Heartworm is commonly found in dogs and cats. It is a parasitic roundworm which can grow to about six-inches in length and can live in either the heart or arteries of the lungs.
Heartworm is very rarely found in people. An infection occurs after a mosquito bites an infected dog, and then bites a human. While heartworm is serious in dogs and cats, in humans it is not much of an issue and the heartworm usually dies on its own.
Heartworms can live in dogs, cats, ferrets and other smaller mammals for up to 7 years and can cause serious health issues with the potential for death if untreated. Common early signs include coughing, decreased appetite, weight loss and fatigue. Later symptoms can include dark or bloody urine, swollen belly, pale gums, labored breathing and finally heart failure.