Quick answer: The Seresto Large Dog collar is a good fit for many hunting dogs. One collar gives up to 8 months of flea and tick protection for dogs over 18 lbs and at least 7 weeks old. It uses 10% imidacloprid and 4.5% flumethrin, and it kills and repels ticks on contact. The tradeoffs: frequent swimming shortens its life, it doesn’t prevent heartworm, and you need to fit it carefully on dogs that run heavy cover.
Check the current price of the Seresto Large Dog collar
Seresto Large Dog collar: the specs
| For | Dogs and puppies 7 weeks and older, over 18 lbs |
|---|---|
| Protection | Up to 8 months against fleas, ticks and lice |
| Active ingredients | Imidacloprid 10.0%, flumethrin 4.5% |
| How fast it works | Starts killing fleas within 24 hours and ticks within 48 hours. After that, newly arriving ticks are repelled or killed within about 6 hours. |
| Water | Stays effective after rain and occasional swimming or shampoo. Swimming or bathing more than once a month shortens protection (about 5 months for fleas, 7 months for ticks). |
| Does NOT cover | Heartworm or intestinal worms |
Label details are from the Seresto Large Dog product information.
Why hunting dog owners like it
- One and done for the season. Put it on in late summer and it covers bird season and deer camp without monthly doses to forget.
- Repels as well as kills. Flumethrin works on contact, so many ticks are repelled or die before they settle in to feed. That matters because blacklegged ticks generally need 24 to 48 hours of feeding to pass Lyme disease.
- Nothing to pill. Handy for dogs that spit out tablets or have sensitive stomachs.
- Covers the whole kennel easily. One collar per dog, one date to remember.
Where it falls short for working dogs
- Heavy water work. A retriever swimming several times a week through duck season will likely need a new collar sooner than 8 months. For dogs that live in the water, ask your vet whether an oral product makes more sense.
- Heartworm. You still need a separate heartworm preventive.
- Snag risk. Any collar can catch on brush, fences or crate doors. Seresto has a built-in release mechanism, but run it on a properly fitted collar and don’t leave extra length hanging.
- Two collars on one neck. Most hunters also run a GPS or e-collar. Fit the Seresto so it lies flat and doesn’t sit under the e-collar contact points.
What did the EPA find about Seresto collars?
After reports of pet illnesses and deaths, the EPA reviewed Seresto. The agency did not cancel the collar and found it still meets federal safety standards. Of the deaths it reviewed, only those caused by mechanical strangulation or trauma from the collar were judged “probably” or “definitely” related to the product. The EPA required added label warnings, owner and vet outreach, better incident reporting, and a safety review of the collar’s release mechanism. Its advice to owners is to watch your pet after putting on a new collar, especially the first time, and remove it and call your vet if you see a reaction. Read the EPA’s Seresto collar review.
How to fit a Seresto collar on a hunting dog
- Take it out of the package, pull off the small plastic connectors, and unroll it.
- Slide the end through the buckle and adjust until you can fit two fingers between the collar and the neck.
- Pull the end through the loops and trim the extra, leaving about 1 inch. Leave more on a growing pup and re-check the fit every couple of weeks.
- Check the skin under the collar during your post-hunt tick check. Redness, hair loss or sores mean remove it and call your vet.
- Write the date on the prevention card in your truck field kit.
Buying tip: avoid counterfeits
Fake Seresto collars have been sold online. Buy from a trusted retailer or your vet, and be wary of prices that look too good to be true or packaging that looks off.
Seresto vs. other options for hunting dogs
| Option | Best for | Watch out for |
|---|---|---|
| Seresto collar | Upland dogs, hounds, dogs that are hard to pill | Shorter life with frequent swimming. No heartworm protection. |
| Monthly topical (spot-on) | Budget-minded owners, multi-dog kennels | Bathing and swimming timing. Monthly reminders. |
| Oral chewable (prescription) | Heavy water work. Some combine heartworm protection. | Needs a vet visit. The FDA notes rare neurologic reactions in the isoxazoline class. |
Budget topical option: our Amazon Basics flea and tick review. More on prescription chews: the FDA fact sheet on isoxazoline products.
Our verdict
For an upland dog or hound in tick country, the Seresto Large Dog collar is one of the easiest ways to stay protected through the whole season. It saves you from remembering monthly doses and repels ticks before they feed. Duck dogs that swim constantly may do better on an oral product, and every dog still needs heartworm prevention and a post-hunt tick check.
See the Seresto Large Dog collar on Amazon
Frequently asked questions
Is the Seresto collar safe for hunting dogs?
The EPA reviewed Seresto and kept it registered, finding it meets federal safety standards. Fit it properly, watch your dog after putting it on, and remove it and call your vet if you see a reaction.
Can my Lab swim with a Seresto collar on?
Yes. But swimming or bathing more than once a month shortens protection to about 5 months for fleas and 7 months for ticks, according to the label.
Does Seresto protect against Lyme disease?
It kills and repels ticks, including blacklegged ticks, which lowers the chance of ticks feeding long enough to pass Lyme disease. Keep doing tick checks and ask your vet about the Lyme vaccine.
How old does a puppy have to be for Seresto?
At least 7 weeks. Use the small-dog collar until the pup is over 18 lbs.
Sources
- Seresto Large Dog product label information
- U.S. EPA: Seresto pet collar review
- Companion Animal Parasite Council: Lyme disease
Last reviewed September 30, 2026. General information, not veterinary advice. Always read and follow the product label.
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