How effective is Fluralaner (Bravecto) against external parasites?

Skin & CoatQ&AMeongsiljang Veterinary Advisory Board

Fluralaner is an isoxazoline-class external parasite medication that provides continuous protection against fleas and ticks for 12 weeks. We’ll cover its efficacy, precautions, and safety across different breeds.

What is Fluralaner (Bravecto)?

Fluralaner is an isoxazoline-class ectoparasiticide that works by blocking the nervous systems of fleas and ticks (specifically, glutamate- and GABA-gated chloride channels in invertebrates). The most important thing to know is that a single dose provides protection against approved parasites for approximately 8 to 12 weeks, making it a convenient option for pet owners who find it difficult to administer monthly treatments. However, the duration of efficacy can vary depending on the parasite and product; for instance, protection against certain hard ticks like Dermacentor may last around 8 weeks. Additionally, because this medication acts on the nervous system, pets with a history of seizures or epilepsy must be evaluated by a veterinarian before administration.

Which parasites is it effective against?

Fluralaner is a broad-spectrum medication that simultaneously targets various types of external parasites. It provides rapid efficacy against fleas and major tick species. Although not within its approved indications, veterinarians may prescribe it off-label for treating demodectic mange, sarcoptic mange, and ear mites. However, since it does not prevent heartworm disease, a separate heartworm preventive is required. Deworming medication is also needed separately for internal parasites.

Fluralaner vs. Other Isoxazoline Medications

Item	Fluralaner	Afoxolaner	Sarolaner	Lotilaner
Duration	12 weeks	1 month	1 month	1 month
Formulation	Chewable/Spot-on	Chewable	Chewable/Spot-on	Chewable
Use in cats	True	False	True	True
Flea & tick efficacy	Strong	Strong	Strong	Strong

Based on veterinary textbook evidence. Use of sarolaner and lotilaner in cats may include off-label use and may differ from domestic (Korean) approvals. For afoxolaner, cat-use data is not currently confirmed in textbook evidence. The final choice should be made after consulting your veterinarian.

How should it be administered?

It is recommended to administer Fluralaner with food. Giving it on an empty stomach can cause vomiting or gastrointestinal upset, so it’s best to give the medication right after your pet has eaten. Since the dosage varies by weight, be sure to have your pet weighed at the clinic and receive a prescription for the correct dose. The cat formulation is a spot-on treatment applied directly to the skin at the back of the neck. Do not crush or split the dog chewable tablets for use in cats.

A puppy taking a chewable medication from its owner's hand

Consult your veterinarian before administering to these pets

Dogs with a history of epilepsy or seizures may experience seizure induction after administration of Fluralaner. Caution is also advised for pregnant or lactating dogs, puppies under 8 weeks of age or weighing less than 2 kg, and dogs with liver disease. According to veterinary pharmacology textbooks, the isoxazoline class has been associated with reported neurological side effects; therefore, it is essential to closely monitor your dog for 24 to 48 hours after the first dose.

What are the side effects?

Most pets tolerate fluralaner well, but some may experience side effects. According to Plumb's Veterinary Drug Handbook, the most common adverse reactions are drowsiness, lethargy, and decreased appetite.

Gastrointestinal signs: Vomiting, diarrhea, and decreased appetite — these are relatively commonly reported.

Neurological signs: Muscle tremors, ataxia (staggering), and seizures — these are rare but require immediate veterinary attention.

Skin reactions: Redness or hair loss at the application site of the spot-on treatment — usually temporary.

Drowsiness and lethargy: Your pet may appear weak for one to two days after administration; this is among the most common side effects, often accompanied by decreased appetite.

If symptoms persist for more than 24 hours or worsen, contact your veterinarian immediately.

A puppy being examined at the animal hospital

Does efficacy remain after bathing or swimming?

Fluralaner oral tablets are absorbed through the digestive tract into the systemic circulation, so their efficacy is not diminished by bathing or swimming. However, for cats, if the spot-on treatment is washed off or gets wet within 48 to 72 hours after application, its effectiveness may be reduced. It is advisable to avoid shampooing or water play for at least three days after application. During seasons with high flea or tick activity, you may also want to review our External Parasite Prevention Guide.

Emergency situations — Seek immediate veterinary care

If your pet experiences seizures, repeated vomiting and diarrhea leading to suspected dehydration, labored breathing, or pale gums after administering Fluralaner, seek veterinary care immediately. Even if no symptoms are present, contact your vet right away if your pet accidentally ingests multiple tablets at once or if a cat chews on a chewable tablet intended for dogs. Bring the remaining medication packaging to help the veterinarian quickly verify the dosage.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

At what age can I start giving my pet Fluralaner?

This medication can be administered to puppies aged 8 weeks or older and weighing at least 2 kg. For cats, the minimum criteria are 6 months of age and a body weight of at least 1.2 kg. Kittens and young cats must receive a prescription from a veterinarian before use.

Can I give it again before 12 weeks have passed?

In principle, a 12-week interval should be maintained. Overlapping doses can increase the risk of neurological side effects, so if you miss a scheduled dose, consult your veterinarian to adjust the next appointment accordingly.

Can it be given together with heartworm preventive medication?

Yes, it is generally safe to use alongside most heartworm preventatives. However, when using multiple medications together, it's a good idea to inform your veterinarian about the ingredients and schedule to ensure there are no overlapping components.

Can I give this to Collie-type breeds (Border Collies, Shetland Sheepdogs)?

Although Fluralaner is not directly associated with the MDR1 gene mutation, Collie-type breeds can be sensitive to other parasitic medications, so we recommend genetic testing or consulting your veterinarian before the first dose.

Are there any other medications with the same active ingredient as Bravecto?

Yes, while Bravecto is the flagship product from FluRala, other products with similar active ingredients have recently come to market. Since products with the same active ingredient work in the same way, we recommend choosing the most suitable option for your pet in consultation with your veterinarian.

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References

[1] Blackwell's Five-Minute Veterinary Consult Clinical Companion, Small Animal Toxicology, 3rd Edition — Isoxazolines Chapter

[2] Principles and Practices of Canine and Feline Clinical Parasitic Diseases — Ectoparasiticides

[3] Feline Emergency and Critical Care Medicine, 2nd Edition — Flea Infestation Management