This post contains affiliate links. As an Amazon affiliate I earn from qualifying purchases.Please read the Privacy Policy and Disclaimer

How Does Bravecto Work? FAQ’s

How does Bravecto work, and how do I know it’s going to be safe for my dog? Any responsible pet owner would ask the same questions, and for good reason. Like you, I don’t want to pump my dogs with chemicals that could make them deathly sick. There’s a lot more to consider, however, than the results of a few random studies.

Please read my privacy policy and disclaimer. I am not a veterinarian.
This post could contain affiliate links.

Bravecto has its fair share of controversy. Facebook groups like Does Bravecto Kill Dogs are filled with anecdotes from dog owners who’ve had tragic experiences with this drug.

Thousands of dogs, however, take Bravecto regularly with no problems at all. At the end of the day, you want to do what’s best for your dog. Bravecto isn’t the only way to kill fleas and ticks, which means you have other options.

You’ll read horror stories that err on the side of fear mongering, and promises from manufacturers that Bravecto for dogs is as safe as American apple pie. Frankly, if I thought my dog was killed by Bravecto I’d probably be on a mission as well! Luckily, I haven’t had that experience.

Let’s Talk about Bravecto for Dogs

I’m not a veterinarian, and I ask you to please talk to your veterinarian about the pros and cons of this drug. In the meantime, I’d like to share my thoughts on the topic along with solid information on what the drug is, what the FDA has to say about negative reactions to the drug, and other options you have for flea and tick prevention.

The goal of this post is to get you thinking critically about Bravecto for dogs. Educate yourself, talk openly to your veterinarian, and then decide for yourself what you want to do. I hope this helps.

How Does Bravecto Work?

Bravecto (fluralaner) belongs to a class of drug known as isoxazolines. Drugs that belong to this class of drug are absorbed into the bloodstream and then quickly settle into fatty tissue under the skin. Fluralaner, the active ingredient in Bravecto, works by settling into the fatty tissue of the dog.

Other flea and tick preventatives that fall under the isoxazoline class of drug include Credelio, Negard, and Simparica, which are all FDA approved.

The FDA has an awesome Animal Health Literacy Fact Sheet that you should read.

Bravecto changed the way we look at flea and tick prevention in our pets when it hit the market in 2014. With the promise of killing fleas and ticks within hours of ingestion, consumers jumped on board.

Watch this video on flea and tick medications.

I give Bravecto to my two dogs for fleas and ticks. Not only did it last at least 12 weeks, ticks literally fell off dead. If you live in a tick-endemic region, you understand completely how I feel about those disease-ridden things.

When the parasites swallow the Fluralaner, it creates dysfunction in the nervous system and prevents them from functioning normally. Bravecto can get fleas under control within 8 hours. Ticks, however, take a little longer at 24 hours.

It’s important to know that once these cycles of infestation are ended, they’re not going to come back as long as you keep up the quarterly dose.

About Merck Animal Health

Merk Animal Health, the manufacturer of Bravecto, considers the drug safe for dogs that weigh at least 4.4 pounds and for puppies from six months of age and up.

Merck is a company that develops, manufactures, and markets a variety of veterinary medicines and services. In addition to providing products and services for companion animals like cats and dogs, they also serve the larger farming community. For a full mission statement, please visit Merck Animal Health

How Does Bravecto Work Relative to My Dog’s Safety?

Before Bravecto hit the market, the product was thoroughly tested through rigid clinic trials. These clinical trials included the administration of doses 5 x the recommended amount.

Healthy adult dogs along with puppies were offered these high doses at 8 week intervals. This was done three times.

Here’s the thing: Clinical trials can only extend so far. It’s impossible to test every breed, size, age, and sex for adverse effects. Unfortunately, it takes a few years for a better picture of safety to emerge.

The FDA acknowledges that there have been serious adverse effects from the drug and they are currently (as of September, 2018) working with manufacturers to update their labelling.

According to the FDA, they want manufacturers to clearly state the risk of seizures and other side effects.

How Does Bravecto Work in Terms of Side Effects?

The most common side-effect of Bravecto for dogs includes sleepiness, weakness, diarrhea, decreased appetite, and flatulence.

If your dog vomits soon after taking Bravecto, you may need to offer another dose. However, please make sure to ask your veterinarian before you do that.

Once a dog vomits, it’s not a good idea to immediately try another dose. Ask the veterinarian how long you should wait and then try again.

If you dog continues to vomit (whether your dog gets another dosage or not), it’s important for you to contact the veterinarian’s office.

While adverse side-effects are not common, it’s important to know they exist. Bravecto in dogs has been known to cause seizures, even in dogs who’ve never had a seizure disorder before.

My Experience with Bravecto for Dogs

I give this to both of my dogs. However, I admit I hesitated the first time. Do I give them this chewy treat or not? I trust the veterinarian (who knows the dogs’ entire medical history) and know that my dogs have never had seizures.

Now, as I think back, I don’t believe the veterinarian or vet technician gave me any additional information on the drug. I was given some vague side-effects information but was told it was considered safe.

Luckily, for my dogs, it was. My dogs showed no obvious signs of any side-effects at all.

That said, from what I’ve read it seems that some dogs can develop side-effects later on in the course of treatment.

Your dog might take the first few doses with no serious event and then one day….there it is.

How Does Bravecto Work So Fast?

According to the manufacturer’s, Bravecto begins to kill fleas within two hours of taking the medication and kills 98% of those fleas within 12 hours.

The difference between Bravecto and other flea and tick medications is that it continues working for 12 weeks.

100% of ticks are killed within 12 hours of taking Bravecto.

How Does Bravecto Work on Pregnant Dogs?

Bravecto has been approved for use in pregnant, breeding, or lactating dogs.

Still, it’s important to know that studies can only go so far. It’s really the long-term use by many types of dogs that determine the true safety of any drug.

Reports sent to the European Medicine Agency indicate the possibility that Bravecto (administered to pregnant dogs) may have caused birth-defects and premature births in some.

How Long Does Bravecto Last?

Bravecto continues to provide effective flea and tick control for up to 12 weeks. Personally, I have found that it continues killing ticks for much longer than that.

Although I live in a tick-endemic province, I admit that I don’t give my dogs regular quarterly doses of Bravecto.

While keeping up with year-round dosing is considered the best way to protect your dog from fleas and ticks, I have discovered that the medication continues to work well into the fourth and sometimes fifth month.

Clearly, that’s my own observation and I’m not suggesting you stagger the dosing over a longer period of time.

Ticks are the biggest concern where I’m from. Here in Nova Scotia, ticks are EVERYWHERE and the number of dogs reported to be infected with Lyme Disease rises every year.

Fleas are more of a nuisance, although they can trigger allergic dermatitis in some dogs. Fleas still need to be kept under control, but ticks are the bigger concern for me.

I just happened to miss one of the three-month doses when I noticed that ticks were dropping off my dogs left and right. Now, before you decide to pull back on Bravecto dosage, you need to know that the drug does not kill the Lone Star Tick beyond 8 weeks.

In Nova Scotia, we’re more concerned with dog ticks and black-legged (deer) ticks because they carry Lyme Disease.

Watch this video for tips on how to manually remove ticks from yourself or your pets.

What’s the Cost for Bravecto?

Bravecto can only be purchased with a prescription and most veterinarians carry it in their clinics. Pricing ranges a little bit, depending on where you shop.

The following is a sample of prices based on a single, chewable dose of Bravecto for dogs based on a weight of between 20 and 40 kilograms, 1000 mg of fluralaner.

Pets Drug Mart









The list above is just a small example of the many places you can buy Bravecto for your dog. Remember, you can’t purchase Bravecto unless you can show a current, original, prescription written by a licensed veterinarian.

As you can see from the list above, prices average at about $40 per pill or so. Over the course of a year, you will spend approximately $160 for full flea and trick prevention.

Does the Humane Society Sell Bravecto?

The best thing to do is check with your local Humane Society office. If you’re interested, do a search for the name of your state or province and include the words “humane society”. Once you get to their website, you should see a button to Buy Meds.


How Does Bravecto Work on Heartworm?

If you’re still wondering how does Bravecto work, you should know that it works by settling in the fatty tissue of dogs just beneath the skin.

Bravecto works by poisoning topical parasites like fleas and ticks.

Unfortunately, Bravecto does nothing to kill heartworm, tapeworm, or any intestinal parasites. They require additional treatment.

Dogs get heartworms through the bite of an infected mosquito. Larva is passed through the saliva of the mosquito which then makes its way through the dog’s bloodstream. 

Heartworms live inside your dog’s heart, lungs, and blood vessels, often with little signs or symptoms in the early stages. 

Early on, you might notice an occasional cough without realizing there is a bigger problem brewing inside.

There are no oral chews like Bravecto available to treat heartworm. It’s important to talk to the veterinarian about a separate medication, especially if you live in an area where there are a lot of mosquitoes.

Read this to find out how to best treat and prevent heartworm in dogs!

How Does Bravecto Work on Mange?

Because of how Bravecto works in the dog’s body, it has been shown to be useful in treating localized and generalized demodicosis. Demodicosis infection is caused by mites in dogs.

These mites are microscopic and can live in your dog’s hair follicles or oil glands. These itchy creatures create a skin disease called mange.

Dogs with mange have inflamed and itchy skin combined with loss of fur. There’s more than one type of mite, leaving your dog vulnerable to a variety of mange forms.

The most severe type of mange is caused by the mite Sarcoptes scabiei (also causes human scabies). Luckily, mange is treatable. Systemic mange (generalized demodicosis) can be harder to get on top of.

Symptoms of demodicosis (mange) in dogs includes patches of fur loss or thinning fur, scaly skin, extremely itchy skin, and discoloration of the skin.

Young dogs and/or puppies are more prone to localized demodex between the ages of 3 and 6 months. In this case, the symptoms are mild and easily treated.

General demodex, however, is a systemic condition that can be brought about by a weakened immune system.

This is usually caused by an underlying illness that may or may not have been diagnosed.

I’m not a veterinarian and I can’t say for sure what he/she might do. However, based on what I know about mange in dogs, I suspect the veterinarian would try other ways to manage the condition if he/she thinks it can easily be brought under control.

Bravecto vs Advocate to Treat Mange

Bio Med Central, an open-access publisher, details a study that was done on Bravecto vs Advocate for the treatment of generalized demodex in dogs. The study used 16 dogs diagnosed with generalized demodectic mange and were divided into two groups.

One groups was given Bravecto® chewables at a dose of 25 mg/kg over a 28 day period. The other group was given the topical Advocate® which was divided into three doses at 28-day intervals.

The study was conducted, in total, over a 12 week period. During the study, mites were counted in skin scarpings and skin lesions were assessed on every dog before each treatment. These evaluations continued at 28 day intervals for the entire course of study.

Watch the video to tell when a dog has mange.

Results of the Bravecto vs Advocate Study

At the end of the study, Bravecto chewable tablets (one dose over 12 weeks) proved to be moderately better at treating mites on dogs than Advocate. The mite numbers from the skin scrapings were actually reduced by 99.8% on the 28th day of the study. By day 56 and 84, the mites were totally eradicated.

In the group treated with Advocate (topical applications administered once every 28 days for the full 12 weeks), mites were reduced by 98.0% on day 28. On days 54 and 84, the mites were decreased by 96.5% and 94.7% respectively.

What are the Ingredients in Bravecto Chews?

Bravecto chews contain the active ingredient known as fluralaner. This ingredient belongs to a class of drugs known as isoxazolines.

The discovery of isoxazoline compounds gave birth to the first oral flea and tick prevention medication. Fluralaner can be given as an oral chew or as a topical ointments on the back of the dog’s neck.

Fluralaner is an ectoparasiticide that belongs to the isoxazoline class. It works on the gaba receptors in insects, rendering them neurologically deficient and unable to maintain their normal breeding/life cycle.

Can I Get Bravecto from a Holistic Vet?

You can’t get Bravecto, the brand name for fluralaner, anywhere other than places legally entitled to sell prescription drugs. However, you might come across other types of flea and tick prevention methods that you feel safer administering to your dog.

Can I Use Holistic Methods of Treating Flea and Tick Infestations?

This might be a controversial thing to say, but I do not advocate for homeopathic or “natural” flea and tick prevention methods unless you live in an area where neither pest is much of a problem. However, something tells me if you’re reading this post, fleas and ticks are probably an issue.

The reason I don’t advocate for the natural methods (and, again, I’m not a veterinarian) is because they likely only kill adult fleas at best.

As you know, fleas just continue to reproduce. In order to totally annihilate fleas, you have to be able to get them at every stage. That means killing fleas before they lay eggs and get to the larvae stage.

I have a lot of experience dealing with ticks and I can tell you that, at best, you’re just going to annoy them with holistic tinctures. Seriously. Those things are beasts.

You cannot kill a tick by stepping on it because they have completely flat hard bodies that withstand it. You literally have to burn, suffocate, or poison them.

Yes, it’s disgusting, but protecting ourselves and our animals against Lyme Disease is the main priority.

What are the Alternatives to Bravecto for Dogs?

The best alternatives to Bravecto for dogs are any of the other prescription drugs on the market designed for this reason.

These medications include topical applications of K9 Advantix II (active ingredients are imidacloprid and permethrin. Permethrin is also found in household pesticides), Frontline Plus, Advantage (only kills fleas), Nexgard, Revolution, etc.

These medications have been on the market longer and are considered safe for dogs. Cats cannot metabolize permethrin.

This active ingredient would be considered poison for cats and would need to be treated as if they’d swallowed a deadly poison.

The list above is only a partial list. Your veterinarian can provide the best information based on your dog’s particular needs.

You can’t decide on the best alternative to Bravecto for your dog based on what someone else tried. Like us, every dog is unique with unique chemistry. Breed, size, age, underlying health conditions, allergies, and immune function all play a role in the safety of Bravecto in dogs.

Is Bravecto Safe for Dogs Who Carry the MDR1 Gene?

The MDR1 gene is a mutation that affects mainly herding breeds. These breeds are especially sensitive to certain drugs and could have serious adverse effects.

If you own a herding dog (or a mixed dog with suspected herd dog genetics) please talk to your veterinarian. He/she will be best versed in the safest medications to give your dog.

Can a Holistic Vet Provide a Bravecto Alternative?

Holistic veterinarians utilize a variety of techniques to treat companion animals including acupuncture, botanical medicine, chiropractic, homeopathy, massage therapy, and nutraceuticals.

There is definitely a place for holistic veterinarian practice and it’s certainly a good place to start if you’re worried about chemical flea and tick treatments.

 The Internet is ripe with DIY flea and tick treatments with questionable outcomes.

My own personal feeling is that you’re likely wasting your time, money, and energy on some of these. Yes, bathing your dog with certain ingredients might kill adults fleas or, at best, wash them away.

It’s impossible to shampoo all of the larvae and eggs off of your dog. Even if you did, it only takes one more flea to start the whole cycle again. And forget about ticks.

I have a ton of experience dealing with ticks and I promise you…shampoos and special essential oil bathes are not going to do the trick.

I Won’t Give My Dog Chemicals, So What Are the Options?

The best advice I can give you is to avoid ticks and fleas in the first place. If you live in a rural area, that’s going to be hard to do. It means keeping your animals inside most of the time (unhealthy for dogs) or checking your animals thoroughly each and every time they come inside.

That might be easier to do on small, short-haired dogs. However, if you have two big dogs like mine, you’re going to get pretty tired of being on 24/7 flea and tick patrol.

There are a few things you can do to help prevent fleas and ticks from getting into your house and onto our dog (and furniture).

Some of these methods include spraying your home with insecticide, vacuuming pets’ beds, furniture, carpets, etc. every day, manually removing ticks and checking for ticks everyday, use diatomaceous earth as a natural pesticide, etc.

Again, that’s simply my opinion. I’m not a veterinarian and I highly suggest talking with a licensed vet about your dog’s flea and tick prevention needs.

Arming yourself with as much information as possible is a good thing. It can all get pretty confusing though, so please don’t hesitate to ask your veterinarian questions. If you don’t feel comfortable asking the veterinarian questions, you’re with the wrong vet.

Do Essential Oils and/or Alcohol Kill Fleas and Ticks?

There is no evidence to suggest that essential oils provide effective treatment against fleas or ticks on dogs. In fact, you could be doing more harm than good.

Using rubbing alcohol and dish detergent on a regular basis, for example, can dry out your dog’s skin and aggravate and current skin conditions he/she may have.

When and How to Treat Healthy Dogs

The FDA recommends treating your dogs just before the beginning of flea and tick season. Flea season peaks during warm weather and that, of course, depends on where you live.

Dogs living in warmer southern climates require year-round treatment. Fleas love living inside where it’s warm and cozy so once

Tips for Using Flea and Tick Products *source CDC and FDA

-Read product labels carefully.

-Follow the directions exactly as noted. For example, if the product is specifically formulated for dogs, don’t use it on cats. As stated above, some chemicals like permethrin are essentially poisonous to cats.

-Once your pet has been topically treated with one of the spot-on flea and tick medicines, keep them away from other pets in your home for a few hours if possible.

The reason for this is just to prevent one animal from grooming another and ingesting the medication by accident.

-Watch your pet for a few hours after administering a topical solution (or feeding something like a Bravecto chew) for signs of adverse reaction.

This could include severe vomiting, diarrhea, extreme lethargy, poor appetite, depression or excessive drooling.

-If your dog has any kind of skin reaction to a topical solution, wash the product off with warm water and a mild soap and contact the veterinarian right away.

-Older dogs who are already dealing with chronic illnesses or weakness may not tolerate oral or topical flea and tick medications.

You should always have your dog assessed by a veterinarian before administering any drug.

-And lastly, make sure to wash your hands after applying a topical drug or wear gloves while using it.S

-Keep the product package after use in case side effects occur.

You will want to have the instructions available, as well as contact information for the manufacturer.

-If adverse effects do occur, you should report them to the National Pesticide Information Center at 1-800-858-7378.

Of course, the first thing you want to do is get your dog treated ASAP. Later, make sure to also report the adverse effects to the manufacturer. Manufacturers like Merck have a legal obligation to report these side effects to the FDA.

How to Report Adverse Effects

You can report adverse side effects of Bravecto or any other medication (prescription or over-the-counter) directly to the FDA.

Not able to get in touch with your veterinarian right away? Phone the National Animal Poison Control phone number at 1-888-426-4435. Please be aware that the NAPC may charge a fee for services.

How Does Bravecto Work in Dogs? A Summary

Bravecto, a one-of-a-kind drug created by Merck, is a long-term solution to a nasty flea and tick problem.

Although considered safe for the majority of otherwise healthy dogs, there have been really serious adverse side effects reported. These side effects include severe vomiting, diarrhea and death.

Before administering any drug to your dog, you should always clear it with a licensed veterinarian. I hope this post has given you something to think about in terms of whether you might give Bravecto or not.

There are, as you’ve read, lots of other prescription options. The cost of Bravecto is comparable to other medications in the same class. The difference, however, is that you only need to purchase a chew once every three months rather than monthly.

The main thing I want to leave with you is that Bravecto is considered safe for most dogs. However, it’s best to use caution and ask questions.

There have been serious events reported; however, that can be said of all prescribed medications for dogs.

At the end of the day, we all want happy and healthy dogs. Protecting them from disease-carrying parasites is one of our top priorities. Unfortunately, that comes with inherent risks.

The best way to mitigate these risks is to have an open dialogue with veterinary professionals. The goal of this post wasn’t to tell you what to give your dog. Instead, I want you to think about the options and not be afraid of asking questions.

I hope you were able to get a lot of useful information from this post! Please let me know if I’ve left something out or if you read something that you don’t believe is correct.

I’m not a veterinarian, so I really want to make sure that I’m offering the best information possible.

Feel free to contact me directly at [email protected] or leave a comment below.

If you enjoyed this post, please POST, TWEET, OR PIN!

Scroll to Top