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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Showing 20 comments
  • Andrew Lazzers

    I have a 6 month old mini doxie and at the recommendation he take Trifexis. Since he took it he has been vomiting every 3 to 4 hours. Any recommendations on how to keep him from vomiting? Or any ways to detox him?

    • janie

      Hi Andrew:

      I would use the following Bentonite Clay. I would also feed a species appropriate diet that includes real WHOLE foods and meats. This is about more than detoxing. You now need to build his immune system.

      Bentonite Earths Clay

      I would use the clay for four months daily feeding 1/4 teaspoon per meal. Do not feed in a metal bowl or use a metal spoon to stir the clay into the food. The clay absorbs all toxins including metal and you don’t want this going into your dog’s body. Use a glass or ceramic bowl and a plastic spoon to stir. It MUST be wet in order to be activated. It will absorb any synthetic drugs if your dog is on any.

      If so, feed them 2 hours apart.

      I hope this helps. You should also get your little one on a good multivitamin like the Daily Multi here Andrew.


  • 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.


  • Michelle

    About 2.5 years ago, the vet ran out of Comfortis. So the vet recommended Triflexis. What a mistake!!!! Our 2 dogs threw up and the 3rd started looking really bad. She was not stable and was stumbling. She started to go down hill and we went to THREE doctors. One said she had heart problems, go see the heart specialist. The next said she doesn’t have anything wrong with her heart but her liver is damaged. We went to the hospital and had her stay overnight.
    They vet tried to squeeze another $2500 and said we should do a liver biopsy. She was perfectly fine before they took this POISON. But she was so weak so we opted to see if she would get better in the next few days even if it just helped to have her get stronger before considering surgery. Luckily she recovered!! Just like human medicine that affects people and there is reporting of severe problems, the medicine is still being recommended by doctors. These drug company’s mislead the vets into recommending this junk medicine. So now we use an organic alternative that kills the fleas in the yard and bypass putting any poison on or in our dogs. Its so sad that we can’t trust a lot of these pharmaceutical companies as profit is before safety. So so sad…

    • janie

      Hi Michelle:

      Thank you so much for sharing your story about Trifexis and your 3 fur kids. How awful. But, I’m glad to hear that she recovered. I’m also extremely happy to hear that you moved away from using these poisons on your dogs.

      Good job Michelle! Your story will definitely help someone else.


  • Dan

    My dog has been sick for 5 days since taking Trifexis. He’s thrown up everything in his stomach since then and has had runny watery stools since then also. Seems obviously to me this drug poisoned my 75 pound dog and I only gave him half a pill hoping he’d keep it down but that didn’t happen. My groomer warned me to not give him Trifexis because it’s killed hundreds of dogs. I’m taking my dog to the vet today before he becomes another statistic.

    • janie

      Hi Dan:

      I’m sorry to h ear about your boy. Trifexis is dangerous and any vet that tells you otherwise should be a good indicator for you to high tail it out of there with your dog as fast as you can.

      Stay away from ALL chemicals including any type of flea and tick products and heartworm medicines Dan.

      I hope all goes well for you and your boy. 🙁


  • Terry

    My husband just informed me that one of our dogs tested for heartworms (early stages.) We were stunned that our dog is infected since he has been taking Trifexis for years. Our vet told us Trifexis was a very good preventable medication. My husband simple ask how could that be since our beloved pet gets his monthly dose, get his yearly examine and vaccinations and instead of answering the question she stated that the medication is good for fleas. So now our dog has to take medication for a month for the heartworms and the vet said we will see him next year…Really! Guess they feel they do not have to follow up on this condition. I’m glad I found this website and there are other more natural remedies that we can treat our pets.

    • yourolddog

      Hi Terry:

      I’m so sorry to hear about your dog. Heartworms are VERY SERIOUS! This page might help. Wormwood and Black Hawhtorn are the two best herbs for fighting heartworm.

      I would love to hear back from you with regards to how your dog does.


  • Kelly Hall

    Janie, in a different article on black walnut you cautioned on using it, but in this article you recommend a product for HW prevention that contains black walnut. What makes this product seem safe to you? I will tell you that in working with Jeff Battershaw to get a rescue HW free, he felt that the itching while using a black walnut product were from detox. Do you find that your dogs itch alot on your recommended product? Thank you!

    • yourolddog

      Hi Kelly:

      You must be referencing my article on using black walnut. I’m not against using it for prevention, but I do recommend that dog owners be careful with it.

      If you’re asking about the heartworm tincture that I recommend in the article, the reason I feel it’s safe is because it is premixed and premeasured Kelly.

      I’ve never experienced the itching while using the heartworm tincture on my own dogs. I’ve also NEVER had a dog diagnosed with heartworm disease either.

      Hope this helps.


  • Rebecca Stanek

    I had been giving her thuja when she got the food poisioning to try to boost her immune system and get rid of the warts that have appeared on her since starting trifexis. When she started eating again I gave her a coupe of the thuja and soon after she got really sick and vomiting again. So I’m scared to give her anymore or the thuja now.

    • janie knetzer

      Hi Rebecca:

      Okay I understand. Lets see how she does with everything else. Keep all fingers and paws crossed. 🙂


  • Rebecca Stanek

    Thank you a million times over for your wisdom and help! I’ve used your links and ordered all 4 products. I will feel so much better when Faith starts using them. Unfortunately last week the vet did give Faith her rabbies update. I don’t know much about the vaccines and what she should and shouldn’t get. I feel terrible that she got the one last week but feel better knowing moving forward she won’t get one. Praying she is off all the meds, chemicals and bad stuff very soon and on her way to feeling tremendously better. Thank you for helping all of us! You are appreciated!

    • janie knetzer

      Hi Rebecca:
      You’re welcome and thank you so much for your very nice comment.

      One other product you might consider(I don’t think I mentioned this to you earlier) is called “thuja” and it’s very cheap. This is very good for reversing any side effects caused by the rabies vaccine. The fact that your girl can’t move after being taken off of the steroids leads me to believe that this would also be helpful.

      Only Natural Pet carries it here. I’m sorry I forgot to mention this earlier Rebecca.

      Please keep me posted and let me know how things go.


  • Rebecca Stanek

    I’ve been complaining to my vet for 2 years that I feel that trifexis is harmful to my dog of which the vet tells me it is completely safe. 3 years ago I moved to a new state and the vets in my area all use trifexis which was new to me. With in a short time of using it my dog seemed to decline in health. This last year have been very difficult for her. After a recent food poisoning incident from “natural” “healthy” dog food I’ve thrown away everything from the store and am making her food myself. She has been a sensitive stomach/picky eater girl but making her food she is not having any issues or protests!

    I found your site researching tummeric as she has been on steriods for several months and tramadol. last year she injured her back and we think had a pinched nerve. She was barely better from that and then I noticed a strange spot on her tummy, it was cancer but was caught extremly early, and was removed. Two weeks after the surgery stiches were out she slipped and pulled her neck and shoulder muscles. Since then when we try to slowly wean her off the steriod within 2 days she is back to being unable to move, her muscles twitch and her body shakes in pain. I just know there is a natural safe approach to be found. We just feel like we’ve experimented with her so much these last several months and are very nervous to try more new things.

    I know lavender oil sprayed on the dog will keep fleas, lice and anything of the kind away but I’m worried about the heartworms. Can you point me in the right direction for safe natural heartworm prevention and any other information/advice you have for me? My sweet girl is between 11-13 years young and an unusal Jack Russell, she doesn’t bark and has been super mellow since I got her from the pound 5 years ago.

    • janie knetzer

      Hi Rebecca:
      Trifexis as far as I’m concerned is one of the worst parasite preventions out there. It’s a buffet of poison that goes through the dog’s bloodstream. Nobody can tell me this is safe. Many dogs die or suffer with seizures, paralysis from flea and tick meds; combine it with poison for heartworm and these poor animals don’t stand a chance.

      I would start with building her immune system immediately. Do this by giving her a good multi-vitamin formula. I like this formula made by Natures Farmacy because not only includes multi vitamins and minerals, but digestive enzymes and probiotics. I would also bombard her with good foods as you already are, but you can use a good brand such as the Honest Kitchen combined with Wellness Ninety Five Percent canned meat. I would also get a good organic 100% natural coconut oil and feed with her food daily (forever).

      With regards to heartworm, here is the natural product that I use Rebecca. The reviews are very good on it and you can read them for yourself.

      I would also stop all chemical flea an tick meds immediately. I use and recommend a product called TripleSure which I’ve been using on my dogs for years. You can learn more about it here.

      Hope this helps you Rebecca. I’m so sorry for your old girl. Don’t allow them to vaccinate her anymore. She has issues and she’s older and should not be vaccinated. Don’t let them bully you into it. Ask for a waiver for the rabies vaccine if they try to push you into it.



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