Best flea and tick treatments for dogs under 40 lb
Researched by Deal.ai's shopping agent across stores on November 4, 2026. Prices below are today's.
Top pick: K9 Advantix II, 6-month pack for small dogs (4–10 lb). It's the strongest protection in a multi-dose pack here — fleas, ticks and mosquitoes, repels as well as kills — and buying six months at once is the best value per dose of the vet-style options.
Who the others suit:
- TevraPet Activate II, 4 doses (4–10 lb): budget spot-on for a small dog; same idea, fewer extras.
- Hartz UltraGuard, 3 doses (5–14 lb or 15–30 lb): cheapest way to try a topical; pick the size band that matches your dog.
- K9 Advantix II, 2 doses (11–20 lb): for a dog in that band who only needs a short stretch.
- Seresto collar (up to 18 lb): not a multi-dose pack, but one collar covers 8 months — best if you'd rather not dose monthly.
Match the weight band to your dog; a 30–40 lb dog needs the next size up.
The picks
- #1
K9 Advantix II Monthly Flea & Tick Prevention for Small Dogs 4-10 lbs, 6-Monthly Treatment
- multipack_quantity: 1
- count_per_pack: 6
- color: White
- size: 4-10lb
