April is “National Heartworm Awareness” month. Heartworm disease is a severe and potentially fatal disease caused by foot-long worms that live in the heart, lungs and associated blood vessels of affected dogs. It causes severe lung disease, heart failure and damage to other organs in the body. Mosquitoes spread the disease. When a mosquito bites an infected animal, it picks up baby worms, which develop and mature into “infective stage” larvae over a period of 10-14 days. Then when the mosquito bites another dog, the infected larvae are deposited onto the surface of the animals skin and enter the new host through the mosquitoes bite wound. Once inside the host, it takes approximately 6 months for the larvae to mature into adult heartworms. Once mature, heartworms can live for 5 to 7 years. In the early stages of the disease, many dogs show few symptoms or no symptoms at all. Initial Signs of heartworm disease may include mild persistent cough, inactivity, fatigue, loss of appetite and weight loss. As the disease progresses, dogs may develop heart failure and fluid buildup in the abdomen. If there are great numbers of heartworms present a sudden blockage of blood flow to the heart can develop. Heartworm disease causes lasting damage and can affect a dog’s health and quality of life long after the parasites are gone. That is why prevention is the best option.