5. Address the envelope. In the lower right third of the envelope, write the name of the person you are sending the letter to. Write the company name on the line below that (if there is a company name).
Once inside a new 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 dogs and up to 2 or 3 years in cats. Because of the longevity of these worms, each mosquito season can lead to an increasing number of worms in an infected pet.
As an adult, the heartworm is able to breed with other heartworms and produce microfilaria. These tiny microfilaria are picked up by blood-sucking mosquitoes and carried to other pets where the process begins again. Key facts about heartworm disease in dogs and cats. Heartworms are carried by mosquitoes.