heartworm

American  

[hahrt-wurm] / ˈhɑrtˌwɜrm /

noun

1. a parasitic nematode, Dirofilaria immitis, transmitted by mosquito and invading the heart and pulmonary arteries of dogs, wolves, and foxes throughout its range in tropical, subtropical and, more recently, temperate regions around the world.

2. the disease caused by infection with heartworm.

---

heartworm British  

/ ˈhɑːtˌwɜːm /

noun

1. a parasitic nematode worm, Dirofilaria immitis, that lives in the heart and bloodstream of vertebrates

---

Etymology

Origin of heartworm

First recorded in 1885–90; heart + worm

Example Sentences

Three months and one heartworm treatment later, I carried Bob to the adoption event in Prospect Park.

From Slate • Sep. 4, 2025

The company’s spokesperson, Dan Kramer, said it self reported the heartworm diagnosis and the dog was removed from the donor pool.

From Los Angeles Times • Dec. 17, 2024

Beyond the itchiness, they spread serious diseases and can even transmit heartworm to cats and dogs.

From The Verge • Jun. 3, 2022

A recent Facebook post from the KC Pet Project in Kansas City, Mo., featured a blind elderly pit bull abandoned with heartworm and in poor physical condition.

From Washington Post • Nov. 26, 2021

He was only 10, but he had prostate cancer that metastasized into his lungs, a urinary tract infection and severe arthritis, plus he was heartworm positive.

From Washington Times • May 1, 2017