The larvae penetrate the dog's skin and migrate through the tissues and develop over the next few months, eventually reaching the dog's heart. Once in the dog's heart, the worms can grow to as long as 14 inches and cause significant damage to the heart, lungs and other vital organs. If left untreated, heartworm disease can result in death. Dogs can be tested for heartworms easily and prevention is as easy as giving the dog an enjoyable treat once a month. Treatment can consist of lengthy hospitalization, placement of an intravenous catheter, along with the delivery of very potent medications-often at high cost.
Some animals can experience serious side effects to the treatment-even death.