heartworm

noun

heart·​worm ˈhärt-ˌwərm 

: a filarial worm (Dirofilaria immitis) that is a parasite especially in the right heart of dogs and is transmitted by mosquitoes

also : infestation or disease caused by the heartworm

Examples of heartworm in a Sentence

Recent Examples on the Web

Both species must be considered healthy, be up to date on certain vaccines like rabies and distemper, and take year-round flea, tick and heartworm preventive medication. —Jen Reeder, Forbes.com, 9 July 2025

He's neutered, heartworm negative, and ready to go home for an adoption fee of $100. —Alice Gibbs, MSNBC Newsweek, 28 June 2025

This could lead to heartworm and even serious diseases like West Nile virus and eastern equine encephalitis in our furry friends. —Brandi D. Addison, Austin American Statesman, 10 June 2025

MetLife’s preventative care plan includes vaccines, spaying/neutering and heartworm prevention, behavioral training and up to $150 toward teeth cleaning, among other benefits Standout benefits: Claims can be filed online and reimbursed within 10 days. —Liz Knueven, CNBC, 30 Dec. 2024

Word History

First Known Use

1877, in the meaning defined above

Rhymes for heartworm

• affirm
• bookworm
• confirm
• cutworm
• earthworm
• infirm
• midterm
• tapeworm
• wireworm
• angiosperm
• echinoderm
• berm

Medical Definition

heartworm

noun

heart·​worm -ˌwərm 

1

: a filarial worm of the genus Dirofilaria (D. immitis) that is especially common in warm regions, lives as an adult in the right heart especially of dogs, and discharges active larvae into the circulating blood whence they may be picked up by mosquitoes and transmitted to other hosts and that may infect humans causing local pulmonary infarction but does not achieve sexual maturity in the human organism

2

: infestation with or disease especially of dogs caused by the heartworm, resulting typically in gasping, coughing, and nervous disorder, and when severe commonly leading to death