NexGard for Dogs Review (2025): Does It Work and Is It Worth the Price?

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Your dog probably has fleas right now and doesn't know it

Fleas don't hibernate. They live year-round indoors, lay up to 50 eggs per day, and a single unprotected dog can seed an entire house in three weeks. Ticks are a slower problem — Lyme disease, Rocky Mountain spotted fever, ehrlichiosis — but the exposure adds up fast for dogs that spend any time outside.

NexGard (afoxolaner) is the monthly chewable that most US vets reach for first. Here's what it actually does, what the efficacy numbers mean, what the safety warning says, and where to buy it for roughly half of vet clinic pricing.

How NexGard works

Afoxolaner is an isoxazoline — a class of compounds that kill parasites by overstimulating their nervous systems. Once your dog chews the tablet, afoxolaner absorbs into the bloodstream. A flea or tick bites, ingests it, and dies. Simple mechanism, works well.

The bloodstream delivery is what makes oral preventatives more reliable than spot-ons. Nothing to wash off. Nothing that wears away with swimming or bathing. No transfer to kids or furniture.

The efficacy numbers

These come from FDA-submitted studies, not marketing copy:

• Fleas: 99.9% reduction within 24 hours — starts killing within 4 hours of the first dose
• Deer tick (Ixodes scapularis — the main Lyme carrier): 100% within 48 hours
• Lone star tick (Amblyomma americanum): 93.3% within 48 hours

Published in Parasites and Vectors among other journals. Worth knowing because "vet recommended" gets thrown around on a lot of products that don't have this kind of backing.

⚠️ The safety warning you need to know about

In 2018 the FDA issued an advisory covering the entire isoxazoline class — NexGard, Bravecto, Simparica, Credelio. The issue: neurologic adverse reactions in some animals, specifically muscle tremors, ataxia (loss of coordination), and seizures.

The required label language: "Use with caution in animals with a history of neurologic disorders such as epilepsy. Adverse reactions have been reported following use of this product."

For healthy dogs with no seizure history, the actual rate of these reactions is low — it's a documented risk, not a common one. For dogs with epilepsy or known neurological issues, the conversation belongs with your vet before any isoxazoline product.

NexGard vs the alternatives

vs Bravecto: Same isoxazoline class, different active ingredient (fluralaner). Bravecto lasts 12 weeks per dose — fewer tablets per year, less room for human error. Slightly cheaper per month when you run the math. If you regularly forget monthly medications, Bravecto is the better practical choice.

vs Simparica Trio: Adds heartworm prevention and deworming to the same monthly tablet. More expensive but genuinely convenient if your dog needs all three anyway.

vs Frontline Plus: Topical permethrin-based product. No prescription required in the US — it's classified as a pesticide, not a drug, because it sits on the skin rather than absorbing systemically. Lower efficacy than oral isoxazolines in head-to-head studies. Still the right call for dogs who can't tolerate the isoxazoline class.

vs Seresto collar: 8 months of protection, no monthly schedule. Imidacloprid and flumethrin — not an isoxazoline. Good for owners who want minimum systemic drug exposure.

Why NexGard costs less at Canada Pet Care than your vet charges

In the US, NexGard needs a veterinary prescription — the FDA classifies afoxolaner as a New Animal Drug. US vet clinics charge $20-25 per dose, or $120-150 for a 6-month supply, including the consultation that issued the prescription.

Canada Pet Care sources NexGard from licensed pharmacies in Australia and Europe, where it's sold over the counter. Same product — Boehringer Ingelheim manufactures for both markets. Different packaging, different price. A 6-pack runs $70-85 with free shipping over $49. Parallel importing for personal use is legal and widely practiced for both human and pet medications.

Frequently asked questions

Does NexGard kill ticks before they transmit Lyme disease?

Ticks typically need 36-48 hours attached to transmit Lyme. NexGard kills deer ticks within 48 hours, which substantially cuts transmission risk. It's not a perfect barrier — regular tick checks after outdoor time still matter.

Can puppies take NexGard?

Approved for puppies 8 weeks and older, minimum 4 pounds. Dosed by weight — Canada Pet Care stocks every weight class.

My dog vomited after taking it. What now?

If vomiting was within 2 hours of dosing, some may not have absorbed. Call your vet about whether to redose — usually they recommend a replacement if it was within the first hour.

Is it safe for pregnant dogs?

Not evaluated in pregnant, lactating, or breeding animals. Ask your vet before using in those situations.

Pros & Cons

Comparison Table

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