The key ingredient found inside Bravecto is Fluralaner, which is ingested by your pet orally through a chewable tablet and then travels through your pet’s system.

Vomiting – Although Bravecto has shown to be readily eaten by most pets immediately through the chewable tablet even without mixing it food, there is a chance of it causing your pet to vomit. This may be due to your pet having an upset stomach before even ingesting the chewable tablet to which the new medicine may have caused a reaction.

Diarrhea – Alongside the likes of vomiting, diarrhea is another side effect that can be triggered by Bravecto. Pets have different stomachs; some have strong ones, while others work with the very fragile ones, the ones that tend to be very picky about what they eat. Bravecto’s chewable tablets may not sit well with very weak stomachs or those with pre-existing tummy conditions.

Other side effects -

  1. Appetite Changes – Just like any other medicine, Bravecto may induce changes in your pet’s appetite, and more often than not, it will decrease it and make your pet reject food for a certain amount of time. This is due to the introduction of the drug into your pet’s system.
  2. Thirst Changes – Another side effect that can be induced by Bravecto is to your pet’s thirst, albeit making them have an excesstive thirst for a certain amount of time. Although it really depends on your pet and how well they take to Bravecto, in the majority of cases that were reported, pets had an increased water intake for about 30 minutes to 1 hour after taking medicine.
  3. Weakness – In the most serious cases and also the very improbable cases, your pet may experience weakness after taking Bravecto.
  4. Hair loss - caused by the active ingredient fluralaner, and dogs should be bathed regularly in warm water and fed a moist diet to hydrate the skin. Please consult your vet if your dog is itchy and distressed.
  5. Dehydration
  6. Panting
  7. Skin colour changes

There's also the MDR1 mutation which has also been found in Shetland Sheepdogs (Shelties), Rough Collies, Australian Shepherds, Old English Sheepdogs, English Shepherds, German Shepherds, Long-haired Whippets, Silken Windhounds, and a variety of mixed breed dogs.

In 2015 a Facebook post claimed that Bravecto chewable flea and tick remedy is fatal to dogs. A family who had adopted a dog from Pet Helpers asserted that the dog had died as a result of being given Bravecto chewables and that another of their dogs had also nearly died.

However, studies at the time suggested that Bravecto was safe. But that's not the end of the story. Following thousands of adverse reaction reports, Bravecto remains a potential cause for concern.

As the warning spread on social media during 2015, it was picked up by the website Snopes, who attempt to confirm or quash various 'rumours'.

Investigating the claim, Snopes quoted a 2014 study published in the Parasites & Vectors journal where 32 beagles were treated with Bravecto (fluralaner) and no serious adverse side effects were attributed to the medication.

The full study can be found here.

Wilson Street Veterinary. Dr. Michael Mogavero stated that the drug had been extensively tested prior to its release and had proved safe for dogs - click here.

Snopes concluded that the Bravecto rumours were 'unproven'.

The family of the dog asserted that one of their pets had died within a day of being given Bravecto chewables and that another of their dogs had nearly died after being given the same treatment at the same time. The update also asserted that Bravecto chewables were responsible for the dog's death and that several other dogs had died of liver and kidney failure shortly after taking the same medication.

As of August 2018 - The European Medicines Agency (EMA) reports that there were 8,692 adverse reactions after the administration of Bravecto. And there were 2,056 reported deaths.

The US Food and Drug Administration (FDA) issued a warning on September 20, 2018 about the isoxazoline flea and tick products fluralaner for dogs and cats (Bravecto®), afoxalaner for dogs (Nexgard®), and saroloner for dogs (Simparica®). The recently introduced isoxazoline, lotilaner (Credelio®) for dogs falls into this same class.

Dogs and cats with no known prior medical history of muscle tremors, ataxia, and seizures have experienced those adverse reactions to this class of flea and tick preventive pesticides.

The MDR1 gene mutation undergoes one or more mutations that allow a higher absorption of drugs and toxic substances to enter the central nervous system and then they can breach the blood-brain barrier and create adverse reactions. This is very serious when you're considering flea and tick medication for these breeds. 

With all this mind, some pet owners don't believe that Bravecto chews are worth the risk.

If your pet experiences a bad reaction from any spot-on product, immediately bath with mild soap, rinse with large amounts of water, and call your veterinarian.


This information is not meant to be a substitute for veterinary care. Always follow the advice provided by your veterinarian.