As a subject matter expert in veterinary medicine, I can explain how Heartgard Plus operates to protect dogs from heartworm disease and other parasites. Heartgard Plus is a monthly oral preventative treatment for dogs that contains two active ingredients: ivermectin and pyrantel pamoate. Here's how each component functions: 1. Ivermectin: This medication is effective against heartworm larvae. When a dog is bitten by a mosquito carrying heartworm larvae, these larvae enter the dog's body and begin to develop. Ivermectin works by killing the larvae within the first 30 days after infection. By eliminating the larvae, it prevents them from maturing into adult heartworms, which can cause severe health issues in dogs. 2. Pyrantel pamoate: In addition to its heartworm preventative properties, Heartgard Plus also contains pyrantel pamoate, which is an anthelmintic that targets and eliminates certain gastrointestinal roundworms and hookworms in dogs. This dual action makes Heartgard Plus a comprehensive deworming and heartworm prevention treatment. When administered monthly, Heartgard Plus provides a simple and effective means of protecting dogs from heartworm disease and treating certain gastrointestinal worms. It's important to follow the dosage instructions provided by a veterinarian to ensure the medication is effective and safe for the animal. read more >>

It contains 2 medications: ivermectin and pyrantel pamoate. Ivermectin prevents heartworm disease by killing heartworm larvae that have infected your dog during the previous 30 days. By killing the larvae, HEARTGARD Plus stops larvae from developing into juvenile and adult heartworms, thereby preventing the disease.read more >>