Bravecto vs NexGard vs Simparica vs Seresto: An Australian Comparison

This page is for choosing prevention, not for treating a dog that is already sick. If your dog is wobbly in the back legs, has a changed bark, is retching or breathing oddly, go to a vet now — and read the paralysis tick guide on the way, not this one. No preventative reverses tick paralysis once it has started.

Almost every “best flea and tick treatment” comparison you will find was written for American dogs. It is not that the advice is slightly off — it is that the single most dangerous parasite your dog faces does not exist where those articles were written. Ixodes holocyclus, the Australian paralysis tick, lives on the east coast of this country and nowhere else on earth.

That changes the whole question. A product can be excellent against fleas and brown dog ticks and still be the wrong choice here. (If fleas are the actual problem, our page on fleas on dogs in Australia goes through what these labels claim about them, and what they claim about the house.) And — this is the part that catches people — the protection period printed on the front of the box is frequently not the paralysis tick period.

This page compares what is actually registered with the APVMA for use in Australia, using the manufacturers’ own approved claims.

A note on money, because this is a buying guide: this page contains no affiliate links and earns nothing at the time of writing. If that ever changes, it will say so in plain words at the top of the page, before the recommendations, not in small print at the bottom.

The three things that actually decide this

1. Whether it is registered for paralysis tick at all, and for how long. Not all tick claims are the same claim. Bravecto Spot-On covers paralysis tick for six months and brown dog tick for twelve weeks — from the same tube.
2. Whether you will actually give it on time. This matters more than any difference between the products. A monthly chew you forget in November is worse than a collar you fit once.
3. Whether there is a cat in the house. One of these products kills cats. It is otherwise a perfectly reasonable option, which is exactly why it catches people out.

What is actually in them

Four of the five leading options are the same class of drug wearing different labels. NexGard (afoxolaner), Bravecto (fluralaner), Simparica (sarolaner) and Credelio (lotilaner) are all isoxazolines. They are given by mouth or absorbed into the bloodstream, and they work when the parasite feeds.

Seresto is the outlier. It is a collar containing imidacloprid and flumethrin, which spread through the oily layer of the skin and coat and work on contact — the tick does not have to bite to be affected.

That distinction matters more than the brand names, and we will come back to it.

The comparison

All durations below are the registered Australian claims, taken from the manufacturers’ Australian product information and APVMA-approved labels.

NexGard Spectra, Simparica Trio and Credelio Plus also cover heartworm and intestinal worms, which is the practical argument for a monthly all-in-one: one product, one date, most things handled.

Each of those three also comes in a plain version — NexGard, Simparica and Credelio — that does fleas and ticks without the heartworm and worm cover. There is a Bravecto 1-Month Chew for small dogs as well. They are left out of the table to keep it readable, not because they are inferior; if your dog is already on a separate heartworm product, the plain versions are the ones to ask about.

The three places people get caught

1. The headline number is often not the paralysis tick number

Read the table again and look at the gaps.

• Bravecto Spot-On: six months for paralysis tick, twelve weeks for brown dog tick.
• Seresto: eight months for paralysis tick and fleas, four months for brown dog and bush ticks.
• Bravecto Chew: three months for paralysis tick, but the label directs dosing every two months for brown dog and bush ticks.
• Bravecto Quantum: twelve months for paralysis tick, eleven for brown dog tick.

If you are in Queensland or northern New South Wales, where brown dog ticks are a genuine year-round nuisance, a “six month” product may be giving you three months of cover against the tick in your yard. Neither number is wrong. They are simply different claims, and only one of them is on the front of the box.

2. Bravecto Chew: three months, not four

You will still find Australian articles, and some retailers, quoting four months of paralysis tick protection from the Bravecto chew. The manufacturer’s current Australian instruction is plainer: treat every three months for flea and paralysis tick protection.

The label directs dosing every three months. If a four-month belief is sitting in your calendar, that is four weeks of a Queensland spring with nothing on board.

3. Most of these require the tick to bite

Every isoxazoline — NexGard, Bravecto, Simparica, Credelio — kills the tick after it attaches and begins feeding. NexGard Spectra’s own product information states that ticks are killed within 48 hours; Bravecto Spot-On controls paralysis ticks within 48 hours of application.

The registered efficacy figures sit above 95%, which is why a 48-hour kill works in practice — but above 95% is not 100%, and it is not the same as the tick never attaching. You will still find ticks on a well-protected dog. Finding one does not mean the product failed.

Seresto and Advantix are the exceptions — both repel as well as kill, so the parasite does not need to bite. That is a genuine point in the collar’s favour, and it is rarely the reason people choose it.

Either way, none of this replaces searching your dog every day. The Bravecto Quantum label puts it about as bluntly as a manufacturer ever will: “The risk of tick paralysis cannot be entirely eliminated.” There is a proper method for searching in the paralysis tick guide, and it takes two minutes.

Safety: the isoxazoline question

This comes up constantly in dog groups, usually in a form somewhere between “these are poison” and “there is nothing to it”. Neither is right.

In 2018 the US Food and Drug Administration issued a formal alert about the isoxazoline class — the drugs in Bravecto, NexGard, Simparica and Credelio. It said that some animals given them “have experienced adverse events such as muscle tremors, ataxia, and seizures”, and that these were seen consistently across the class. Manufacturers were asked to update their labelling. NexGard Spectra’s Australian product information lists seizures among rare adverse reactions.

The same alert is equally clear that the products “continue to be safe and effective for the majority of animals” and they remain approved on both sides of the Pacific.

What that means practically:

• If your dog has a history of seizures or any neurological condition, raise it with your vet before starting an isoxazoline. This is the single situation where the choice genuinely matters, and Seresto — a different class of drug entirely — is the obvious thing to discuss.
• For a dog with no such history, the risk is small and the risk of tick paralysis in eastern Australia is not. Untreated tick paralysis kills dogs; that is the comparison that matters.
• Report anything unusual after dosing to your vet. Adverse event reporting is how the label got updated in the first place.

What we are not going to tell you is that a natural alternative fills this gap. It does not, and the evidence on natural tick prevention is covered honestly elsewhere on this site.

If you have a cat

Advantix contains permethrin and is dangerous to cats. Elanco’s own Australian guidance describes it as “very dangerous to cats because of their unique physiology”, and says a cat should be kept away from a treated dog for up to 48 hours.

In a household where a cat sleeps against the dog, grooms the dog, or shares bedding, that separation is not realistic. Choose something else. This is not a small-print caution — permethrin poisoning in cats is a genuine emergency.

Advantix also needs reapplying every two weeks for paralysis tick control rather than monthly, which makes it hard work even in a cat-free house.

What it costs

Less than people expect, and closer together than people expect.

At Australian online retail in September 2026, a six-pack of NexGard Spectra for a mid-sized dog runs roughly $100 to $110 — about $17 to $19 a month. Bravecto packs sit in a similar per-month band and cover a longer period per dose. Prices move constantly, vary by your dog’s weight bracket, and are usually lower online than over the counter, so treat those figures as a starting point and check before you buy.

The more useful way to think about it: the difference between these products over a year is smaller than the cost of one night in an emergency hospital. PetSure’s claims data put the average tick paralysis claim at $2,402 in 2022, and the full breakdown is here. Price is not the variable worth optimising.

So which one

We cannot tell you what to give your dog — that is a conversation with your vet, who knows its history, its weight and where you walk. But the honest summary of the evidence looks like this.

• If you are organised and want one product doing everything: a monthly all-in-one — NexGard Spectra, Simparica Trio or Credelio Plus. Same drug class, same monthly rhythm, and all three cover heartworm as well as intestinal worms — NexGard Spectra and Credelio Plus add whipworm, Simparica Trio covers roundworm and hookworm. There is little to separate them. Dose whichever one you will actually remember, on the day it is due.
• If you know you will forget: longer-acting is safer than better-in-theory. Bravecto Spot-On at six months, or the Quantum injection at twelve, removes the failure mode that actually kills dogs. Two things to know about Quantum before the appointment: its APVMA label says it takes three days to reach full effect against paralysis ticks, so it is not cover for a trip you are leaving on tomorrow, and its safety has not been established in breeding, pregnant or lactating dogs.
• If your dog has a seizure history: talk to your vet about the non-isoxazoline options. Seresto is the most practical of them, but it is not the only one registered here — Advantix, Kiltix, Preventic and Permoxin are all outside that drug class too.
• If there is a cat in the house: anything except Advantix.
• If you have a puppy: check the minimums in the table. Credelio Plus starts lowest by weight at 1.4 kg; Bravecto Quantum is not for dogs under six months.

The thing worth repeating, because it is the finding that actually matters: the best product is the one that is still in date on the worst day of the year. Professor Stephen Barker of the University of Queensland put it plainly — “Just one missed monthly dose can mean a matter of life or death for a dog.” Every product in this table is registered for paralysis tick in Australia. The gap between them is far smaller than the gap between dosing on time and not.

Put the date in your phone as a repeating alarm. That is the whole trick.

Sources

• APVMA approved label — Bravecto Quantum injectable suspension for dogs
• Bravecto Australia — Spot-On for Dogs
• Bravecto Australia — product range and dosing intervals
• NexGard Spectra — Australian product information leaflet
• Zoetis Australia — Simparica Trio, registered monthly dosing
• Vet Practice Magazine — Professor Stephen Barker on missed doses
• PetSure — tick paralysis claims data
• Elanco Australia — Credelio Plus
• Elanco Australia — Seresto for dogs
• Elanco Australia — Advantix, including the cat warning
• US FDA — safety communication on neurologic events in the isoxazoline class
• Walkerville Vet — an Australian vet’s view on which preventatives work

This page is general information, not veterinary advice, and it cannot tell you what to give your dog. Registered durations and formulations change — always read the pack you are holding, and talk to your veterinarian about what suits your dog, particularly if it is very young, pregnant, unwell, or has a history of seizures.