NexGard vs Simparica Trio: Which All-in-One Protection Is Better?

Choosing between NexGard and Simparica Trio is one of the most common decisions dog owners face when shopping for all-in-one flea, tick, and heartworm protection. Both are chewable tablets, both are trusted by vets worldwide — but they differ in some important ways. Let's break down exactly what each product covers so you can pick the right fit for your dog.

What Each Product Actually Covers

The biggest distinction in the NexGard vs Simparica Trio comparison comes down to breadth of coverage. Understanding what parasites each product targets helps you decide whether you need additional treatments or can rely on a single tablet.

NexGard (original) is a monthly chewable that kills fleas and ticks. It does an excellent job at both, but it does not include heartworm or intestinal worm protection. If you choose NexGard, you'll typically need a separate heartworm preventative and a worming schedule alongside it.

NexGard Spectra expands on the original by adding heartworm prevention plus treatment for intestinal worms (roundworms, hookworms, and whipworms). You can explore the full NexGard range here to see which variant suits your dog's weight class.

Simparica Trio delivers flea, tick, heartworm, and intestinal worm protection in a single monthly chew — making it a genuine all-in-one solution. Browse the complete Simparica Trio collection to find the correct size for your dog.

Key Differences Between NexGard and Simparica Trio

Both brands use isoxazoline-class active ingredients to target fleas and ticks, but the specific compounds differ. NexGard products use afoxolaner, while Simparica Trio uses sarolaner combined with moxidectin and pyrantel for broader parasite coverage.

Here's a quick comparison of the key features:

• Parasites killed: NexGard original covers fleas and ticks only; NexGard Spectra adds heartworm and intestinal worms; Simparica Trio covers fleas, ticks, heartworm, roundworms, and hookworms in one tablet.
• Administration: All three are flavoured monthly chewables designed for easy dosing.
• Minimum age: NexGard is labelled for puppies from 8 weeks; Simparica Trio is labelled for puppies from 8 weeks as well.
• Minimum weight: NexGard starts at 2 kg; Simparica Trio starts at 1.25 kg.

The lower minimum weight for Simparica Trio can be a deciding factor for owners of very small or toy-breed puppies.

Speed of Action and Lasting Effectiveness

When you're comparing NexGard vs Simparica for speed, both act impressively fast. NexGard begins killing fleas within 6–8 hours and ticks within 24–48 hours. Simparica Trio starts killing fleas within 3 hours and ticks within 8 hours of administration.

That faster onset can matter in heavy flea or tick environments. If rapid knockdown is your priority, Simparica Trio has a measurable edge on the clock.

Both products maintain protection for a full 30 days, so monthly dosing keeps your dog covered year-round. Consistent, on-schedule dosing is far more important than the brand you choose — gaps in treatment are when parasites gain a foothold.

For a broader look at every option available — spot-ons, chewables, and combination treatments — visit our flea, tick, and worm category and filter by your dog's weight.

How to Choose the Right Option for Your Dog

If simplicity matters most, a true all-in-one covering fleas, ticks, and heartworm prevention in a single chew is hard to beat. Simparica Trio and NexGard Spectra both fit that brief, reducing the number of products — and the chance of missed doses.

If your dog is already on a separate heartworm preventative that you're happy with, the original NexGard chew may be all you need for flea and tick control. There's no point doubling up on heartworm ingredients unnecessarily.

Consider your dog's size, age, and temperament around taking tablets. Both brands are palatable and chewable, but some dogs strongly prefer one flavour over the other. A quick trial of a single month's dose can tell you a lot about acceptance.

Finally, think about your budget over a 12-month cycle. Buying a multi-pack or subscribing for regular deliveries often brings the per-dose cost down significantly — check the product pages for bundle pricing.

Frequently Asked Questions

Can I switch my dog from NexGard to Simparica Trio mid-year?

Yes. Simply start the new product on the date the next NexGard dose would have been due. There is no need for a washout period between isoxazoline-based chewables, and your dog's protection continues uninterrupted.

Do these chewables also protect against tapeworms?

Neither NexGard Spectra nor Simparica Trio covers tapeworms. If tapeworm is a concern — for example, if your dog occasionally ingests fleas or hunts — you may need a dedicated tapeworm treatment in addition to your monthly chew.

Are these products safe for breeding or pregnant dogs?

The safety data for use in breeding, pregnant, or lactating dogs varies between products and is not fully established for all scenarios. Have a quick chat with your vet if your dog falls into any of these categories to confirm the best approach.

Ready to protect your dog with a single monthly chew? Browse our full range of flea, tick, and worm prevention products and find the right match for your dog's weight and lifestyle.