Heartworm is a common disease in dogs and cats in all areas throughout the world. A heartworm infection in your dog can be a very serious health problem but can be prevented with an effective dog heartworm medicine. The disease is caused by the roundworm Dirofilaria immitis. Dog, cats, foxes and raccoons are infected with the worm through the bite of a mosquito carrying the larvae of the worm. The best way to deal with dog heartworm is to prevent the dog from becoming infected. We have listed the top Heartworm medicine such as Heartgard Plus, Revolution, Tri Heart Plus, Sentinel Flavor Tabs, Advantage Multi, Iverhart Max and Interceptor Heartworm. Heartworm in your large breed dog can be a serious health concern but can be prevented with the proper heartworm medication.