Researchers test treatments for tick borne cattle disease
A deadly cattle disease called bovine theileriosis is spreading quickly in Arkansas, raising concerns among farmers and researchers. The disease is caused by a parasite known as Theileria orientalis Ikeda and is mainly spread by the invasive Asian longhorned tick.
Cases increased sharply in 2025, only a year after being first confirmed in the state. Ranchers have reported serious herd losses, leading to growing economic challenges across the region.
Researchers from the Arkansas Agricultural Experiment Station, part of the University of Arkansas Division of Agriculture, are now studying two possible treatments. This work is supported by a two-year grant of over $492,000 from the US Department of Agriculture.
The study is led by Emily McDermott, along with collaborators including Kelly Loftin and Jeremy Powell. They are testing an anti-tick vaccine developed by Medgene and a slow-release parasiticide called eprinomectin. This treatment is compared with commonly used tick control products.
Both solutions are already available commercially, which means farmers could adopt them quickly if proven effective.
The disease symptoms often look like anaplasmosis, another tick-borne illness. Affected cattle may show weight loss, reduced milk production, low appetite, anemia, and reproductive problems. However, unlike anaplasmosis, this disease can affect cattle of all ages.
The parasite Ikeda is the more harmful strain and attacks red blood cells, sometimes leading to death. Infection rates can vary, with death losses ranging from 1% to 5%, but in severe cases can reach up to 50%.
The disease has now been confirmed in multiple counties across Arkansas, and cases are expected to grow as infected cattle move between locations. Researchers also believe other insects may spread the disease mechanically through blood contact.
In response, farmers and veterinarians are being trained through outreach programs. These include workshops, field demonstrations, and guidance on preventing disease spread during animal handling.
Experts say this could be one of the most significant tick-borne cattle threats in the US since Texas cattle fever, making early awareness and control efforts critical for the industry.
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