In or around November of 2013, a news report in Atlanta revealed that the tick and flea preventative drug Trifexis was linked to dog deaths.

Soon, groups on social media sprouted up claiming a link between the drug and more dog deaths.

Before long, it had been linked to over 700 dog deaths thanks to Trifexis posts on Facebook and other social media outlets.

As everyone knows, there’s a big difference between the truth and what’s on Facebook.

Unpacking the Trifexis story takes some doing, especially when you consider the rather alarming amount of misinformation and nonsense that’s out there.

So let’s stick to the facts.

What is Trifexis?

The best way to start is to determine what  it actually is.

Trifexis is sold as a chewable pill that kills heartworm, fleas, ticks, and other nasties in pets. It is made by Elanco, which is a division of Eli Lilly and Company. Eli Lilly and Company is an Indiana-based pharmaceutical giant, with products like Cialis and Cymbalta among their crop.

They are also the sole manufacturer of bovine growth hormone in the United States after having purchased the rights from Monsanto.

Trifexis purports to offer “three-in-one parasite protection” and is made from two key drugs: spinosad and milbemycin. Spinosad is an insecticide, one that first started to be used in the United States in 1997. Milbemycin oxime is a veterinary drug sold by Novartis, a Swiss drug company, as an antiparasitic.

So in essence, Trifexis is a pesticide combined with an antiparasitic drug and sold by a pharmaceutical giant.

What’s the Link to Dog Deaths?

The agency responsible for collecting information related to the “adverse effects of veterinary drugs on animals” is the FDA’s Center for Veterinary Medicine.

Anyone who’s ever attempted to navigate their “adverse drug event” database knows just how difficult it can be to find straight information, but apparently this field of numbers and details is used to make decisions about product safety.

According to some reports, there were about 660 deaths reported to the Center for Veterinary Medicine by pet owners citing the inclusion of Trifexis as either solely responsible or involved with the passing of their dog.

One report cites 392 of those 660 reports as “deaths,” while around 259 or so were euthanasia.

The difficulty in using the Center for Veterinary Medicine reporting system is that it’s incredibly complicated.

People report the passing of their dogs in all sorts of different ways, which makes understanding the reports a touch on the tricky side.There’s very little consistency.

Still, the links to Trifexis are real. There are stories from news outlets and Facebook pages that list a host of problems.

  • Everything from the inability of Trifexis to treat hook worms, to detached retinas immediately following Trifexis use can be found.
  • Vomiting is a commonly-reported side effect, while heart disease, lethargy and seizures, eye rolling and neck craning are also linked.

The Other Side of the Story

In light of this raft of reporting, it didn’t take long for Elanco to respond.

On Snopes, the veracity of Trifexis’ link to dog deaths is listed as “Undetermined.” The article cites a pathologist hired by Trifexis who found “no causative connection between the deaths of dogs who had reportedly died after being given Trifexis and the drug itself.”

Said pathologist was Dr. Jeffrey Engelhardt, who claimed that the deaths of three dogs in particular were linked to heart failure. The good doctor did not examine the dogs’ remains and only studied the pathology reports. Engelhardt worked with Eli Lilly and Company from June of 1985 to February of 2004 and is now with Isis Pharmaceuticals.

Elanco’s stated goal in examining the dogs and determining causes of death is to essentially let the company and the drug off the hook. That’s the starting point, which seems more than a little fishy.

The other side of the story, from the use of a not-so-independent pathologist to examine the dogs to Elanco’s stated determination, isn’t particularly convincing.

While one could dismiss hundreds upon hundreds of reports of dog deaths linked to Trifexis as anecdotal because of the appearance of “other potential causes of death,” one would also have to dismiss Elanco’s response as self-serving and, at least to some degree, misleading.

detox and strengthen your dogWhat to Do

If you used this product, I urge you to feed a good raw or home-cooked diet.  And, you must detox your dog’s liver.  This is our favorite way to detox and this is the only brand we recommend: Earth’s Natural Bentonite Clay

Poisons like these wreak havoc on your dog’s liver and immune system, opening him or her up to disease, pain and even death.

None of this is really new. Drug companies routinely look for ways to get off the hook in the same way insurance companies scour for information to refuse to pay claims. It’s how profit is made and it’s how business is done.

No matter how many glossy advertisements you see about this miracle drug or that miracle cure, the fine print is always more compelling.

But even the fine print is no substitute for common sense.It’s not safe to give your dog or any animal what amounts to a cocktail of pesticides and controversial “medicines.”

It’s not sensible to trust drug company information without checking sources. And it’s not reasonable to assume these monolithic giants have the best interests of you or your pets in mind.

There are other methods for treating fleas, ticks and heartworm (this is for prevention of heartworm only; not for dogs diagnosed with heartworm disease) that don’t require you to part with your hard-earned money for a product that is linked to so much harm. These methods are safe and natural, providing the best and healthiest way forward for you and your best friend.

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  • RA

    Perfectly healthy Labradoodle, my sweet 75 lb Kuma. Gave him another dose of Trifexis and the next day he refused food. Within 24 hours and 2 different vets, he’s home after bloodwork & IV fluids. I will be up around the clock this New Years Eve trying to keep him hydrated. Taking him back to 2nd vet tomorrow morning for more fluids. His RBC is dangerously low and his WBC high.

    • janie

      I am so sorry to hear this RA! What terrible news. This stuff is bad enough in small doses. Trifexis is mega doses of all these dangerous chemicals in larger doses and they want to call it safe.

      Give me a break. Again, I’m so sorry to hear about your dog. I hope he recovers. Stay natural. Use a product such as Triple Sure for parasite prevention. For heartworm (you only need this yearly if you live where it’s hot all year), use a natural product for that as well to prevent heartworm.

      We’ll be thinking of you.


  • Carolyn

    I have had the same problem, My beloved 16 year old Shih Tzu was in perfect health ( blood work drawn every 6 months preventative) Don’t know why I did it and I am heart broken that I gave my little man this pill on the recommendations of my vet . Kolbie became weak and unable to walk his liver enzymes tripled and he spent a week in the hospital getting continuous iv fluids, He was discharged to die. . My husband and I set vigil with him sub q fluids, syringe at a time of water.. We are now past the two weeks the third vet said he would be on this earth.. We did not force his medications on him, the last three days he has eaten ! His first meals in 3 Weeks.. and he is walking ( not rock steady but walking and his tale is wagging… Shame on this company and Shame on Drs who do not give the total information on this drug. I would love to take some advice as to the best natural vitamins/suppliant that will rebuild his strength and keep his liver detoxing. He has lost so much weight; He is very picky as to what he eats right now. We are just thankful he is eating.

    • janie

      Hi Carolyn:

      I’m so sorry to hear about your little old boy. This is truly heart breaking. They should not be pushing these dangerous drugs at all and especially to a senior dog. It’s sickening! Please remember that vaccines and chemical flea and tick products are just as dangerous.

      Lets start with diet Carolyn. Is he eating any solid foods or just liquid sub q?

      If I don’t get back right away this morning, I will get back to you a little later so don’t worry okay.


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