Heartworm: A deadly, but preventable, disease in pets

BOARDMAN, Ohio (WKBN) -- Mahoning County animal activists are warning about the dangers of heartworm in pets. A dog named Marnie had to be euthanized on Saturday after she was diagnosed with a severe case of heartworm.

According to the American Heartworm Society, the disease is characterized by footlong worms that live in the infected animal's heart, lungs and other blood vessels. It's a blood-borne disease that causes lung disease, heart failure and damage to other organs. The disease can be spread by mosquitos.