Warning: DO NOT mix Trifexis with Ivermectin

Last night, we rushed Loki to the dog emergency clinic late at night. The incident occurred like this:

Around 8pm, I got home from work and found Loki resting by my boyfriend’s side (who slept for the past 8 hours). There was drool all over his pillow and he refused to get up (which is unusual). I picked him up and set him on the ground, only to realize that something was really wrong.

– head bobbing
– fast heart rate
– drooling
– weak hind legs, keeps falling down
– unable to walk straight, tail down

As usual, here is a video to show you some of his symptoms. The symptoms I captured on film improved since I discovered his illness, so I wasn’t able to capture the ‘weak hind legs’ part (it is really obvious when you see it though).

A similar incident occurred back when we first got Loki as a puppy. This was when Loki was 5-6months old, and the doctor concluded “he ate too much or something poisonous” after running blood tests and xrays. The cure? Saline injection to keep him hydrated and his bowels moving.

Yesterday at 12:30pm, I reminded my boyfriend to give Loki his monthly dosage of flea medication (Trifexis). Nothing unusual there. Two weeks ago, we noticed Loki had an unusual bald spot around his right eye. A trip to the vet confirmed that he had demodectic mange, and the vet prescribed him a daily dosage of Ivermectin. So in addition to the Trifexis, we also gave his his daily dosage of Ivermectin 0.73cc by mouth. We should have known better. It was a mistake on our part for forgetting to ask about mixing medications. It was a mistake on the vet’s part for not asking about his medication history, or giving us any warning about mixing medications. It was just…bad.

mangeBeginning symptoms of mange: redness and baldness around his right (left in this picture) eye.

Its hard to say when the symptoms started occurring, especially since my boyfriend slept right after he gave Loki both medications. Based on the amount of drool on the pillow however, it looks like he was suffering for a while 😦

A quick google on the internet showed that the cause was likely mixing Trifexis with Ivermectin. If you suspect that your dog ingested something poisonous, call the animal poison control immediately. The vet will diagnose your problem and give recommendations for next steps, and the call is $65. After the call, poison control recommended that we take Loki to the emergency vet to check his vital signs.

When we arrived at the emergency vet, they assessed Loki’s vital signs and concluded it was within normal range. Examination findings include:

Temperature: 102F
Pulse: 130BPM
Respiratory rate: 60BPM
Weight: 26.7lbs
Cardiovascular: no murmurs. Good pulse.
Abdomen: Non painful. No overt masses
Lymph nodes: within normal limits
Nervous: Cranial nerves normal
Mild head bob.

After his exam, the emergency vet came in and presented us with her recommendation. She wanted us to follow poison control’s recommendation – to leave Loki overnight to monitor his sodium level and run more blood tests. You know where this is headed right? $$$$$$$$$. If you have a dog, then you probably understand how expensive trips to the vet can cost. I don’t have dog health insurance because I set aside money every month for emergencies, and overall the cons seem to outweigh the pros. Anyone have recommendations? This was the initial estimate for his overnight stay:


Blood tests. Sodium monitoring. Liquid injection. Activated charcoal. Lab work. Blah blah. On the low-end, at least $600. On the high-end, $1000. Before going to the vet, I had mentally prepared myself to shell out $500-$1000 for this vet visit. My boyfriend, a nurse at a busy medical hospital, thought otherwise. He was irritated that the vet neglected to give us options to choose from. When the vet came in, she said “We need to do this. And have him stay overnight. Its what poison control recommends.” To me, it was very straight forward. To my boyfriend, it was irritating that the vet did not discuss options and the pros/cons of each option.

When the vet technician came in with the $600-$1000 estimate, my boyfriend asked about taking Loki back home to monitor his progress instead. I’m not recommending that you do the same thing, but for our situation, it was based on the fact that:

1) His vital signs are normal
2) His illness had slightly improved since we first discovered
3) Boyfriend could stay up all night to monitor his progress. If needed, we could take him back to the ER

The technician had a quick chat with the vet, and came to the conclusion that yes, we could have this option. The result?

estimate2Taking him back home would cost $283. That is a HUGE difference. If we didn’t ask for an option, we would have paid 3x-4x as much.

I’m not entirely sure how effective giving him activated charcoal is. Given that we took him to the vet 9 hours after ingestion, would charcoal even absorb any of the medication circulating around the body? In any case, when Loki got home, he gulped 2 bowls of water and threw up a mess of black, charcoal’y liquid. 

As I’m writing this blog post now (the morning after), Loki’s condition looks much better. He isn’t wobbling or head bobbing anymore, and hes able to walk without falling over. We took him to his regular vet, and the vet said he appears to be doing well. Take him off ivermectin for 3 weeks, and start using it again until his skin clears up from mange. As for the flea treatment, she recommends getting off Trifexis (because of the adverse reaction) and using a topical treatment instead. And so we now have a package of Activyl.

Total cost of ER scare: ~$478
poison control hotline: $65
ER visit: $283
Vet checkup next day: $130

Let this be a lesson learned. ALWAYS double check with your vet on medication incompatibilities.


2 thoughts on “Warning: DO NOT mix Trifexis with Ivermectin

  1. Michelle

    We had a similar experience at the animal ER. Not a medication problem, but our pup got into some gum and after inducing vomiting the vets wanted to
    Keep her overnight for monitering at about $1000. They presented it very matter of fact, this is what she needs. After crying about the bill for 10 minutes I asked them do we have any other options? Can u tell us what signs to look out for and we will stay up all night and monitor her at home? Oh yea, of course but they don’t tell you unless you ask, that you have options. I am learning more and more to question everything the vet says, but even so they won’t really tell you. They tell you their recommendation for treatment and you really have to do the research to figure out what is actually necessary because they just want the $$$.

  2. carol

    I’m trying to find out if I need to skip a month treatment for heartworm prevention at the beginning of the month I gave triflexis but want to switch to ivermectin in September. Dies anyone know what the amount of time id safe to switch to ivermectin from tri flexis?


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s