Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

My dog ate Tri-Heart Plus heartworm medicine. Is it safe for her?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed | Female | spayed | 1 year and 1 month old

My 13mo old 10 lb. shorkie just ate 6 tablets of Tri-Heart Plus for dogs up to 25 lbs.I haven't been able to locate a vet that is open this time of n.

4 Answers

Most Helpful Answer

Image profile

Answered By Dr. Melanie, BVSc MS

Veterinarian

Published on June 23rd, 2016

You did exactly the right thing by calling around to vets to ask for help right away. It's always best to check when you aren't sure, and are worried about your pet. The Triheart dose that we give dogs for heart worms has very small doses of the two medications that are in it. Ivermectin is one of the medications that is in the Tri heart. The dose is 68 micrograms. Veterinarians use this medication also to treat dogs with skin mites and use a dose over 100 times the dose in one heart worm preventive tablet. Therefore, even if she would have eaten two or three boxes of the Triheart she should be very safe and there is not any risk of an overdose of the ivermectin. The other medication is called pyrantel pamoate which is used for deworming of intestinal parasites. This medication has a very large safety margin also, and can be given at 10-20 times the normal dose without any risks of toxicity. Therefore, just like with the ivermectin in the Triheart Plus, I would not expect any potential side effects either. These potential side effects could include an upset stomach, mild diarrhea, and/or vomiting. Monitor her for those side effects, and bring her into your vet in the morning if you are still concerned.

Vote icon

51Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By Andrea M. Brodie, DVM

    Veterinarian

    Published on

    The TriHeart dose that vets give dogs for heart worms contains a very low dose of Ivermectin and pyrantel pamoate and at the dose your dog ate the TriHeart, there is extremely little chance that she will get overdosed. Both medications have a very large safety margin and I would not expect any potential side effects Since she ate a large amount of chews she may get an upset stomach, although this is unlikely also. Watch for mild diarrhea or vomiting, just in case.

    Vote icon

    30Pet Parents found this answer helpful

  • Image profile

    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on April 17th, 2019

    No need to be concerned! Heartgard is a very safe medication, and toxicity is only seen if the dog is given an excessive amount of the medication, like 10-20 times the recommended amount. Barry Allen will be fine.

    Vote icon

    1Pet Parents found this answer helpful

  • Image profile

    Answered By David Elbeze, DVM, MRCVS

    Veterinarian

    Published on December 8th, 2016

    The amount of Ivermectin, which is the potentially toxic ingredient, is still very low in those tablets, you should not see any signs of toxicity even after the ingestion of a double dose. Just in case, here are the signs you should be aware of, if you see any of those you should take him to the vet right away: depression, ataxia, tremors, drooling, paresis, recumbency, excitability, stupor, coma

    Vote icon

    2Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
What fish dog food helps dry skin if my dog eats Science Diet?
Is your dog's dry skin a concern? A certified vet offers expert advice on finding the best fish-based dog food alternatives to Science Diet for essential oils.
Updated on February 04, 2026
Petco Pet Education Center
Food & Nutrition
What's the best way to feed my hamster when I'm going on a trip?
Planning a trip to Chicago and need to feed your Syrian hamster? A certified vet offers expert advice on feeding options for short and long trips, plus finding trusted pet sitters.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
Can chickens eat bell peppers daily and what about veggie salads?
Can your chickens eat bell peppers and salads? Veterinarian Dr. Elizabeth offers expert advice on safe feeding, frequency, and how fresh veggies boost vibrant yolks.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
My newly adopted pet won't eat hay. What can I do to encourage it?
Adopted a pet not eating hay? Dr. Stafford, a certified vet, offers expert guidance on encouraging hay consumption, including adjusting pellets and trying fresh types.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My pet is breathing hard, not eating, and lethargic. What's wrong?
Is your rat breathing heavily, won't eat, and has no energy? A Licensed Vet Tech explains potential causes like infection and age, urging a vet visit for diagnosis.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My degu lost teeth after an accident. How can I feed him soft foods?
Your degu had an accident, lost teeth, and can't eat hard food. A Petco Vet Tech offers crucial advice on immediate vet care and how to feed your injured degu.
Updated on December 04, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored