Do You Know What's Crawling On Your Cattle?

The Asian longhorned tick spreads theileriosis, a disease caused by a parasite that feeds off cattle’s red and white blood cells.

- By Courtney Love

Eastern Virginia cattle producer Steve Hopkins knows his 300 Angus and SimAngus cows will encounter a pest or two while out on their lush summer pastures. But in 2018 the pests his cows were hosting were worse than he could have imagined.

That year, Riverview Farms Cattle lost seven cows. A year later, the farm lost two out of 22 bred cows Hopkins had recently purchased.

At first, Hopkins suspected it was anaplasmosis, a common tick-borne disease. But when he treated the cattle for it, they didn’t respond to the antibiotics. A call to his veterinarian and one blood test later, Hopkins would learn that 95% of his herd was infected with Theileria orientalis Ikeda, which causes theileriosis.

“Once you have the first wave, it gets better. All those that made it through are now resistant,” Hopkins says.

A Deadly Pest

Theileriosis is a disease caused by a blood-borne parasite that feeds off cattle’s red and white blood cells. The disease is spread by the Asian longhorned tick, an invasive species from northeast Asia. USDA discovered the tick in 2017 on sheep in New Jersey.

Since then, the tick has spread to 17 states: Arkansas, Connecticut, Delaware, Georgia, Kentucky, Maryland, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, and West Virginia. In 2022, the tick was on two breeding bulls that fell ill and died in Kentucky, according to the state’s department of agriculture. The University of Missouri also found the tick in a pasture in Linn County, Missouri.

“This is troubling because this tick is spreading quickly and efficiently throughout the United States,” says Lindsay Fry, a USDA veterinary medical officer.

Unlike the common deer and cattle fever ticks, Asian longhorned females are parthenogenetic, which means a female doesn’t need a male to reproduce.