10 Best Flea Treatments For Dogs 2026 in the United States

The Seresto Small Dog Flea & Tick Collar is a solid choice for pet owners looking for long-lasting, easy-to-use protection for dogs under 18 pounds. It uses two active ingredients, imidacloprid and flumethrin, to kill and repel fleas and ticks effectively, starting within 24 hours. This collar works by contact, so fleas don’t need to bite your dog to be eliminated, which can reduce irritation and risk of disease. Suitable for puppies as young as 7 weeks, it fits small breeds comfortably and lasts up to 8 months, which is longer than most monthly treatments. The collar is unscented and non-greasy, making it hassle-free to apply and wear.

One possible downside is that collars might not be ideal if your dog frequently swims or gets wet, as it may affect effectiveness. Also, while side effects are rare, some dogs could be sensitive to the ingredients, so monitoring your pet when first using it is recommended. This collar offers a convenient, vet-recommended option for continuous flea and tick prevention without the need for monthly dosing, especially suitable for owners who prefer a low-maintenance solution for small dogs.

PetArmor Plus for Dogs is a topical flea and tick treatment designed specifically for small dogs weighing between 5 and 22 pounds, suitable for puppies 8 weeks and older. It contains the active ingredients fipronil and (S)-methoprene, which are commonly used in trusted flea treatments and work by killing adult fleas, eggs, larvae, ticks, and chewing lice. This product stands out because it breaks the flea life cycle, helping prevent re-infestation rather than just temporarily repelling pests.

The treatment is waterproof and starts killing fleas within 24 hours, providing protection for a full 30 days per application. It comes in a pack of six doses, offering six months of continuous protection if used monthly. Application is straightforward, with drops applied to the skin between the dog's shoulder blades; however, some owners may notice greasy fur for up to 48 hours, which can be cleaned off with a damp cloth. The no scent and allergen-free formula makes it suitable for sensitive pets.

Users should keep treated dogs away from other pets and children for about a day while the product dries. Although monthly applications might be seen as a bit frequent compared to longer-lasting options, this product remains a reliable, vet-quality choice for small dog owners looking for an effective, easy-to-use flea and tick solution.

FRONTLINE Plus for Small Dogs is a topical flea and tick treatment designed for dogs weighing between 5 and 22 pounds, effective for a full month per application. Its active ingredients, fipronil and (S)-methoprene, work together to kill adult fleas, flea eggs, larvae, chewing lice, and ticks, helping to stop flea infestations before they start. This product is waterproof and fast-acting, which means it remains effective even if your dog gets wet. It’s suitable for puppies aged 8 weeks and older, making it a good choice for small dogs from a young age.

Applying the treatment is simple—just part your dog’s hair between the shoulder blades and squeeze the liquid onto the skin—though you need to be careful to avoid applying it to the hair coat or letting your dog lick the area until it’s dry. Many pet owners trust FRONTLINE Plus due to its long-standing reputation and consistent results. However, it should not be used on dogs under 5 pounds or younger than 8 weeks. Side effects are rare, but as with any medication, mild skin irritation might occur. The package includes six applicators, making it cost-effective for ongoing monthly use.

If you have multiple pets, remember to treat all dogs or cats monthly to better control infestations. While it doesn’t have a scent, some dogs might still be sensitive to the topical feel. This product offers an easy-to-use and reliable solution for small dog owners wanting to protect their pets from fleas and ticks over a full month, provided the weight and age guidelines are followed.