The Seresto Large Dog Flea & Tick Collar gives dogs and puppies 7 weeks of age and older weighing over 18 lbs. (8 kg) up to 8 months of continuous protection against fleas, flea larvae, ticks and chewing lice from a single collar. It starts killing fleas within 24 hours, kills and repels pests by contact, and is odorless and non-greasy. No prescription and no monthly doses to remember.
8 months
per collar
24 hrs
kills fleas
48 hrs
blocks new ticks
7 wks+
minimum age
About this item
8 months per collar
One collar gives 8 continuous months of flea and tick protection. Replace after 8 months for year-round prevention.
Kills & repels by contact
Fleas and ticks don’t have to bite your dog to be killed.
Fast-acting
Kills existing fleas within 24 hours, then new fleas within 2 hours. Prevents new tick infestations 48 hours after fitting.
Breaks the flea life cycle
Kills and repels fleas before they lay eggs, and kills flea larvae.
Treats chewing lice
Also labeled to treat and prevent biting (chewing) lice on dogs and puppies.
Water resistant
No need to remove for baths or swimming. Stays effective after shampooing, swimming, rain or sunlight.
Odorless & non-greasy
No liquid to apply, no residue on hands or furniture, no lingering smell.
Release mechanism
If your dog gets caught, its own strength is usually enough to widen the collar for a quick release.
No prescription needed
Genuine Seresto by Elanco, EPA Reg. No. 11556-155.
What Seresto protects your dog against
Repels and kills ticks for 8 months, including these species:
| Tick species | May transmit |
|---|---|
| Black-legged (deer) ticks | Lyme disease, anaplasmosis |
| American dog ticks | Rocky Mountain spotted fever, ehrlichiosis |
| Brown dog ticks | Ehrlichiosis, anaplasmosis, babesiosis, bartonellosis, canine hemoplasmosis, Rocky Mountain spotted fever |
| Lone Star ticks | Ehrlichiosis |
Protection against new ticks starts 48 hours after fitting; new ticks are then repelled or killed as quickly as 6 hours. Ticks already attached when you fit the collar may not die right away, so remove them at the time of application.
Fleas: kills fleas on your dog within 24 hours, then new fleas within 2 hours, for 8 months. Kills fleas before they lay eggs, kills flea larvae, and kills fleas that may transmit tapeworm infection (Dipylidium caninum), bartonellosis (Bartonella spp.) and rickettsiosis (Rickettsia felis), as well as fleas that can cause flea allergy dermatitis.
Tip: treat the home too
Flea pupae already in your home can keep hatching for 6 weeks or longer, depending on the climate. Treat your dog’s living areas with a product approved for home use while the collar works.
How Seresto works
Two active ingredients are held in Elanco’s patented polymer matrix and released slowly and continuously for the full 8 months. They spread from the point of contact over your dog’s skin and coat, so protection covers the whole body, not just the neck.
Imidacloprid 10.0%
Kills fleas and flea larvae.
Flumethrin 4.5%
Repels and kills ticks.
Working together
Repel and kill by contact. According to Elanco, no other product has this combination.
Seresto size chart
Dog collars are sized by weight, so weigh your dog before ordering. Never use a dog collar on a cat.
| Collar | For | Pet weight | Min. age | Length |
|---|---|---|---|---|
| Seresto Small Dog | Dogs & puppies | Up to 18 lbs. | 7 weeks | 15 in. |
| Seresto Large Dog (THIS ITEM) | Dogs & puppies | Over 18 lbs. | 7 weeks | 27.5 in. |
| Seresto Cat | Cats & kittens | Any | 10 weeks | See label |
How to apply
- Unroll
Remove one collar from its pouch right before use. Unroll it and make sure no plastic connector pieces are left inside. - Buckle & adjust
Feed the end through the buckle. Adjust so two fingers fit comfortably between the collar and the neck. - Trim
Pull the excess through the loop(s) and cut it to no more than 1 inch (2 cm) past the loop. Leave extra on a growing puppy. - Leave it on
Wear continuously for 8 months, checking the fit regularly on a growing puppy. Wash your hands with soap and cold water after fitting.
Good to know
Don’t attach a leash to the Seresto collar; it may break. Use a separate collar or harness for walks. If a collar is lost, a new one can be fitted right away.
Bathing & swimming
Water resistant
No need to remove the collar. Stays effective after shampooing, swimming, rain or sunlight.
Bathing
For the full 8 months, bathe no more than once a month, ideally before fitting, with a gentle pet shampoo.
Frequent swimmers
Dogs that swim once a month or more get 5 months of flea and 7 months of tick protection.
What to expect after fitting
Dogs new to collars may scratch at it for the first few days; make sure it isn’t too tight. Slight hair loss or mild skin reactions where the collar sits may occur and usually clear within 1 to 2 weeks without removing the collar.
When to call your vet
Individual sensitivities are rare but possible with any pet pesticide. If your dog shows a skin reaction at the collar site, lethargy, loss of appetite, vomiting or unusual behavior, remove the collar and contact your veterinarian. Reactions can be reported to Elanco at 1-800-255-6826.
What’s in the box
One Seresto Large Dog collar, sealed in a protective pouch, in the Seresto tin. Protecting two dogs? Save with the Seresto Large Dog 2-Pack.
Specifications
| Brand | Seresto by Elanco |
|---|---|
| Pack size | 1 collar |
| For | Dogs & puppies |
| Pet weight | Over 18 lbs. (8 kg) |
| Collar length | 27.5 in. |
| Minimum age | 7 weeks |
| Protection | 8 months per collar |
| Protects against | Fleas, flea larvae, ticks, chewing lice |
| Active ingredients | Imidacloprid 10.0%, flumethrin 4.5% |
| Features | Odorless, non-greasy, release mechanism, water resistant |
| Prescription | Not required |
| EPA Reg. No. | 11556-155 |
| Manufactured for | Elanco US Inc., Indianapolis, IN |
| Country of origin | Germany |
| UPC | 724089579607 |
Genuine Seresto: what to look for
- EPA Reg. No. 11556-155 and “Manufactured for Elanco US Inc” on the label
- An odorless, non-greasy collar
- Sealed in a protective pouch inside the Seresto tin
Questions about a collar? Call Elanco at 1-800-255-6826. Storage: the EPA does not require an expiration date on Seresto. Keep it sealed in the original packaging in a cool, dry place out of reach of children. Dispose of the pouch and used collar in the trash; the tin may be recycled.
Frequently asked questions
How long does a Seresto collar last?
How fast does Seresto work?
Which Seresto is right for my dog?
Can my dog swim or be bathed with it on?
How tight should it be?
Does Seresto need a prescription?
Does Seresto expire?
What if my dog gets caught on something?
Can I attach a leash to it?
How do I know it’s genuine?
Precautions
- Read the entire label before use. Do not let children play with this collar; it contains small parts.
- For external use on dogs only. Do not use on puppies under 7 weeks.
- Consult your veterinarian before use on debilitated, aged, breeding, pregnant or nursing animals, or pets on medication.
- Avoid contact with eyes, skin or clothing.
