Bravecto vs Simparica vs NexGard for Dogs: Tick and Flea Tablets, Weight Charts, Fake Tablet Checks and Seizure Precautions

Ticks are one of the biggest health threats to dogs in India. They spread tick fever (babesiosis and ehrlichiosis), cause anaemia and can even paralyse dogs. Modern chewable tick tablets have changed tick control, and Bravecto, Simparica and NexGard are now the products Indian vets recommend most often.

Here is how these medicines work, how long each lasts, how to choose the right weight band, how to spot fake tablets, and which dogs need extra caution.

How Do Isoxazoline Tick Tablets Work?

Fluralaner (Bravecto), sarolaner (Simparica), afoxolaner (NexGard) and lotilaner (Credelio) are isoxazolines. After your dog eats the chew, the drug is absorbed into the bloodstream and stays there for weeks. When a flea or tick bites and feeds, it swallows the drug. Isoxazolines block GABA- and glutamate-gated chloride channels in the parasite’s nerves, causing uncontrolled nerve activity, paralysis and death. These channels are far more sensitive in insects and ticks than in mammals, which is why the drugs are safe for dogs at labelled doses.

Because the parasite must bite to be killed, you may still see a few ticks or fleas for a short time. They die within hours. Bravecto starts killing fleas within about two hours and ticks within about 12 hours; Simparica kills fleas within about three hours and ticks within about eight hours.

Why speed matters for tick fever

Tick-borne parasites such as Babesia and Ehrlichia are passed to the dog while the tick feeds. Ticks usually need to stay attached for many hours, often a day or more, before transmission becomes likely. Killing ticks quickly therefore lowers the chance of tick fever, though no product is 100 percent protective, so check your dog for ticks after walks.

Bravecto vs. Simparica vs. NexGard

Which product is best depends on your dog’s age, the parasites common in your area, your budget and how easily you remember doses. A three-monthly chew suits families who forget monthly doses; a combination product suits areas where heartworm is common. Your vet can help you choose.

Choosing the Right Weight Band

Each product comes in colour-coded packs for different body-weight ranges. The ranges below are typical label bands; always confirm them on the pack sold in your area.

• Weigh your dog before buying, especially puppies, which can move up a band within weeks.
• Never split or crush a chew to share between two small dogs. The drug may not be evenly spread through the tablet, so one dog can be under-dosed and the other over-dosed.
• For dogs heavier than the largest band, your vet will combine packs to give the correct dose.

How To Give Tick Tablets Correctly

1. Weigh your dog and pick the matching pack.
2. Give the chew by hand as a treat, or hide it in a little food. Give Bravecto with or just after a meal, because food improves absorption.
3. Watch your dog for a few minutes to make sure the whole chew is eaten and not spat out.
4. If your dog vomits within about an hour, call your vet; a repeat dose may be needed.
5. Note the date and set a phone reminder for the next dose (one month or 12 weeks later).

Mange, Ear Mites and Other Uses

Beyond fleas and ticks, vets use isoxazolines extra-label (in a way not listed on the label) to treat several mite infections. They have largely replaced weekly amitraz dips and repeated ivermectin injections because they are safer and simpler:

• Demodectic mange (demodicosis), often seen in puppies and Indie dogs with patchy hair loss
• Sarcoptic mange (scabies), which is intensely itchy and spreads between dogs
• Ear mites, which cause dark, crumbly ear wax. See our guide to ear mites in cats and dogs.

Mange treatment usually needs repeat skin scrapings to confirm the mites are gone. Read more in our article on mange in dogs.

Side Effects and Seizure Precautions

Most dogs take these tablets with no problems. Possible side effects include vomiting, diarrhoea, reduced appetite and lethargy, usually mild and short-lived.

In 2018 the US FDA alerted owners and vets that all isoxazoline products can cause neurological effects in some dogs and cats, including muscle tremors, wobbliness and seizures, even in animals with no history of them. These reactions are rare, but you should:

• Tell your vet if your dog has epilepsy or has ever had a seizure. Your vet may still use an isoxazoline with close monitoring, or recommend a different product. Read about seizures in dogs.
• Contact your vet straight away if you notice trembling, stumbling or a seizure after a dose.
• Never give a double dose or combine two flea and tick products unless your vet advises it.

Simparica Trio and NexGard Spectra contain heartworm preventives, so dogs over about seven months should be tested for heartworm first. These products prevent infection but do not kill adult heartworms. See our guide to heartworm in dogs and cats.

How To Spot Fake Tick Tablets

Counterfeit and smuggled flea and tick products are sold online and in some pet shops in India. Fake tablets may contain no active drug, the wrong amount, or an unknown substance. Protect your dog by:

• Buying from your vet, a reputable veterinary pharmacy or the brand’s authorised distributor
• Being wary of prices far below the usual rate, loose tablets, or packs with foreign-language-only labels
• Checking that the blister is sealed and printed with the batch number and expiry date, and that these match the outer box
• Checking the box for the importer or marketer’s name and address and, where present, security features such as holograms or scratch codes
• Reporting it to your vet and the seller if ticks keep appearing on a dog that has had a “full dose”

Can Cats Use These Products?

Only products made and labelled for cats. Bravecto Topical Solution for Cats and Bravecto Plus are applied to the skin, and Revolution Plus and NexGard Combo are other cat options. Never give a dog tablet to a cat or use a dog spot-on on a cat. Many dog spot-ons and sprays contain permethrin, which causes tremors, seizures and death in cats. If your cat has been exposed, see a vet immediately.

Tablets Are Only Part of Tick Control

Brown dog ticks breed in cracks in walls, kennels and bedding, so a heavy indoor infestation needs environmental control too. Wash bedding in hot water, vacuum regularly, treat kennels and walls as advised by your vet or a pest-control professional, and treat every dog in the household on the same schedule. Our flea and tick prevention guide covers this in detail. If your dog suddenly becomes weak in the hind legs, read about tick paralysis.

Frequently Asked Questions

Which is better, Bravecto or Simparica?

Both are effective and safe. Bravecto needs only four doses a year; Simparica is monthly and Simparica Trio adds heartworm and worm protection. The best choice depends on your dog’s needs and your routine.

Can puppies take tick tablets?

Yes, from 8 weeks with products labelled for that age, such as Simparica Trio, NexGard or Bravecto 1-Month, as long as the puppy meets the minimum weight.

Why do I still see ticks after giving the tablet?

New ticks keep climbing on from the environment. They must bite to absorb the drug and usually die within hours. If ticks are surviving and staying attached, check the dose, weight band and product source with your vet.

Can I bathe my dog after a tick tablet?

Yes. Oral chews are not affected by bathing or swimming. Topical products need time to spread first, so follow the label.

Can I switch from one product to another?

Yes, usually when the next dose of the old product is due. Ask your vet about timing so your dog is neither unprotected nor double-dosed.

This article is for education and does not replace veterinary advice. Never give your pet any medicine, including human medicines, without your vet’s advice and dose.

Related Articles

• Can Dogs Eat Banana (Kela)? Serving Chart by Weight, Benefits, Risks and the Loose Motion Myth
• Flea Allergy Dermatitis in Dogs and Cats: Signs, Flea Life Cycle, Treatment and Prevention in India
• Apoquel (Oclacitinib) for Dogs: Uses, Dosage, Side Effects, Age Limit and Apoquel vs Steroids vs Cytopoint
• Amoxicillin, Amoxicillin-Clavulanate and Cephalexin for Dogs and Cats: Skin Infections, Wounds and Why Stopping Early Causes Relapse

References

• Howe S, Price M, Fung C. Bravecto for Dogs and Cats. PetMD, 2026.
• Howe S, Price M, Fung C. Simparica and Simparica Trio for Dogs. PetMD, 2026.
• US Food and Drug Administration. Fact Sheet for Pet Owners and Veterinarians about Potential Adverse Events Associated with Isoxazoline Flea and Tick Products. 2018, updated 2019.
• Bravecto, Simparica, Simparica Trio and NexGard prescribing information (MSD Animal Health, Zoetis, Boehringer Ingelheim).
• Fourie JJ, et al. Efficacy of fluralaner and sarolaner in the treatment of canine demodicosis and sarcoptic mange. Parasites & Vectors (multiple studies, 2015–2020).
• Companion Animal Parasite Council (CAPC). Ticks: General Guidelines.