FRONTLINE Plus Flea & Tick Spot Treatment for Large Breed Dogs 45-88 lbs. (Purple) Count of 3
Frontline
Best for
Best topical
Amazon rating
Amazon aggregate, one input among many in the Verdict Score
Based on 1 trusted source
Current price
$32.78
Updated May 14, 2026 · 1 min read
Sources behind this verdict
8 reviewers weighted by source trust
The consensus
What reviewers found
Synthesized across the trust-weighted source mix below.
Frontline Plus is the longest-tenured product in this category, and the consensus across reviewers reflects that history — both good and bad. Verified-purchase reviewers at Costco, Walmart and Amazon praise ease of application and waterproof performance, and r/dogs threads contain plenty of long-time users who say it has worked reliably for years. The Costco listing (high-trust retailer) emphasizes coverage of adult fleas, flea eggs and larvae across the full life cycle.
What reviewers liked
- Carried by Costco (high-trust retailer), with verified-purchase reviewers praising long-term effectiveness
- Waterproof formula holds up after baths and swimming per manufacturer claims
- Targets the full flea life cycle — eggs, larvae and adults — not just adult fleas
- Long market history and broad availability across major retailers
Where it falls short
- Multiple r/dogs threads report it 'stopped working' due to apparent regional flea resistance
- r/PetAdvice user reported full reinfestation within a week despite correct application
- Does not repel mosquitoes the way Advantix does — only fleas, ticks and lice
- Application reviewers occasionally report greasy residue and a strong chemical odor
Frontline Plus is the longest-tenured product in this category, and the consensus across reviewers reflects that history — both good and bad. Verified-purchase reviewers at Costco, Walmart and Amazon praise ease of application and waterproof performance, and r/dogs threads contain plenty of long-time users who say it has worked reliably for years. The Costco listing (high-trust retailer) emphasizes coverage of adult fleas, flea eggs and larvae across the full life cycle.
The more important signal is the disagreement. Multiple r/dogs threads (high-trust community) report Frontline 'stopped working' after years of effective use, with users attributing the failure to regional flea resistance. An r/PetAdvice user reported a full reinfestation within a week of application. This is corroborated on r/cats and r/catcare for the feline variant. Reviewers don't frame this as a defective product — they frame it as a product whose efficacy is now geographically dependent.
For buyers in low-resistance regions, the trust-weighted consensus still supports Frontline Plus as a reasonable first-line topical. For buyers who have used it before without success, r/dogs commenters generally recommend rotating to K9 Advantix II or a prescription option rather than buying another box.
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- The #1 name in flea and tick protection
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- Trusted by pet owners for over 20 years**
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- Fast-acting, long-lasting flea and tick treatment thats waterproof 24 hours after application
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- Protects from fleas and ticks for a full month
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- Kills adult fleas, flea eggs, flea larvae, ticks, and chewing lice
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- Aids in the control of sarcoptic mange infestations
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- Stops existing flea infestations and prevents establishment of new infestations
I had my dogs on Frontline for years and never had any issues. Just make sure you're getting the updated formulas - Frontline Plus, Gold, and ...
I tried Frontline plus for the first time and it didn't work. I read somewhere that flea/tick shampoo can work against Frontline, rendering it ineffective.
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“Frontline Plus for Dogs” · YouTube
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