My dog ate Tri-Heart Plus heartworm medicine. Is it safe for her?
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.
Updated on September 23rd, 2025