Does Bravecto Kill Dogs?

What if common treatments recommended by your vet are causing deaths in dogs and cats?

‘Does Bravecto Kill Dogs?’ is a popular Facebook group with over 25,000 members dedicated to fighting the use of the popular 3-monthly flea control.

If you visit you’ll see story after story of sicknesses and deaths occurring in dogs who have received Bravecto. Symptoms include:

  • Kidney and liver failure
  • Seizures
  • Skin rashes and sores
  • Acute pancreatitis
  • Bloody diarrhoea
  • Immune-mediated anaemia
  • Death

What’s the truth? Can this product really be causing these illnesses and deaths? If so it’s a disaster. Bravecto is one of the most commonly used treatments in pet dogs and cats on the planet.

What’s worse, this follows close on the heels of the Beneful and Trifexis controversies.

Are Pet Drugs & Medicines Dangerous?

How is it that people can be so sure a drug is dangerous while vets say the same drug is safe?

Vets will say:

  • I know these treatments well
  • I recommend them for my own patients
  • The drugs have been tested in clinical trials at far above normal doses
  • If a drug was dangerous, I would know
  • If a drug was dangerous, it would be recalled

Campaigners will say:

  • How do you explain all these animals who have got sick after taking the drug?

What about all these illnesses? How do we know if they are being caused by Bravecto?

The first thing is that no one is being malicious; there is no scam or hoax. These illnesses really happened. That’s not in doubt.

  1. Some of the reports will be true, representing the percentage of adverse reactions we can expect with any treatment.
  2. Most will be explained by the phrase drummed into me in statistics classes: “Correlation does not imply causation“. What does this mean?

A good example is the long-acting antibiotic injection Convenia. Here’s a very common real world scenario:

  • A cat comes in very sick, and clearly in danger. We can’t make a diagnosis from the physical exam, and need to order blood tests.
  • It’s not an option to do nothing while we wait for the results. If we can give pills we will, but that’s very difficult and stressful for many sick cats. Therefore we often recommend Convenia.
  • Now let’s say the worst happens and the cat gets worse or even dies. Was it the Convenia or the underlying disease? We simply don’t know. Convenia’s use is correlated with the death, but is not necessarily causative.

cat hind paresis

Here’s one where I was fooled.

Yuki was almost paralysed in the back legs after a routine vaccination. I absolutely believed the vaccine had caused it. Who wouldn’t?

I will always be thankful that her owners took her to a specialist for an accurate diagnosis. She actually slipped a spinal disc in her cat box during transit.

If it wasn’t for the MRI I would have spent the rest of my career thinking vaccines cause paralysis. That’s how hard it is to know what’s safe.

For another view of the correlation-causation problem, have a look at these graphs. Who knew that eating cheese was correlated with being strangled by your bedsheets, or that when Nicholas Cage is in more films there are more swimming pool accidents? It’s true!

Sickness in animals is common enough that there will be many, many times when they are simultaneously on another treatment like Bravecto when they get sick. That’s not in doubt. The big question is: did the Bravecto cause the illness or would it have happened anyway?

Let me put it another way. Let’s say a dog gets sick once a year, so there’s a one in 12 chance a dog will get sick in any month. Therefore one in twelve dogs will get sick within one month of even a yearly treatment like ProHeart or a vaccine. The people whose dogs get sick may associate the sickness with the treatment, and they won’t be aware of the other 92% of dogs happily going along normally.

These events, whether rare or common, will be easily brought together by online groups. It’s the job of the regulators to decide if such events represent the standard rate of illness in the community or occur more commonly when taking the drug.

How Do I Report An Adverse Effect?

One thing that frustrates me is the misunderstanding of the reporting and recall system. Reporting is how we collect these events to look for patterns in the data

That’s how unknown side effects are discovered and known side effects are monitored.

Every suspected adverse effect should be reported to the manufacturer and your country’s veterinary medicine regulator. Here is the link for the APVMA in Australia.

The regulator is then legally bound to make a record of each report.

Here’s where the online campaigns are interesting:

  1. They encourage every suspected adverse effect to be reported. That’s no bad thing, but if you look at the lists you’ll even see symptoms that are almost certainly from the disease being treated not the drug. For example, skin problems for flea products.
  2. They then use the same list they had a big part in making to say: “Look how many adverse effects have been reported; we need a recall “.

Here’s what they say on ‘Does Bravecto Kill Dogs’.

“IT DOES NOT NEED TO BE PROVEN TO BE AN ADVERSE REACTION. A coincidence of timing, soon after drug administration is enough to warrant that SUSPICION.”
wwww.facebook.com/doesbravectokilldogs/ Sept 2016

Why Doesn’t The FDA Do A Recall?

I think they learned their lesson with the Proheart debacle. That was the first time one of these online campaigns achieved significant momentum, and they DID recall the drug.

Continued use in Australia and Europe showed Proheart to be safe and it was re-released in 2008 in the USA.

That doesn’t mean reporting problems is a bad thing. We do it all the time and it’s a big part of keeping veterinary drugs safe. There isn’t a drug on the planet that doesn’t have a list of known adverse effects.

The trick is that the raw data needs analysis before it can be used.

  1. Are adverse effects happening more commonly in treated animals?
  2. If so, is the extra risk small enough to be justified by the benefits?

Using just raw data or a gut feeling to support a claim is not accurate enough, as I hope you can now see.

Why Are Online Campaigns Successful?

Online campaigns are usually run by very passionate believers. The passion comes through in how they speak about:

  • The terrible things that have happened to pets
  • The dangers of big pharmaceutical companies
  • Conspiracy and denial by vets

They also actively suppress alternative points of view on the pages and sites they manage.

They do all this out of a deep conviction that they are saving lives.

Contrast this with how vets and regulatory bodies need to act. We need to choose our words carefully and stick to the provable facts. It makes us look boring at best, or disinterested or even in denial at worst. We also tend to avoid talking about money even when it’s in our interests to do so.

Here I go then!

  • Vets receive no payments from drug companies
  • Recommending a deadly product isn’t exactly good business sense
  • Most vets are employees & have no financial incentive in the products they sell
  • Even when they do the rewards are pitiful: last year my Bravecto sales amounted to 0.25% of turnover.

Why Does It Matter?

Here are three good reasons:

Loss Of Treatments

We battled heartworm in Adelaide throughout the eighties and nineties with only limited success before Proheart arrived. Then within six months of the yearly injection’s release in Adelaide, heartworm disease in dogs went from common to rare.

Vets in the USA are still having problems controlling this disease, and I have to ask if it could all have been very different.

How many dogs died after Proheart was withdrawn who would have been saved? We’ll never know, and the same will happen when any valuable drug gets taken off the market.

Needless Suffering

I saw a dog recently with heart disease who can’t even go for walks or climb stairs. The shocking thing is that I saw the same dog with the same symptoms a year ago and recommended a good heart treatment at the time.

Little did I know the owner went home, did an internet search and found a site dedicated to the evils of the drug. So out of fear she did nothing and her dog suffered. It’s a terrible irony that the people who care the most for their pets are also often the most vulnerable to misinformation.

If you think pets with fleas don’t suffer, you need to read about the death of my Auntie’s dog Rufus. It’s at the start of our guide to the alternative & natural flea remedies.

Vets Care

Yes, this is also personal. Who among our readers isn’t a perfectionist at work? I don’t know one vet who doesn’t care deeply about the effect they have on their patients or would do deliberate harm. We can at least agree that we’re all on the same side.

Let’s be open about the risks of adverse effects, and let’s also be prepared to change our views based on the evidence. Yes, there will be times when new drugs are found to cause harm, but we have to approach the problem logically or it’s back to the dark ages.

Related: Vet Stress And Suicide. How To Research And Use Science

Have something to add? Comments are welcome (if not of an abusive or personal nature) and will appear within 24 hours of lodging.

By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on Facebook and Twitter. We do not accept payments or incentives in return for stories. Like or follow our page or subscribe via email to read the latest.
Have something to add? Comments are welcome below and will appear within 24 hours of lodging.

Andrew

30 Replies to “Does Bravecto Kill Dogs?”

  1. So can anyone give me any advice on what to give our beloved fur babies to protect them. Every product that I looked into seems to advise me of the same dangers

    1. I can tell you whoever makes Bravecto is ripping people off with the new range. The cat and dog liquid tubes are identical but the dog cost more for 1 tube than the cats 2 tubes…. Robbery on a commercial scale. Put the packs side by side and see for yourself. I was given the heads up by a vet. A smart fur parent would buy the large cat and get 1 years protection for a medium dog. As a good poodle parent I have found this cheap option a way to keep my muffy safe for a whole year at a 1/4 of the price last year!!!! Sam

      1. Interesting! It’s not an uncommon practice for pharmaceutical companies to price their products more on what the market will bear that on the actual cost per unit of drug. This could be another example, but care is probably warranted in case the vehicle or concentration or some other ingredient is different.

  2. Here is a list of adverse reactions to a drug. Can you guess which one it is?

    Serious Reactions

    anaphylaxis/anaphylactoid rxn
    angioedema
    bronchospasm
    bleeding
    GI perforation/ulcer
    DIC
    pancytopenia
    thrombocytopenia
    agranulocytosis
    aplastic anemia
    hypoprothrombinemia
    nephrotoxicity
    hepatotoxicity (high-dose ASA use)
    salicylism
    Reye syndrome

    Common Reactions

    dyspepsia
    nausea
    vomiting
    abdominal pain
    tinnitus
    dizziness
    hyperuricemia
    bleeding
    ecchymosis
    constipation
    diarrhea

    Those of you who guessed Aspirin (acetylsalicylic acid) are correct. Does this make aspirin a bad drug? No; it has healed millions of aches and pains and helped millions with heart disease. It does mean that even the safest of drugs can have adverse reactions. In the vast majority of cases, the benefits of using the medication outweigh the risks of using it, as is the case with Bravecto in most pets. Using Bravecto prevents many unpleasant and potentially life threatening diseases such as Lyme disease, Anaplasmosis, Erlichiosis and Flea Allergic dermatitis to name a few. It also prevents your pet from bringing live ticks into your household which could bite humans and inflict diseases such as Lyme disease.

    Ask questions of informed and educated professionals. Don’t be swayed by social media hype. Veterinarians are here to help you and your pets. As veterinary salaries are usually less than nurses and teachers, we are certainly not in it for the money.

  3. I want to give my dog bravecto, she is 7 years old and weighs 1.350 kg
    How by weight pill do I give her
    Thank you
    Daniel

    1. Hi Daniel. That’s one tiny dog! I’m afraid that they don’t make a Bravecto for dogs under 2kg. I would recommend Revolution Pink (puppy & kitten) for this size dog which also includes heartworm prevention

  4. I only became aware of Bravecto at the Vets today. It sounded good but I decided to search it on the net. After what I have read I am not willing to take the risk. My dog means too much to me.

    I will continue to use Frontline.

  5. My dog had a severe skin allergy due to fleas and was tearing himself apart ,with the help of steroids,antihistamines and bravecto it is finally under control and Kaiser is a happy dog again, but I have been slammed by people for giving him bravecto because of horror stories my argument to them is Kaiser was much worse off before bravecto and as with any drugs even in human drugs there are side effects to all some it affects badly some not and also im sure a vets would not sell their customers a drug that would kill their pet anyway my dog has been on bravecto nearly a year now and has been fine so if it works dont fix it .

    1. Wait 2 years and see if his labs are elevated! After my dog took it for 2 years he was diiadnosed with pancreatiiis then he had a anal mass remove 5/14/217 and he passed away 2/6/18

  6. Have you seen the new report from the EMA? Merck is going to be required to add a seizure warning to Bravecto in Europe. So maybe all of these people in Facebook were not wrong after all. And maybe they should add a death warning since dogs have developed seizures after it and died.

    1. Thanks Jennifer. Yes, completely agree. Seizures are suspected of being made more likely in dogs taking this class of drugs and we do not recommend their use in dogs prone to seizuring. Up to now interestingly, these label advisories have not appeared on Australian product. Bear in mind though that seizuring in dogs is common and these are only case reports so more work is needed to prove a causal link. However, prudence is best in the meantime.

  7. Andrew your ability to write an article without excluding any piece of information from anyone, as long as there isn’t intended malice, is refreshing and speaks volumes of you as an open minded insightful academic – to that I salute you. No individual is to feel threatened and all facts without inflammatory projection are invited. This is the only way to create a discussion where boundaries and opinions are removed and knowledge is gained. Great article – really well written.

  8. Thank you for such a well written article Andrew. I have been struggling to explain the “correlation vs causality” conundrum with my staff and clients. Now I will just get them to read this!

    1. When you watch your dog who means the world to you and you raised and cared for all his life. Who was the dog of all dogs… I mean do you understand a actual relationship with a dog. NOT JUST ONE DOG BUT 2 OF MY DOGS. I HAVE SPENT 1,000’S ON VET BILLS. ONE JUST DIED TODAY AND THE OTHER WILL NEVER BE NORMAL. I know I’m talking to you Merck. quit the BS …OK ANGEL WINGS ARE ON…oh gosh you guys are so wonderful saving all the little dogs with your wonderful products at the mere rate of approximately $50 a pop..at the rate of selling some. 340 million pops!! OMG (oh my! Now that’s somewhere in the billions of dollars isn’t it? I can see you truly speak from your heart and anyone on your wagon sings the song of songs. We the keeper of the dogs who make life so much more will keep after you. For you see , we see and we know. DO WHAT’S RIGHT PEOPLE YOU’LL FEEL MUCH BETTER ABOUT YOURSELVES. GET OFF THAT WAGON SMALLER GUYS. DO IT FOR THE DOGS …YOU ARE KILLING THEM. MAKE FRONTLINE WORK AGAIN IT’S A MUCH SAFER PRODUCT

  9. Brilliantly written post Andrew. It always puzzles me why people are so willing to believe information from those with often no qualifications or formal studies in science, medicine, veterinary, etc. and yet won’t believe information provided by those who have spent years studying. Do they perhaps believe that all of those years studying has in fact stunted your brain so that vets and MD’s willing follow perceived lies peddled by ‘Big Pharma’? Don’t they realise that all those years of study have in fact developed your knowledge and understanding to the extent that you would be far less likely to blindly accept unproven and dangerous assertions? Which I might add is exactly what often happens on social media – people with no formal studies in an area making assertions and sharing information from ‘dodgy at best’ sources. And why would they think a vet would ever knowingly prescribe a drug that would harm one of their patients? Have they never met or spoken with a vet and realised the level of compassion they have for animals? I’m not a vet btw but I completely share your and many other’s frustration with this and similar situations. Keep writing, informing and educating and maybe pet owners will find your factual information online rather than the opposite!

  10. I am also providing you with factual information on seizures. Are you aware of the new topical form of Bravecto? The manufacturer has released warnings that it can cause seizures in dogs that never had them before. However, they have not changed the product warnings for the oral version. This is very concerning since seizures are amongst the top 10 side effects reported to the FDA.

    This is from the product warning for the new topical:

    Important Safety Information (Dogs):
    The most common adverse reactions recorded in clinical trials were vomiting, hair loss, diarrhea, lethargy, decreased appetite, and moist dermatitis/rash. Bravecto has not been shown to be effective for 12-weeks’ duration in puppies less than 6 months of age. Bravecto is not effective against lone star ticks beyond 8 weeks of dosing. For topical use only. Avoid oral ingestion. Use with caution in dogs with a history of seizures. Seizures have been reported in dogs receiving fluralaner, even in dogs without a history of seizures.

    (link broken-removed)

    Here is another report to the EMA with the NCA recognizing that seizures are possible:
    Reason for treatment: unknown SAR: One dog received Bravecto 1000mg on 28 Apr 2015 in the evening according to the leaflet. 2-3 hours after administration the dog showed an epileptic seizure and another seizure the next morning again. It was brought to the vet in lateral recumbency and with tonic-clonic seizures. The animal was treated symptomatically with diazepam. Pexion was given for home-treatment. The dog is not a known epileptic. FU pending. Follow up from 26 Mai 2015: On 30 Apr 2015 the dog was presented to vet again, again it showed seizures. Worsened, then euthanasia in a vet clinic on 01 May 2015. Unknwon reason for seizures, but suspicion of tumor, vet does not see a association to Bravecto. No autopsy. [Reason for use for product: Generic: FLURALANER CHEW TABLETS Brand: BRAVECTO 1000MG 1X2TAB EU1 Reason: Ectoparasitic control] [State of health: Unknown]

    NCA Assessment:
    Time connection is reasonable, because 2-3 hourse after administration the dog showed seizures. Neurological signs are a possible adverse event after use of this product. Similar cases have been reported before. Other explanations are possible, but not confirmed. The vet assumed a tumor, but an examination was not performed. Therefore a product relationship is possible.

    1. Thanks. Yes we are aware of avoiding the drug in patients at risk of seizures. We do not have the topical (spot-on) form in Australia and it is unlikely we would recommend it if it arrives when there are very good alternatives available.

      1. Thank you, but the new topical which includes the same ingredient as the oral mentions it is a risk in dogs with no history of seizures. And there are absolutely no seizure warnings for the oral. Even in dogs that have a history. They have that warning for Nexgard not Bravecto.

        1. Thanks Susan. The way vets see it is that if one of a class of molecules is associated with an adverse effect then it’s prudent to look for it with the others. They will still differ of course; for example, ivermectin and selamectin are both avermectins but only ivermectin harms dogs with the MDR-1 mutation.

      2. At my vets the vet nurse sells this drug, not the vet and I asked her and she doesn’t warn people about not giving to their pet if they are at risk of seizures. She didn’t know. To me this is an irresponsible practise. How many other vet surgeries are the same? This drug should be more strictly prescribed. We got to our vets for help and advise otherwise we may as well just buy at the pet shop or online. What do you think Andrew?

        1. Hi Carol. Interesting question! In Australia, product labels for Bravecto do not warn of use in dogs prone to seizures. Therefore the nurse you spoke with was giving correct information. I believe the initial concerns were due to a number of seizures seen in dogs in the USA during the trial stage of Nexgard, a related compound. My feeling from reading the reports is that these dogs’ seizures were randomly occurring and not related to the Nexgard but it has made vets wary of the use of the entire class in seizuring dogs.

  11. This is vety well written. I just want to point out something. When you mention skin reactions, you correlate it to the issue being treated. I just want to make sure you are aware that many of these dogs were not reporting any skin reactions or fleas before hand. They took this as a preventative measurement and then they ended up with skin issues. And even the European medicine agency is recognizing that allergic skin reaction’s can result afterwards

    Here is an example.
    REPORT TO THE EMA
    Reason for treatment: Ectoparasitic control SAR: A dog was treated with Bravecto 1000 mg approx in Jun 2015. Approx some days – 1 week post application it showed itching, at inner thigh and belly which worsened. Dog presented to vet 14 days post application due to this reaction, vet treated dog with Depot-Medrate, Cortisel. Low grade improvement, but still reddening of skin, inflammation of skin, pustules (purulent), itching. Now (23 Jun 2015) the tail is affected, too. Diagnostic: skin punches for differential diagnostic. No food allergy or other allergies known. Follow up form 13 Oct 2015: The result of skin punches show an eosinophilic granulocytes, possibly because of an allergic reaction due to contact, i.e. flea, food, atopia, sarcoptes. The vet reported that the dog has a very sensitive skin, also reacts on other topical ectoparasiticides and showed allergy every August, but never as high-grade as this year. Vets opinion is that the Bravecto worsened the situation. Now recovered. FUP from 08 03 2016: The dog died approximately in Dec 2015 (onset of symptoms about 5 months) . Attending vet tentative diagnosis was an intestinal involvement, dog was forwarded to a vet clinic. Tentative diagnosis was not confirmed, but dog died next day. No pathological examination available. Attending vet’s assessment is ?N?. In Mar 2016 the owner told to another, competitor vet that the dog died because of treatment with Bravecto. [Reason for use for product: Generic: FLURALANER CHEW TABLETS Brand: BRAVECTO 1000MG 1X1TAB EU1 Reason: Ectoparasitic control] [State of health: Unknown]

    ASSESSMENT ON EMA REPORT:
    Time connection is reasonable, because a few days after administration of tablet the dog showed skin reaction. Allergic reactions are a possible side effect. Skin reactions are a follow of allergic reaction. The pharmacological-toxicological profile is fitting. The reason for the death of dog is unexplaned. Very few information is provided and therefore not to assess. In total the case is assess with “B”.

  12. After our visit yesterday, and as you are aware I had previously seen these various ‘Anti-bravado campaign sites’ which in my opinion aim to share potential users for their pets and whom are administered usually by lay people. Sorry.

    Out of my own need to know and interest prior to visiting the surgery I researched and analysed various journal articles on the NCBI journal site. One which we discussed.

    In reflection, it could be assume those who have been treated may have had an adverse affect possibly due to an underlying medical condition (like my 11yr old girl with DCM). Its only a hypothesis in the end.

    The Australian Government body APVMA does clearly outline ‘Compliance and enforcement’ for all users of chemicals and approve medical drugs ( agricultural or veterinary ) including any recalls to ensure a quality assurance program for their consumers.

    Goodness this happens daily with food we buy at the local shopping center (glass found in…..or E-coli in over seas frozen fruits etc)

    Dear, dear and to think most of the general public go to a family doctor today, and expect to walk out of the doctors surgery with a script in hand without asking what, why, how and when to come back!

    Jo

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