It has happened yet again. A safe and effective pet medication, the long acting flea and tick preventive, Bravecto, has been targeted by an unethical, unscrupulous reporter hovering like a vulture over grieving dog owners seeking closure over the unexplained deaths of their dogs, believing that Bravecto is the cause. Jim Strickland of WSB-TV Atlanta, the peddler of the past contrived heartworm and flea preventive Trifexis controversy, is once again all too ready to stoke the flames and foment outrage by sensatioanlizing the anecdotal reports of a few pet owners convinced the 3 month oral flea/tick preventive Bravecto killed their dogs. Not surprisingly, like the Trifexis fiasco, there is now a “Bravecto Kills Dogs” Facebook page.
Strickland begins early in his article stating about Bravecto, “It’s a dog chew so powerful that one dose can kill fleas and ticks for three months.” Of course, Strickland makes this statement clearly with no understanding of the pharmacokinetics (the physiological distribution, metabolism, and elimination of medications in the body) of Bravecto and likely no understanding of pharmacology and veterinary physiology, period. The unique characteristics of Bravecto’s active ingredient, Fluralaner, that make it long acting have little to do with how “powerful” it is, but more because of its unique molecular structure that allows it to pass through the canine and feline tissues unchanged.
This “unchanged” aspect of Bravecto is part of what makes it so safe. The primary organs of detoxification in the canine and feline, the liver and kidneys, are often responsible for elimination of all manner of waste products, toxins, and medications. When there is toxicity associated with the elimination compounds in the body, it is most commonly the act of the organs of detoxification metabolizing compounds for the sake of elimination that are damaging to the respective organs themselves, or toxicity associated with new forms (aka., metabolites) of given compounds that were altered for the sake of elimination.
Since Bravecto’s active ingredient passes through all tissues and organs unchanged and gradually gets eliminated from the body over time in the feces, there is virtually no taxing of the organs of detoxification, nor is there any generation of toxic metabolites. Bravecto is actually so safe, that it has no LD50.
The LD50 is required by the FDA for the approval of any medication. The LD50 represents the lethal dose at which 50% of laboratory test animals will die. In the case of Brevecto, the LD50 is listed at as > 2000 mg/kg. The reason it is listed at > 2000 mg/kg is because even at the ridiculous overdose of 2000 mg/kg, the test subjects were still not experiencing enough fatalities to reach an LD50 and the FDA subsequently waved this requirement for Bravecto. The average dog receives a dose of about 35 mg/kg once every 3 months.
Jim Strickland cites and FDA statistic of 355 cases of canine fatalities where Bravecto is “suspected” as a possible contributing factor in cause of death, but none have actually been proven. However, let us say for argument sake that the 355 cases were actually proven. 355 deaths canine deaths attributable to Bravecto among 34 million doses dispensed by Merck Animal Health since 2014 would translate to a dog having a 0.001% chance of dying from taking Bravecto.
To put that in context, a person is 20 times more likely to die in a plane crash, or a 30 times more likely to get struck by lightning; than a dog dying from a dose of Bravecto. If one puts that in the frame of reference that those 355 cases are “suspect” and not proven, it places Bravecto as one of the safest pest preventatives in the history of the veterinary ectoparasite preventative market history.
On the plus side, Bravecto not only is extremely safe for use in dogs and cats, it is also very effective in preventing the feeding of fleas and ticks on our pets. These pests torment our furry family members, cause skin infections and severe itch, and spread diseases such as the tick born Lyme disease bacteria. These pests also can feed on people leading to both nuisance and the spread of infectious disease to the human family.
It is preposterous to fear such a beneficial and safe preventative over anecdotal and unproven reports of death that do not align with the research and scientific data, not to mention the observations of veterinarians who respectively dispense thousands of doses of Bravecto a year. Of course, Jim Strickland does not care about science or facts and I am sure this will not be the last time we hear from him as he exploits grieving pet owners to peddle inaccurate and sensational stories that accomplish nothing but plant seeds of fear of helpful and safe medications, while sowing pet owner distrust of veterinarians.
Dr. Roger Welton is a practicing veterinarian and well regarded media personality throughout a number of subjects and platforms. In addition to being passionate about integrative veterinary medicine for which he is a nationally renowned expert, Dr. Welton was also an accomplished college lacrosse player and remains to this day very involved in the sport. He is president of Maybeck Animal Hospital , runs the successful veterinary/animal health blogs Web-DVM and Dr. Roger’s Holistic Veterinary Care, and fulfills his passion for lacrosse through his lacrosse and sport blog, The Creator’s Game.