Here's why:
* Toxicity: Heartworm pills are designed for dogs of specific weights, and a large pill meant for a larger dog can be toxic to a smaller dog.
* Potential for Complications: Ingesting a pill that's not meant for your dog's size could cause digestive issues, vomiting, diarrhea, or other problems.
* Emergency Care: Your veterinarian can assess the situation and provide the best course of action.
Please don't hesitate to reach out to your vet. It's always better to be safe than sorry.