensed for the control of mites such as Sarcoptes scabei, a study in 2012 did show that the medications within a collar do work to kill mites, though at a much slower rate of several weeks so again, your veterinarian will likely prescribe an alternative, faster acting treatment for an active infestation (Stanneck et al., 2012).

How does it work?

The ingredients in Seresto work by being absorbed into the body of the pest and binding to certain receptors which prevent nerves from communicating thus causing paralysis and death.

How long does it last for?

Seresto collars have been proven to last for up to 8 months in most conditions. Being water resistant, your pup can go swimming and you don’t need to remove the collar to bathe your dog though too much water or excessive shampooing may reduce the duration of efficacy.

This seems to mostly affect its activity against fleas. Clients have asked if they can just use the collar for a short period of time and save it for use months later; this isn’t recommended as if it’s not on your dog then it’s not protecting your dog from fleas and ticks.

Once the packaging has been opened, the collar will constantly release the medications over a sustained period of time, so it won’t last longer than 8 months whether or not it’s on your pup.

What are the active ingredients in Seresto?

How are the ingredients in Seresto delivered?

The collar has been impregnated with both active ingredients which are then slowly released in a controlled manner onto your fur-iend’s skin and coat.

These then spread across the entire body through the lipid layer within your dog’s skin. Another plus with using these collars is that they are odorless and non-greasy.

How long does it take for Seresto to start working?

The Seresto collar will start to release the ingredients once applied to your pooch’s neck and has been proven to kill fleas within 24 hours.
One study indicated that action against ticks may be seen in as little as 6 hours after application with these ingredients (Stanneck, et al., 2012).
The producers of Seresto collars advise that you remove any attached ticks when you apply the collar as it may take up to 48 hours to kill them and so disease transmission is a risk until that time.

Are there any safety risks or possible side effects of Seresto?

As with all products there are some risks, though adverse effects tend to be rare and mild if they occur when using Seresto collars. A question I’m often asked about is the safety of the collar to members of the dog’s human and fur families.
It’s true that the active ingredients can cause signs of sickness in humans and dogs but the doses required far exceed those released by the collar. If your pup chews on their collar, they may have short term Gastrointestinal Distress including vomiting, abdominal pain and diarrhoea.
As with all collars, there can be a risk of your dog getting caught on something but Seresto collars have a “breaking point” and quick release for smaller dogs which means that if your pup’s collar catches on something the collar will break to prevent injury to your dog.

Side effects of using a Seresto Collar:

What We Like About Seresto collar

What We Don't Like About Seresto

Veterinary Opinion

Seresto collars are particularly popular with clients whose daily jaunts with their canine companion involve woodland hikes. These collars are convenient; just pop one on your pup and you’re good to go for almost 8 months.
Side effects are thankfully very rare and tend to be short-lived and mild, so as a vet they are very safe when used properly.
While they are expensive to purchase, if you compare the cost with 8 months worth of some other products they are competitive.
If your fur-baby is a water-pup or bathed frequently (more than once per month) then the duration of efficacy of these collars may be reduced. In these cases after 5 months use, monitoring is needed to ensure your pup isn’t picking up fleas again.
You can remove your dog’s Seresto collar when bathing to try maintain its efficacy, but remember your pooch could pick up parasitic passengers while the collar is off so don’t forget to put it back on once their coat is dry.
Seresto collars do repel ticks but if your fur-iend is in an area with a high population of ticks they may pick up one or two. Any that do clamber onto your pooch should be eliminated on contact but there have been cases where a tick was able to attach so the risk of disease transmission isn’t completely eradicated but again, this is very rare.

Frontline Plus For Dogs Review

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Price range: $$

Frontline Plus Flea and Tick Treatment


Frontline Plus for Dogs is a topical product to control flea and ticks. Easily administered using the pre-measured snap-top pipette onto the back of your pup’s neck, between their shoulder blades; just part the hair and squeeze onto the skin.
Frontline Plus should be applied once dog month onto the skin, NOT just onto your pup’s fur. You should apply all the liquid in a single spot, NOT along your pup’s back. You don’t want your pup to be able to lick the product off their coat after application.
Also, I advise not to bathe your pup for up to 48 hours after application (or allow them to swim) to ensure optimal absorption of the medication into the skin.

What does it kill?

Frontline Plus for dogs kills all stages of the flea life cycle while also preventing eggs and larvae from developing to the next stage.
Existing flea infestations are killed within 12 hours of application and continues to prevent rebound infestations for 30 days. Ticks don’t escape either as this product kills adults, nymphs and tick larvae. Frontline Plus also kills chewing lice and some mites.

How does it work?

The specially formulated liquid is rapidly absorbed into your fur-iend’s skin and stored within their oil glands at the base of their fur.
Over 30 days, the ingredients are released through your dog’s hair follicles to continue protection. Fleas and ticks that come into contact with your dog don’t even have to bite in order to be killed.

How long does it last?

Frontline Plus for Dogs will continue to protect your pup for 30 days after application. You can wash your pup or go swimming loads because Frontline Plus is waterproof after 24 hours, so it doesn’t get washed off between applications. 

What are the active ingredients in Frontline Plus?

How are the ingredients in Frontline Plus delivered?

The pre-measured liquid is rapidly absorbed into your dog’s skin and then slowly released from hair follicles to protect your pup from fleas and ticks.

How long does it take for Frontline Plus to start working?

Frontline Plus has been shown to start killing adult fleas approximately 4 hours after application and will kill 100% of fleas within 12 hours.
If your pooch and house is suffering from an established infestation, I always advise my clients to launder and vacuum anywhere your dog sleeps and carpeting and to consider using a product specifically designed for the environment to help speed up the elimination of the infestation.

Safety, risks and possible side effects of Frontline Plus

All products have risks, but adverse effects of Frontline Plus are thankfully rare. Some dooga may develop some temporary redness and itching following application of the product. These signs tend to be mild and resolve within a day or so.
It’s incredibly rare for these signs to persist though if your dog experiences severe irritation you should contact your veterinarian as treatment may be necessary.
Rarely, this product may cause irritation of your skin or eyes so as with all products, avoid spilling or getting into your eyes and always wash your hands after use. I also advise my clients to apply this product just before bedtime so that nobody is stroking the dog until the product has fully absorbed.

What We Like about Frontline Plus

What We Don't Like About Frontline

Veterinary Opinion

Frontline Plus is a popular choice for many of my water-pup patients who can’t pass a puddle without attempting a paddle.
It’s waterproof and it’s efficacy isn’t reduced by environmental factors, in fact sunlight may actually make the active ingredient, fipronil more toxic to insects (Gupta, 2007). That’s a win in my book! Spot-on products like Frontline Plus are fantastic for growing puppies to ensure that they’re fully covered against fleas and ticks.
While the monthly applications don’t suit everyone, lots of veterinary practices have automatic reminders for when your fur-iend is due their next treatment.

While it’s rare, some dogs may have reactions to flea treatment particularly if they are on medications or are ill so always discuss this with your vet before administering.

Collar vs Spot-on:  The most obvious difference between these products is the fact that Seresto is available as a collar that remains on your dog for the duration of it’s activity while Frontline Plus is a single application of liquid to your dog’s neck that is then stored within the oil glands of your dog’s skin.
Duration of action:  Another big difference between these is how long each product remains active: Seresto can continue protecting your dog from fleas and ticks for up to 8 months while each application of Frontline Plus is active for just 30 days.
Water resistance: Summer is a time for swimming and your dog needs a product that will protect them even after a cooling dip. Seresto collars are advertised as water-resistant, this means that your dog will continue to be protected as any medication that is washed off during their swim is rapidly replenished by the collar. However, this also means that the collar may not remain effective for the full 8 months; its efficacy can be reduced to 5 months. Frontline Plus on the other hand is waterproof meaning that your dog remains protected for the full 30 days.

The crunch: Do these products work? Yes, they do work. Both products have been clinically proven to target all stages of the flea and tick lifestyles to eliminate and prevent further infestations. In fact, fleas don’t even have to bite your dog to be killed which is a big plus in preventing disease transmission. There have been some anecdotal reports of flea resistance to fipronil, but this is unlikely to affect most dogs.

The bottom line, pricing for both of these effective products will vary depending on where you purchase. Ballpark figures for Seresto collars for both large (>18 lbs) and small dogs (<18 lbs) are in the region of $65 which works out at approximately $8.50 per month.
Frontline Plus is available in packs of three, six or eight pipettes with differing doses depending on dog size. Six doses of the small dog pipettes (5-22 lbs) costs around $65. This works out at $11 per month for a small dog but the price per month will increase with dog size. Price comparison would show that Seresto works out as the cheaper option.

Price comparison would show that Seresto works out as the cheaper option. 

Seresto vs Frontline Plus What Are the Differences

Does my dog really need flea and tick medication?

The short answer is, yes! Even if your dog doesn’t have Flea Allergy Dermatitis (FAD), they need protection against these tiny jumping parasites. Fleas and ticks are ubiquitous in almost all environments and these bugs don’t discriminate between what animal they choose to make their new home.

Aside from the irritation and discomfort these parasites cause dogs, they are also responsible for transmission of a range of diseases throughout the world and some of these diseases can be fatal. All dog’s need flea and tick preventatives at appropriate intervals suitable to their environment and exposure risks.  

How old does my puppy need to be before using these products?

Puppies older than 8 weeks (7 weeks for Seresto) or weighing over 4.4lbs can have either of these products applied. I tend to advise using a topical product such as Frontline Plus for these tykes as it allows for accurate dosing for your rapidly growing little pupper. Pups grow so fast and the Seresto collars are designed to be trimmed to fit so if using these you may find that your dog outgrows their collar too fast.

My dog is pregnant/nursing puppies but she has fleas, can I still use one of these medications?

Frontline Plus is suitable to use in pregnant or nursing bitches, which will help control flea infestations when you have puppies too young to receive medications. Conversely, it’s advised not to use Seresto collars on pregnant or lactating bitches.

My dog is sick or has recently been diagnosed with a long-term illness, can I use these medications?

If your dog is sick, don’t apply any products until they are recovered. If your dog has a chronic illness then discuss with your veterinarian what product is best suited for them.

Can I mix and match flea treatments?

No, mixing flea treatments or repeating administration sooner than is advised can be detrimental to your dog’s health and increases the risk of them having an adverse side effect.

What’s the expiration for these products?

Seresto remains suitable for use once unopened for 5 years after manufacture. These collars should be stored at room temperature before use. Frontline Plus has no published expiration dates and should be fine to use once the pipettes have been stored at room temperature.

Understanding Fleas & Ticks

A flea’s life starts with tiny eggs that aren’t really visible to the naked eye. The adult female flea lays these in your dog’s fur, their bedding or any cosy furnishings and carpeting. A female can lay up to 2,000 eggs in her lifetime at a rate of approximately 50 eggs per day. These eggs hatch within a week into larvae that love cosy cushions, carpets and dog beds. Following pupation, usually around three weeks later, the adult fleas sense the vibrations of a new host and hitch a ride, have a blood meal and start the cycle all over again. So, with such a short life-cycle you can see how an overwhelming infestation can occur in just a short period of time. This is even worse if your dog has Flea Allergy Dermatitis (FAD) where even just a single bite from a flea can send them into a scratching frenzy which won’t settle.

Ticks have an extra stage to their life plan and there are a huge number of species throughout the world and are well known for spreading diseases. These diseases include Lyme disease, Rocky Mountain Spotted Fever and Babesiosis, all of which are rather nasty. Ticks tend not to cause mass infestations the way fleas can and this is, in part, due to their longer life cycle of between 1-4.5 years. Female ticks lay their eggs in the environment, which is by and large outdoors; she can lay up to 2,000 eggs at one time. When the conditions are right, larvae hatch from the eggs and will ‘quest’ (yes, that’s the term) for their breakfast, usually a small mammal. Ticks can’t jump so they will climb vegetation and grasp onto a host as it passes by. The larval stage lasts 4 days before they drop off the host to moult. Nymphs emerge from this up to a year later depending on weather conditions and seek out larger hosts for another blood snack where they gorge for up to 6 days before repeating the process to emerge as an adult on the hunt for an even larger host such as a deer, a pooch or even a person. Male ticks will intermittently feed whilst mating with females on the same host. The adult female however will constantly feed for up to 11 days before dropping off to find somewhere cosy to lay her eggs and kickstart the cycle all over again. 

Both bugs are most active in the warmer months, though I have treated dogs in winter too. As we always say, “Prevention is better than cure” so trying to minimize the risk to our dogs should be the primary goal. For fleas this includes vacuuming the carpets and upholstery along with regular laundering of your pup’s bedding while for ticks it’s more focused on regular, careful inspection of your pooch’s body and removal of ticks after a romp in the woods or anywhere there is longer grass. Don’t forget to check yourself when you’ve been outdoors too as tick bites aren’t always painful but can cause problems for humans.

These measures can only control part of the issue with these tiny terrors, and long lasting preventatives can provide us with that extra peace of mind that our dog is protected. Selecting a product depends on your preference, your pup and lifestyle, so here we’re discussing the use of Seresto vs Frontline Plus to help you make the best choice for your fur-iend.

The thoughts of a flea infestation gives most of us a sudden need to scratch. These little insects have evolved to hide amongst the dense fur of most dog breeds, and while it’s normal for your pup to experience the occasional itch if you notice any of the signs below then your pup may be suffering with fleas.
Fleas are tiny, dark creatures but adults are visible to the naked eye. If you part your dogs hair you may be able to see them scurrying around. Fleas can be found anywhere on their host but tend to be more visible around the base of the tail and lower back, along the belly and in the folds of a pet’s ears and neck.
Not finding live fleas doesn’t mean your pup hasn’t been infested. A handy trick is to buy a flea comb and brushing through your dog’s fur.

These combs pick up fleas and flea dirt; flea dirt is essentially flea poop and looks like black speckles on skin or white fur. After combing through, gently wipe the comb against a pale, damp cloth or paper towel, if your dog has fleas then you may see reddish-brown or black streaks on the cloth which is digested blood and confirms the presence of fleas. 

Final Thoughts

seresto vs frontline final thoughts
We all adore our fur-babies and want them to live long, happy and healthy lives. Part of this includes parasite prevention and your veterinarian will only advise what they feel is best for you and your dog so I urge you to seek their advice if you’re not sure whats best for your pup.
My preference on Seresto vs Frontline Plus is to use Seresto collars on my dog as she spends a lot of time in wooded areas and loves to explore; however with my previous dog who was a complete water-baby I preferred topical medications.
Seresto collars are the only preventative that can actually repel ticks without them having to bite first which virtually eliminates the risk of disease transmission. However, if you have a lactating bitch or young, growing puppies Frontline Pro would be more suitable for these dogs.
Fleas and ticks can be a year round problem in many parts of the world though they tend to be a bigger concern in the warmer months.
Choosing a preventative that suits you and your dog’s lifestyles is important, you don’t want to constantly be wondering if your pet is suitably protected.
Seresto collars are non-greasy with no smell and can provide protection for your dog for up to 8 months while Frontline Pro is available in easy to use, single dose ampoules that give protection for 30 days.

Adverse reactions can occur with any product though these tend to be very mild. If your dog has sensitive skin, your veterinarian will be able to advise you on the most appropriate product for your pup. 

Photo of author
Since graduating from Dublin, Ireland in 2013 with an honors Veterinary Medicine degree, Edele has enjoyed working with as many species of animal as possible. Edele is currently working in clinical practice while studying towards Advanced Practitioner status with the RCVS in the UK. Passionate about education and writing, Edele’s goal is to maximize the pet-owner bond and welfare through education accessible to everyone. Never found without her middle-aged Weimaraner, Purdy (who still thinks she’s 18 months old), Edele spends her limited time outdoors with her horses, hiking and traveling home to Ireland to spend time with family.

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