Heartworms are a type of parasitic organism that lives inside the heart and lung arteries of cats and dogs and grows by feeding on the surrounding blood. It’s an easily preventable, yet very costly and difficult disease to treat. In some severe cases, the parasite can grow to around 30cm long and around 2cm thick, with a population of more than 200 individuals. Heartworms offspring are also known as Microfilariae and can be found throughout the infected pet’s blood. How does it spread? Heartworm