Asian longhorn tick in Oklahoma remains an emerging concern for cattle producers, and while the pest has only been identified in two Oklahoma counties so far, Oklahoma State University Beef Cattle Extension Specialist Dr. Rosslyn Biggs says producers should understand the risks associated with the tick and the potentially devastating disease it can spread.
Associate Farm Reporter Carli Davenport recently spoke with Dr. Rosslyn Biggs, Associate Professor and Beef Cattle Extension Specialist at Oklahoma State University, about the Asian longhorn tick, where it has been found in Oklahoma, and why producers should be aware of Theileria orientalis genotype Ikeda.
What Makes the Asian Longhorn Tick Different?
According to Biggs, the Asian longhorn tick has one characteristic that sets it apart from many other tick species. “This is a three-host tick, which is a little bit of a difference than some of our others,” Biggs said. “But the one thing that really makes the Asian longhorn tick unique is that they can establish a population of ticks with a single female.”
Unlike many ticks that require both a male and female to reproduce, this species can rapidly establish itself after the arrival of just one female. “The female does not need a male to reproduce,” she explained. “The single female by herself can set up shop, and we can have a population of ticks with just a transfer of a single female.”
Where Has the Tick Been Found?
So far, Oklahoma has seen only limited confirmed detections. “We’ve only identified to this point the tick itself in Craig County and Mays County, and that was in 2024,” Biggs said. “We’ve not to this point seen the tick, or at least identified the tick, in any other counties.”
While the confirmed distribution remains limited, producers are encouraged to remain vigilant as surveillance continues.
Understanding Theileria orientalis Genotype Ikeda
One of the biggest concerns surrounding the Asian longhorn tick is its ability to transmit Theileria orientalis genotype Ikeda, a bloodborne parasite that affects cattle. “Theileria is a bloodborne pathogen—that parasite, if you will,” Biggs said. “Producers are probably really familiar with anaplas. Here’s some differences.”
She explained that several forms of Theileria exist, but the Ikeda genotype is the one causing concern. “We’re particularly concerned about Theileria orientalis, specifically the genotype Ikeda,” Biggs said.
The disease attacks red blood cells, producing symptoms similar to anaplasmosis. “It destroys those red blood cells,” she said. “We can see weakness and jaundice, we can see death, and those death ranges can be highly variable.”
Disease severity can differ dramatically between herds. “In some herds, we may not hardly notice that there are any signs, and in other herds, there have been reports of deaths up to 90% in other states,” Biggs said. “We’ve not necessarily seen that here in Oklahoma as of yet.”
Recognizing the Clinical Signs
Biggs noted one important distinction between Theileria and anaplasmosis is the age of animals affected. “One of the differences between Theileria and anaplas is Theileria can affect all ages of animals and has some affinity for young animals versus anaplas that we typically see in adult cattle.”
Because the disease destroys red blood cells, producers should watch for symptoms associated with anemia. “We can see signs that are consistent with anemia,” she said. “We can see jaundice or yellowing of mucous membranes, for instance. We can see weakness and incoordination, and we can see losses of pregnancies, and even in some cases, as I mentioned, death.”
Prevention Is the Best Defense
Currently, prevention is producers’ primary tool because there are no approved treatment options available in the United States. “That’s the challenge with Theileria,” Biggs said. “Currently here in the U.S. we have no treatment options that are labeled for Theileria, so we’re really left with preventative measures.”
She emphasized that strong biosecurity practices are essential when adding cattle to a herd. “We want to think about our biosecurity,” she said. “We certainly don’t want to unintentionally introduce it to our own herd by making a purchase and not knowing that they were infected or a carrier of Theileria.”
Tick control also remains an important management strategy. “We also want to be thinking about obviously tick and other insect type control that could potentially have transfer of a blood meal, so transfer of the agent,” Biggs said.
She also reminded producers to avoid spreading bloodborne diseases during routine processing. “We don’t want to put a needle in one animal, then use that same needle on another, and inadvertently infect that second animal,” she said. “Biosecurity, certainly cleaning and disinfecting, and using one-use type things when we’re processing cattle is best.”
While Oklahoma has only confirmed the Asian longhorn tick in Craig and Mays counties, Biggs said awareness, biosecurity, and proper cattle management practices remain the best defense against both the invasive tick and the diseases it may carry.
