Seresto collar – the best flea and tick medicine

To protect your pets from blood-sucking parasites you can use various collars. Seresto produced by German manufacturers is the most popular one among cats and dogs owners.

Right in a few days after you start using this collar your pet will be protected from parasites attack and influence of those who are on its body.

When using the collar properly it stays efficient for 6-8 month.

Operation principle

Seresto is highly efficient against fleas, ticks, louse (it can be used both for cats and dogs). It combines insectoacaricide (against fleas and ticks) and repellent (deterrent) action.

The collar is sodden with a special substance that contains imidacloprid 1.25 g and flumethrin 0.56 g (for small and average sized dogs and cats) or 4,5 g and 2,03 g (for large dogs) correspondingly.

Active components constantly get to pet’s hair and are spread all around its body and hair without irritating the skin.

High efficiency is achieved due to combination of two antiparasitic components that amplify the effects of each other.

Active substances are: flumethrin – is an acaricide, that acts on adult specimen and their larvae. Imidacloprid is an acaricide, that effects almost all types of ectoparasites regardless of their stage of development.

The main feature is broad-spectrum and multipurposeness. All parasites existing on pet’s skin die. Besides, active components scare off fleas and lice, which prevents infection.

When using the collar properly the manufacturer guarantees that your pet will be protected from ticks for up to 8 month, from fleas and lice – for up to 6 month.

How does Seresto look like?

Seresto flea and tick collar is made of a special polymer in form of narrow stripe with manufacturer’s logo. For S/M size (for cats and small or medium sized dogs) the stripe length is 38 cm, for size L (for large dogs) – its length is 70 cm.

Anyway the collar has 2 or 3 loops to fix it on animal’s neck and 3 light-reflecting clinches that glow in the dark. When walking in the evening it allows watching your pet and not to lose sight of it.

Each collar is put in hermetically-sealed bag and than into a metal container with a corresponding marking.

What insects does the collar kill?


Flea is a year-round parasite. They live on animal’s body or in the place where the animal stays.

Fleas can be found outside, in cellars and porches of dwelling-houses or even in flats. It means they are everywhere where domestic animals and homeless dogs and cats as well as mice and rats can be.

Essential condition of fleas survival is food availability. They can bite an animal up 400 times a day.

To do this they wait for a cat or dog to pass by. You may also bring flea eggs home on your shoes or clothes.

Flea feeds with blood. They need “food” to make their colony grow. One flea female can lay about 50 eggs a day. Thus, each day flea colony has new species.

Flea females lay eggs into animal’s hair. Then eggs drop from the hair onto the place where the animal sleeps, on a sofa, floor, stairs etc.

Vermicular larvae appears in about several weeks after and they try to hide somewhere in some cracks, carpets and pets sleeping place.

Outside flea larvae dig themselves into the ground, leaves and grass. Some time later they turn into adult fleas and the cycle is repeated.

When you start fighting flea, it’s not enough to get rid of adult fleas that you see on your dog. This is just 5% from the whole population.

You can’t see the rest 95%. So, if you don’t get rid of these, you’ll continue seeing fleas on your pet.


These insects are dangerous not only for us, but for animals as well. Dogs are those who suffer the most from ticks bites, because cat owners (especially if its a high-bred one) very seldom let them go outside.

This is a zoophagous insect – a blood-sucking parasite from arthropods class, though it may feed with skin, dermal secreting and lymph.

This insect is a transmitter of various diseases. Not all types of ticks (there are about several thousands of them) are dangerous. Only few of them are really harmful.

Hungry ticks find their victim due to special thermal sensors they have. A dog passing by a bush or grass where a tick is becomes a target, then the tick jumps, holds onto the dog’s hair and stays there.

After this it starts looking for a place on dog’s skin with less hair on it (this is skin around ears, neck, legs, abdomen etc.).

Then the tick sucks in and starts sucking blood. It is almost impossible to tear it from the dog then and only when it is full it falls down from the dog itself.

Tick’s bite itself isn’t so dangerous for a dog, but infectious agents that its saliva may contain can cause lots of various dangerous and sometimes lethal diseases for a dog.

Instructions for use

The collar is available in three size – for puppies and small dogs, for large dogs, for cats. Length for dogs that weigh more than 8 kg is 70 cm, for pets that weigh less than 8 kg – it is 38 cm correspondingly.

The accessory is easy to use and it is considered to be safe for pets. The main thing is to follow the instructions for use. To make sure that this is an efficient protection measure for your pet, you should do the following:

  • Take the collar from its packaging and put it on your pet
  • The stripe shouldn’t be placed too tight. You should be able to put two fingers between the pet’s neck and the collar stripe
  • Fix the required length of the stripe and cut of the rest of it, since it may cause overdose of the substance.
  • The collar is a water-resistant one, but it may become less efficient when contacting with water or shampoos. That’s why when your pet is wearing the collar, you should minimize pet’s washing, especially with foams and shampoos.
  • When used properly the collar ensures protection for your pet for 8 month.
  • However, you shouldn’t take it off even for a short period of time, since risk that the pet gets infected in this case is significantly high.


Seresto passed lots of tests and studies, that proved its harmlessness. Despite this fact, in some cases you shouldn’t use it and choose another measure of protection.

You shouldn’t use this accessory in the following cases:

  • for puppies younger than 7-8 weeks
  • for pregnant female animals
  • for nursing dogs
  • if an animal is a high-sensitive one

In some cases it’s allowed to use even for pregnant and nursing female animals, but only after you consult a vet doctor.

Side effects

This collar very seldom causes any side effects. If during the first days of wearing the collar you notice that your pet has skin redness and itching, you shouldn’t worry.

These symptoms usually pass in 1.5-2 weeks. If they don’t or your pet’s state has become worse with itching or exfoliation, you must take your pet to a vet.

You should certainly take off the collar and thoroughly wash pet’s neck with soap and dry it. In some cases a vet doctor prescribes antihistamines to take.

Also you should consider using some other measure against parasites.

Usage precautions

Don’t forget that the item contains insecticides – poisons in other words. You should follow protective measures to prevent intoxication or other negative effects.

Take the collar only when wearing rubber (latex) gloves, especially if you have sensitive skin or you have some injuries on hands (sores, scratches) otherwise skin irritation is inevitable.

After you put the collar on a dog, wash you hands with soap. You mustn’t stroke a pet during first 5 hours after you put on the collar.

When using this accessory avoid pet’s contact with little kids.


This accessory has lots of advantages:

  • easy to use
  • it’s enough to put the collar once in the beginning of spring-and-summer season and you’ll forget about fleas and ticks for a long time
  • as a rule animals take it good and don’t try to take off
  • it is highly effective, protects a dog from lices, fleas, ticks and other ectoparasites. It not only helps the animal to get rid of them, but also prevents infection.
  • Long term of usage – one collar is enough for the whole season. At that you won’t need any additional measures.
  • It has no smell
  • Unlike similar products of other manufacturers it doesn’t have any odor that may bring discomfort to dog’s owners.
  • Fast results – it kills flea in 2 hours after wearing and ticks die in 6 hours (sometimes faster)
  • Safety. You can use it even for puppies at the age of 8 weeks and older. It seldom causes allergy or other side effects.
  • The collar tears under loads and excludes any possibility of choking

The most important points in a few words

  • Primary function – to fight with insects on animal’s body. The collar efficiently kills larvae and adult insects. It can be used both as preventative measure and for already infected dogs

  • Seresto collars are manufactured for small, large dogs and for cats

  • If the dog feels uncomfortable to move you can adjust the loops and make the collar not so tight. There should be a space (2 fingers wide) between the collar and dog’s neck

  • You should cut off the loose end of the collar. Thus, it won’t create excessive intoxication for the animal

  • Even despite the fact that you can moisten it, you shouldn’t do it on purpose. It’s better to take it off for a few minutes to wash the dog. Be careful if the collar has contact with shampoos, since its efficiency may sufficiently decrease

  • If the dog is very sensitive to insectoacaricide substances, it’s better to consult a professional vet whether you should use this collar. If no, the doctor will certainly tell you what alternative you have to fight against flea, ticks and other parasites

  • Pregnant and nursing dogs mustn’t wear the collar, since the substance may affect puppies and milk they get

  • The collar mustn’t be used for sick dogs, puppies younger than 7 weeks old, kittens younger than 7 weeks old

  • Don’t use Seresto collar together with other substances against parasites

About author: Sergey Schulz

Sergey is a founder and author of He’s been fond of aquarium husbandry since his early childhood. His favorite aquariums are biotopes (Amazon River), with Echinodorus and freshwater angelfish. However, through the years he’s had experience of keeping almost all types of freshwater fish and shrimps.