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Seresto Dog Flea Collar – Review, Ingredients, Pros & Cons

Written by Viena
Viena is passionate about all sorts of domesticated pets. They have written dozens of articles across the web.
Published on
Sunday 14 June 2020
Last updated on
Tuesday 9 May 2023
seresto dog flea collar
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Seresto dog flea collar is a vet-recommended device that helps repel flea and tick from your pets. It is one of the popular pet products from Bayer Animal Health. Bayer manufactures healthcare products for humans, animals, and plants. Also, it ensures the well-being of animals by providing innovative solutions in pet protection.

Ticks, leas, and lice are the most common problems in dogs. These unpleasant insects cause discomfort and sickness to our lovely fur babies. Also, most pet owners use Seresto flea collars to fight against these pests. This article is a comprehensive Seresto flea and tick collar review highlighting the pros, cons, and noteworthy points.

How Do Seresto Flea Collars Work?

There are various things you can use to fight against dog fleas and lice. You can give your pets chewable tablets, powder, shampoo, and even topical ointments or solutions. But, aside from these products, you can also use Bayer Seresto flea and tick collar. This easy-to-use, no-mess solution contains active ingredients that make it useful in controlling flea problems.

The collar gradually and continuously emits the stored active ingredients once your pet wears it. Eventually, these compounds spread on the dog’s coat from head to toe and tail. Then, the fleas and ticks become paralyzed and die once they get into contact with the fur. It also kills lice and sarcoptic mange that cause irritation and infection on a dog’s skin. Lastly, the ingredients found in the collar can also kill parasites even in their larvae stage. And, the effectiveness of the Seresto dog flea collar in controlling fleas and ticks can last up to eight months.

how seresto flea collars work
The Seresto dog flea collar is an easy-to-use no-mess solution to fight off ticks and fleas!

Active Seresto Ingredients

Bayer’s Seresto flea and tick collars contain two main active ingredients. These are the imidacloprid and flumethrin. These two substances prevent and quickly kill ticks within 24 hours and continue to repel infestations for eight months.

Imidacloprid (10%)

Bayer Seresto collar contains 10% imidacloprid that kills adult fleas and their larvae. Imidacloprid is an insecticide that belongs to the class of neonicotinoids. Also, this compound attacks the central nervous system of insects that results in their paralysis and eventual death. Hence, it is one of the extensively used insecticides for both plants and animals in the world.

But, pet owners need not worry much about imidacloprid since it strongly affects the nervous system of insects more than mammals. Thus, it is more toxic to insects than humans. However, it is still wise to take precautionary measures and consult with your veterinarian when dog collars with imidacloprid. Further, it is not advisable to use the Seresto flea collar on puppies younger than seven weeks old. Some other uses of imidacloprid aside from flea control are the following:

  • Termite prevention
  • Garden pest control
  • Protection of trees from wood-boring insects
  • Preservation treatment of lumbers
  • Control of insects that damage crops
  • Protection of homes from termites, cockroaches, carpenter ants, and other insects

Flumethrin (4.5%)

The Seresto flea collar from Bayer has 4.5% flumethrin that repels and kills all life stages of ticks. Besides, flumethrin is an insecticide belonging to the pyrethroid class. Aside from protecting pets against fleas, flumethrin is also used in Bayvarol. Beekeepers use the Bayvarol to fight against Varroa mites.

Also, flumethrin disrupts nervous impulses, thus causing paralysis to insects. At low concentrations, it can also make arthropods and insects to suffer from hyperactivity. Whereas, at a higher level, this substance can kill them. Normally, dogs, livestock, and birds can tolerate the toxicity of flumethrin.

However, fishes and other aquatic animals are more sensitive to pyrethroids than dogs. Thus, it is advisable not to dispose of materials containing flumethrin into bodies of water. Other possible effects of this compound are the following:

  • Ataxia or uncoordinated movements
  • Tremor, trembling or shaking movements
  • Paresthesia (tingling, tickling, or prickling skin sensation)
  • Exhaustion
  • Hyper-salivation or drooling
  • Vomiting
  • Diarrhea
  • Urinary incontinence
  • Difficulty in breathing
  • Cramps or spasms
  • Dermatitis with skin reddening and itching

What Do Seresto Dog Collars Work Against?

The innovative technology in the Seresto dog collar enables it to control the release of chemicals on your pet’s coat. Also, these small doses of the active ingredients spread and stay on your pup’s body for up to eight months.

Similarly, it helps fight against the following parasites.


Seresto flea collar helps control and prevent flea infestations. It is not enough to get rid of the existing fleas and larvae on your pets. More important is to prevent new insects from infecting your pup’s skin. The Bayer Seresto collar does all of these. It gets rid of fleas and larvae and prevents new fleas from coming back at the same time.

Fleas are external parasites that live on the skin of domestic dogs and cats. These parasites feed on your dog’s blood. Thus, keeping your pets free from fleas is vital.

Consequently, dogs suffer severe itching in areas where fleas dwell. Also, aside from scratching, your pup may bite itself; thus, causing redness and inflammation of the skin. At the same time, they can transmit tapeworms and may cause dog anemia in extreme cases. Likewise, flea allergy dermatitis develops on dogs that are allergic to flea saliva. It can cause bald spots, hot spots, and smelly skin.


Ticks are common on dogs. They are parasite arachnids with eight legs and no antennae. Unfortunately for you and your pets, ticks attach themselves firmly onto your pup’s skin when sucking blood. Also, these parasites can feed not only on animals but on human blood as well. They can carry and transfer diseases, cause weakness, weight loss, and even death of your pets. Thus, treating and preventing ticks is essential to maintain your and your dog’s health.

There are different types of products to help you with dog tick problems. One of which is the Seresto dog flea collar. It is wise to consult with your veterinarian when it comes to keeping your pooch tick-free. Thus, it is helpful if you regularly check your pets for ticks so that you can get rid of them early.


When it comes to dog lice, there is both good and bad news. The good news is that you cannot get lice from your dog, and vice versa. Human lice will not thrive on animal blood. However, there is more bad news than there are good ones. First, lice cause itch, pain, inflammation, and eventually hair loss. These insects are small, flat, and wingless that live on the hair of mammals and feathers of birds. They hang on to their hosts’ hair using their six legs with hook-like claws at each end.

Secondly, some eat dog skin debris, called chewing lice. It is commonly found in regions with a tropical climate. On the other hand, this sucking pest needs blood to survive. These vile parasites have a pointy sharp mouthpiece for sucking blood. Louse infestation can also lead to serious dog health issues.

So, you must be able to recognize and treat lice immediately. What you can do is to use flea combs to remove lice from your dogs. Also, the Seresto dog flea collar is one of the best ways to prevent and get rid of annoying dog lice.

Sarcoptic Mange

Sarcoptic mange in dogs can often be treated by scabicide. It is a drug that can kill mites that causes itchiness on animals. However, this type of treatment needs the supervision of your veterinarian. A much easier way to treat this disease is by using a Seresto dog flea collar. Even though there is currently no known treatment, immediate detection and treatment of mites will be best for your dogs. Also, a healthy animal immune system can help avoid a recurring problem.

Sarcoptic mange is extremely contagious; thus, immediate management is necessary. There may be instances when you will need to quarantine your dog to prevent infecting other pets and humans at home. Below are the symptoms if your pooch has these nasty mites:

  • Severe itchiness and scratching
  • Skin rashes
  • Formation of crusts on the skin
  • Hair loss

Benefits of Seresto Collars

The Seresto collar for dogs is an innovative product from Bayer. It safely and effectively protects your pooch from fleas, ticks, and lice. Thus, keeping your fur baby healthy and free from parasites. There is the Seresto for large dogs, which is ideal for pooches that weigh more than 18 pounds. Likewise, you can use the Seresto for small dogs for pups that weigh less than 18 pounds.

Eight-Month Flea and Tick Prevention

With the Seresto dog flea collar, you can be sure that your fur babies are protected from harmful parasites for an extended period. The collar’s sustained release technology provides constant protection on your pet’s coat for up to eight months. It can keep your adorable pooches from the annoying and disturbing itch and pain from mite bites without any worries on your part. Even if it gets muddy, the dirt will not have any effect on the efficacy of the Seresto flea collar. Moreover, you don’t need to remove it when your pet needs a bath or goes swimming since it is water-resistant.

You can be sure that using a Seresto dog flea collar for your furball is safe. It is because veterinarians recommend it. It is even safe for use on puppies aged seven weeks or older. But, you must prevent your pets from chewing the flea collar. Although it cannot be fatal, it may still cause mild gastrointestinal discomfort on your pup. Finally, don’t worry if you see some ticks on your dog’s coat even if it is already wearing the flea collar. The active ingredients of the Seresto flea and tick collar will kill these insects once they get into contact with the dog’s fur.


The Bayer Seresto flea and tick collars are non-greasy, non-toxic, hassle, and mess-free. However, some dogs are not used to wearing collars and might feel some irritation on the neck. These dogs might get some itchiness and redness, which usually go away in one to two weeks. Just make sure that the collar is not too tight. You can check this by fitting your two fingers in between the collar and your dog’s neck. Also, you might want to check with your vet for other reactions your dog might experience.


The Seresto dog flea collar has no scent. Therefore, you are sure that it is not irritating to the sensitive senses of your lovable pooch. This feature also makes it easy to put on your dog’s neck without any hassle. You can even use it alongside other collars and dog tags.

Some dog parents might think that the collar is not working since it doesn’t smell at all. But do not worry. Seresto flea collars work efficiently without the unpleasant chemical smells. Moreover, you don’t have to brush the collar against your dog’s coat, belly, or tail before putting it on. This innovative collar will do its work as soon as your pet wears it on its neck. The efficacy of the Seresto collar will work best within 24 to 48 hours upon application.

What are the side effects of the Seresto flea collar?

Although the Bayer Seresto collar is safe for use on dogs in general, some pooches might have an allergic reaction to the product and other chemicals. In some cases, temporary removal of the collar and bathing can lessen some adverse reactions. But, if your pet experiences any of the following symptoms, it is wise to consult with a veterinarian immediately:

  • Rashes
  • Vomiting
  • Diarrhea
  • Difficulty in walking
  • Tremors and seizures
  • Fatigue
  • Excessive drooling
  • Incessant scratching
  • Hair loss
  • Skin inflammation and lesions

Critical Feedback from Customers

There will always be two sides to the coin when it comes to products. Although the Seresto dog flea collar is generally useful and easy to apply for most users, unfortunately, some consumers did not have the same experience. Below are some unfavorable comments from customers in using this dog flea collar.

Itching and Irritation

Although very rare, the Seresto flea collar can cause severe itching on some dogs. It can result in your dog’s discomfort and irritability. You can reduce the uneasiness by taking out the collar and bathing your pet. However, be aware when your pup becomes too ill-tempered and delirious. You might want to bring your furball to the vet if this happens.

Effectiveness Not Lasting

Some consumers claimed that the efficacy of the collar only lasted for a few weeks, which is not the same as the eight-month effectivity as advertised. But, if used appropriately, the active ingredients of the collar will work from six to eight months. However, this may not be the case for dogs that bathe or swim a lot. Although the collar is water-resistant, the collar might not be as effective for the whole eight months for pups who frequently bathe or swim. It is more likely so for dogs that take a dip or wash more than once a month. The efficacy of the product can be possibly reduced in times like this.

seresto flea collar for dogs
Be sure to read the instruction manual that comes along with the product before using it on your dog.

Seresto Dog Collars – FAQ

For some pet parents, there might be specific issues in using the Seresto flea collar for the first time. Thus, listed here are some of the possible questions you might have.

Is Bayer Seresto safe?

The Seresto dog flea collars are safe for your pups. Bayer designed these flea collars according to the size and weight of dogs. You can get the Seresto large dogs’ collars for pooches that weigh more than 18 pounds and the Seresto small dogs’ collars for pups less than 18 pounds.

The large collars have a stronger dosage of active ingredients compared to the small sizes. So, you can be sure that your pets will get just the right amount of dosage and the best results.

Although some dogs might experience mild skin reactions to the collar, it is rare. It is also wise to read the instruction manual that comes with the collar for precautionary measures. Lastly, better consult with a veterinarian before using the collar on senior, pregnant, or breeding pups.

Is Seresto over-the-counter or prescription-only?

You don’t need any prescription to get the Seresto fleas and tick collar. It is safe and easy to use. However, you must read the instruction manual that comes along with the product before use. You might also want to consult with your veterinarian if you are unsure about its proper usage.

Is Seresto’s flea collar odorless?

Seresto flea collars do not have any scent. Unlike other flea collars that smell more like strong chemicals, the Seresto dog collars are gentle to your pets. It does not have any irritating smell that you will not have a hard time putting the collars on to your dogs. You can also be sure that this collar is safe to your pooch since it does not expel any harmful odor. Your fur baby can stay comfortable and relaxed while wearing the collar.

What are the best alternatives to Seresto collars?

There are other ways to fight against dog fleas and ticks. You can use topical solutions or chewable tablets. For chewable tablets, you can get Nexgard. These flea pills are ideal for dogs weighing 10 to 24 pounds. However, you need a prescription for this product.

Another alternative product against fleas and ticks that you can buy is Frontline Plus topical ointment. It is easy to apply, and you won’t need a prescription to purchase this product. Another option is the Bravecto Frulaner that comes in both topical solutions and chewable tablets.

The type of product to use will depend on your pet. Do not force something that your dog is not comfortable with, whether it be an ointment, a chewable tablet, or a flea collar.

Do Seresto collars repel ticks too?

The Seresto Flea Collar does not only work on fleas. It also kills ticks and lice that are already on your dog. The active ingredients will work within 24 to 48 hours. Moreover, Seresto dog flea collars destroy any re-infesting parasites within two to six hours. Fleas, ticks, and lice will be controlled and terminated as soon as they get into contact with the dog’s coat.

Taking care of your pooch entails time, energy, and commitment. Making sure that your pet is healthy and free from ticks, fleas, and lice must be one of your ultimate concerns. To prevent mite infestation, you can use the Seresto dog flea collar to ensure that your pup will always be active. It will also give you and your pup more quality and happy time together.

2 comments on “Seresto Dog Flea Collar – Review, Ingredients, Pros & Cons”

  1. James Uba

    Seresto collar is a safe and the best option for dogs and cats flea and ticks!

  2. Susie G Kauffman

    Is it safe if you want to breed your dog

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