|Heartgard Plus contains small amounts of two different medications. These medications are meant to kill off heartworms and some small intestinal parasites as a means of prevention. If your dog is taking the medication regularly, any worms that do get into its system will be killed by the small dosage. Heartgard for dogs isn't meant to get rid of a widespread problem, which is why veterinarians test for the worms before administering the medication.
||The main purpose of giving your dog this medication is to prevent the development of a heartworm infestation. These worms get into your dog's blood primarily through mosquito bites. In addition to giving your pet the prescribed amount of Heartgard Plus, protecting your pet from these insects can also decrease the chances of a heartworm infestation. This medication has also been proven to treat and prevent widespread infestation of intestinal parasites, such as hookworms and roundworms.