Seresto Flea & Tick Collar for Large Dogs Over 18 lbs
The collar for dogs heavier than 18 lbs. It kills and repels fleas and ticks by contact, so a pest does not have to bite to die, starts within 24 hours and keeps going for 8 continuous months — no greasy drops, no monthly reminder.
$49.99
Key features
- For dogs and puppies over 18 lbs
- 8 continuous months per collar
- Works by contact — no bite needed
- Starts within 24 hours
- Non-greasy, unscented, no prescription
- Delivered by the store you order from
- Returns through your order
- No prescription needed
What is inside
| Active ingredients | Imidacloprid, Flumethrin |
|---|---|
| Protection | 8 continuous months |
| Starts working | Within 24 hours |
| Form | Non-greasy collar, unscented |
| Dog size | Over 18 lbs |
| Weight | 3.84 oz per collar |
| Packs | 1 or 2 collars |
Good to know
Two dogs, or one dog for 16 months? The 2-collar pack covers both.
Large Dog Collar
How the Seresto collar works on large dogs
A Seresto collar releases its two active ingredients, imidacloprid and flumethrin, slowly from the collar into the coat. Fleas and ticks are killed and repelled on contact, which means they do not need to bite your dog first. Once the collar is on, protection starts within 24 hours and continues for 8 months, so one collar covers most of a flea and tick season. It kills fleas and ticks across the whole dog, from the neck to the tail, as long-lasting flea and tick prevention for dogs and puppies 7 weeks old and older.
Large Dog Collar
Fitting the Seresto collar on a big dog
Put the collar around the neck, push the end through the buckle and adjust the fit as the label describes; then trim the extra length. Write the date down — the collar gives tick protection and flea control for 8 months, and then it is time for a new one.
Large Dog Collar
Vet-recommended without a vet visit
Seresto is described by its maker, Elanco Animal Health, as the #1 veterinarian-recommended flea and tick collar. It needs no prescription, leaves nothing greasy on the fur and has no scent.
What owners say
This really helped with the fleas!!
Now this worked! After trying natural plant based collars to get rid of fleas and larvae to no avail. I had to go to this. I am not a fan of medicated collars, but we had to use something a bit stronger. So after using Wondercide shampoo, I put these on my pups. They worked. I didn't notice anymore scratching, and both dogs seemed much happier. I din't notice any alarming side effects or lethargy. No scent was nice too
AGSeptember 28, 2026 · Large Dog Collar
Quick answers
How long does it last?
One Seresto collar works for 8 continuous months and starts within 24 hours.
Which size do I need?
Dogs over 18 lbs: large dog collar. Dogs under 18 lbs: small dog collar. Cats and kittens: the cat collar.
Is a prescription needed?
No. Seresto is sold without a prescription.
