Health Scares About Trifexis

December 3, 2013

Dogs across the United States are suffering from bad reactions to the drug, Trifexis, according to a report from Atlanta’s about a dog that died after taking the drug.

Trifexis is a pill taken once a month to prevent heartworm, fleas and other parasites.  Soon after taking this drug for the first time, the little dog developed a 106 degree fever, vertigo, and seizures and the owner was forced to euthanize her beloved pet to end its suffering.

After a bit of investigation, I learned that problems with Trifexis were reported as far back as 2011.  Elanco, the pet products division of pharmaceutical giant Eli Lilly. Believes the drug is safe, stating that 50 mg. doses have been diagnosed since it first came on the market less than 3 years ago.

However, pet owners have filed over 2,000 reports of Trifexis causing pets to vomit.  That would certainly be a red flag to me!  Another concern is that of the 2 drugs contained in Trifexis, one of them, milbemycin is sourced from China.

More research pulled up numerous reports of dogs sickened or killed, reportedly by Trifexis.   I read page after page of complaints  and most wrote of similar symptoms:  Vomiting, seizures, fever, loss of motor control function.

Obvious, if your dog becomes ill with the symptoms listed above, call your veterinarian for assistance.  If you suspect that Trifexis could be the cause, report that to your veterinarian and to Elanco at 800-545-5973.

Veterinarians appear to have mixed reactions about the safety of the drug but if you are the least bit concerned, don’t use it.  It’s that simple.

Because of my Weimaraner’s recent frightening reaction to a popular spot-on flea & tick preventative, I will no longer use that or any medication containing questionable ingredients that could harm my pets.  In the future, we will stick to all-natural products and be more vigilant about examining the dogs when they come inside from a walk.

Keep in mind that Trifexis is a very strong drug.  The label clearly says to watch for side effects.   But most drugs do that, whether for people or pets.  The truth is that there isn’t enough evidence for the Food & Drug Administration (FDA) to demand a recall of Trifexis.  However, there are enough reports of illnesses and deaths to warrant a pet owner being very careful, perhaps switching to a safer option.

Please remember that just because complaints are posted on the Internet, it doesn’t make the information factual.  Talk to your veterinarian about any concerns and use your own judgment.  Only you can decide what is best for your own pet.

Leave a Comment

{ 5 comments… read them below or add one }

Linda February 13, 2014 at 12:56 am

My 5 -6 yo chocolate lab mix 45 lbs has been on Trifexis for about a year with no apparent problems. She was about a 1 yr old rescue when I got her and she got heartworms. They said she probably already had them but was in a stage too early to be detected. She showed no symptoms of heartworms. The vet said that is not that uncommon with rescues and always have them tested 6 months after you get them rather than wait for the yearly physical. She survived the heartworms and seems to be doing fine on the Trifexis so far. She was recently boarded where they let the dogs play together freely. She eats poop and I think she got giardia there. She showed no symptoms but tested positive with her yearly physical shortly after being boarded.


Linda February 13, 2014 at 1:44 am

I am signed up with the FDA to get e-mailed recalls.


rod hewitt September 24, 2014 at 7:56 pm

TRIFEXIS ANTIDOTE—–There is a way to reverse the symptoms caused by Trifexis

It took me three weeks to figure out that trifexis has poisoned my dog.
He is a rare specimen, half jindo and half belgian shepherd he could jump higher
off the ground than Kobe Bryant, he was faster than any cat I have ever seen, a magnificent physical specimen. Then he started to vomit and in the aftermath of three days of that condition
he began to slow down, become letharic and soon has trouble just jumping a foot and a half into the van. He was looking old, his rear end was tender and inflamed. Then I looked at the trifexis package and date and realized the problems traced back to his first dose. I found the fabeook page trifexis kills dogs and realized he was suffering as a result of one dose of trifexis.
I spoke with elanco and they put their head veterinareian on with me. She was quite nice, offered to pay for the vet visit, wanted me to return to the vet who sold me the trifexis. After much discussion she told me there was no antidote for trifexis.

I then contacted a homeopath and she advised me to start a regimen right away,. I started my shepherd on liquid dandelion and liquid milk thistle, fifteen drops apiece, twice a day. As well I gave him one animal strength biosuperfood from bioage, an algae complex that has been remarkable in the past for recovery after illness. After three days the shepherd was bounding again, I slowed the dosage and he reverted to the lethargy and pain. I returned to the previous criteria and after three weeks, he is again strong and vital his regimen has slowed to once a day for the liquids and every three days for the biosuperfood. The tenderness in his rear is gone. I will write and call elanco and inform them or my progress, I suspect that they will continue to maintain an innocence in
regard to the conditions that arise after the use of their produst, but I do believe that the regimen has brought this dog back to his previous most healthy state. I do now believe there is an antidote.


Carol North September 24, 2014 at 9:07 pm

Rod, thanks for writing. So sorry for what your beloved dog has suffered, but I’m glad you found the answer to curing him. Appreciate you sharing the homeopathic antidote. Can you clarify what the biosuperfood from bioage actually is? Is there a brand name and where would I look for that?

Carol North


Carol North December 14, 2014 at 10:07 pm

Thank you for this article. My pups have changed from Comfortis to Trifexis. I’m considering putting them back on Comfortis for the flea problem and go with the regular heartworm treatment after reading this. Love that this is one place I can come to and get serious facts about products we use on our pets. I have full confidence in the information provided. Thank you again.


Previous post:

Next post: