Best Flea & Tick Prevention

Pros

• DailyMed / NADA 141-521: prevents heartworm disease; treats/controls roundworms and hookworms; kills adult fleas; labeled for six tick species including lone star and Asian longhorned; prevents Borrelia burgdorferi by killing Ixodes scapularis.
• Zoetis pet-owner page and 2025 label: prevents Dipylidium caninum (flea tapeworm) as a direct result of killing vector fleas; can be given with or without food.
• Dogs and puppies 8 weeks and older, from 2.8 lb — among the lowest weight floors on this list.

Cons

• Contains sarolaner (isoxazoline). FDA fact sheet and the Trio label warn of neurologic adverse reactions including seizures, including in dogs without a prior history. Use with caution if there is a seizure/neurologic history.
• Prescription only. Not a cat product. Does not replace environmental flea control for untreated pets in the house.
• We did not independently time ‘starts killing fleas within 4 hours’; that figure is from Zoetis/label studies, not our stopwatch.

Score breakdown

Specs

Actives

sarolaner, moxidectin, pyrantel pamoate

Agency

FDA NADA 141-521

Species

Dogs only (8 weeks+, 2.8 lb+)

Interval

Once monthly

Rx

Yes

Score Notes

quality 9 = 3 fleas + 2 ≥4 named ticks + 1 Lyme + 2 HW/nematodes + 1 flea-tapeworm indication. safety 6 = 8 FDA −2 isoxazoline fact sheet. value 5 = 3 base + 2 combo. ease 8 = oral chew, with or without food.

Pros

• Official Elanco US page: 8 continuous months; kills and repels fleas and ticks through contact (no bite required); water-resistant with labeled caveats if the dog swims often.
• EPA registration continued after a multi-year review announced with FDA support in 2023 (Elanco investor release). Dog and cat collars, small-dog vs large-dog SKUs.
• No veterinary prescription. One application vs monthly topicals or chews.

Cons

• Safety is scored down because EPA’s 2023 review existed precisely because of incident reports (Elanco says most frequent were dermatologic at the collar site). Registration continued; that is not the same as ‘no incidents.’
• Elanco publishes a counterfeit-collar warning: buy from authorized retailers, verify lot numbers. Fake collars are a real documented problem.
• If a dog swims once a month or more, Elanco’s own footnote shortens flea control to 5 months and tick control to 7 months. Not a heartworm product.

Score breakdown

Specs

Actives

imidacloprid + flumethrin (EPA collar)

Agency

EPA (e.g. 11556-155 dog collars per EPA label PDF)

Species

Dogs (7 weeks+) and cats (official cat SKU)

Interval

Up to 8 months (shorter if frequent swimming — dog label footnote)

Rx

No (OTC)

Score Notes

quality 8 = 3 fleas + 2 ticks + 1 lice/larvae icons on official pack + 2 eight-month duration. safety 5 = 7 EPA −2 incident-review product. value 8 = 3 base + 3 OTC + 2 duration. ease 7 = set-and-forget minus official counterfeit friction.

Pros

• DailyMed / NADA 141-426: 12 weeks against fleas and black-legged, American dog, brown dog, and Asian longhorned ticks in dogs 6 months+ weighing 4.4 lb+.
• Fewer doses than monthly chews (about four per year if you stay on the 12-week interval).
• Same brand family includes topical and cat products on bravecto.com — this ranking row is the 12-week dog chew only.

Cons

• Isoxazoline (fluralaner): same FDA neurologic class warning. Label also notes adverse events after use in breeding females.
• Lone star ticks (Amblyomma americanum) are labeled for 8 weeks, not 12 — redose earlier if that tick is a risk.
• Must be given with food (reduced bioavailability if fasted). Not a heartworm preventive. 12-week chew is not labeled for puppies under 6 months (use Bravecto 1-Month for younger puppies — not scored here).

Score breakdown

Specs

Actives

fluralaner

Agency

FDA NADA 141-426

Species

Dogs 6 months+, 4.4 lb+

Interval

Every 12 weeks (every 8 weeks if lone star tick exposure)

Rx

Yes

Score Notes

quality 7 = 3 fleas + 2 named ticks + 2 twelve-week duration. safety 6 = 8−2 isoxazoline. value 5 = 3 base + 2 duration. ease 8 = oral, fewer refills, food required.

Pros

• frontline.com FAQ still describes Gold for dogs and cats: triple-action (fipronil, (S)-methoprene, pyriproxyfen), kills fleas/eggs/larvae and ticks through day 30, chewing lice.
• EPA-style registration on marketed cartons (Drugs.com label transcription: 2596-178-65331 dogs; 2596-179-65331 cats). No prescription.
• Not an isoxazoline — so it does not carry the FDA class seizure fact sheet that applies to NexGard, Bravecto, and Simparica Trio.

Cons

• We did not treat Lyme prevention as a labeled indication comparable to NexGard/Trio; Gold marketing says it kills ticks that may transmit Lyme, which is not the same as an FDA Borrelia claim.
• Official Gold FAQ: pet should stay dry 24 hours after application. Topical residue/odor vs a chew.
• frontline.com homepage currently also pushes Plus and Shield; Gold remains on the FAQ and Gold product URLs. Not a heartworm product. Use only the species and weight SKU on the box — dog formulas are not cat formulas.

Score breakdown

Specs

Actives

fipronil, (S)-methoprene, pyriproxyfen

Agency

EPA (carton/Drugs.com: 2596-178-65331 dogs; 2596-179-65331 cats)

Species

Dogs (8 weeks+, 5 lb+ per Gold FAQ) and cats (separate SKU)

Interval

Once monthly (30 days)

Rx

No (OTC)

Score Notes

quality 6 = 3 fleas + 1 ticks (species not enumerated like Rx labels) + 1 IGR + 1 lice. safety 7 = EPA start, no isoxazoline penalty. value 6 = 3 base + 3 OTC. ease 6 = monthly topical, stay-dry window.

Pros

• DailyMed / NADA 141-406: beef-flavored monthly chew; fleas plus black-legged, American dog, lone star, brown dog, and longhorned ticks; Lyme prevention as a result of killing Ixodes scapularis.
• Dogs and puppies 8 weeks+, 4 lb+; can be given with or without food (manufacturer dosing text).
• Same company sells NexGard PLUS (adds heartworm/worms) — not scored here because this row is the classic flea/tick chew.

Cons

• Isoxazoline (afoxolaner): FDA neurologic class warning; NexGard label: use with caution in dogs with a history of seizures or neurologic disorders.
• Does not prevent heartworm. Households that want one chew for HW + fleas/ticks should discuss Simparica Trio or NexGard PLUS with a veterinarian (PLUS not ranked this pass).
• Dogs only. Safe use in pregnant/breeding/lactating dogs has not been evaluated per the label.

Score breakdown

Specs

Actives

afoxolaner

Agency

FDA NADA 141-406

Species

Dogs 8 weeks+, 4 lb+

Interval

Once monthly

Rx

Yes

Score Notes

quality 6 = 3 fleas + 2 named ticks + 1 Lyme. safety 6 = 8−2 isoxazoline. value 3 = base only (Rx, monthly, not a HW combo). ease 8 = oral chew, with or without food.