Bovine Theileriosis is Spreading Westward
By Pat Burt – Wild West District Agriculture & Natural Resources Agent
There is a new tick that cattle producers need to be on the lookout for in their animals. The Asian Longhorned tick, while found in many places around the world for a long time, has only been in the eastern United States since around 2010 and has been spreading westward and has now spread to some to parts of Missouri, Arkansas, and Oklahoma. our adjacent states to the east of Kansas. This tick is a problem because it can be a carrier of theileria orientalis Ikeda, which is a blood-borne pathogen that can use cattle as a host, resulting in the transmission of bovine theileriosis to that animal.
Some symptoms of bovine theileriosis include lethargy, weakness, off feed and difficulty breathing, reduced milk production, foamy nasal discharge, abortions and in some cases death. The symptoms may mimic bovine anaplasmosis. Pregnant heifers and young calves appear to be more prone to getting the infection. Currently, there is no approved treatment for bovine theileriosis and once infected, cattle can be lifetime carriers. It should be noted that this disease is not known to be a human pathogen.
Bovine theileriosis is thought to be spread several different ways. Besides the Asian Longhorned tick, which is the primary vector, the disease can also be spread by flies (especially horse flies), transfusions and the practice of re-using needles.
Currently, the Asian Longhorned tick has not been found in Kansas but there has been one case of bovine theileriosis in Kansas in 2024 from calves that were purchased on the east coast and brought to Kansas for feeding. Our dry area of the state is not a very habitable environment for the Asian Longhorned tick so the most likely way the disease would make it out here would be from infected cattle coming into our area.
As always, if you have any health concerns with your livestock, you should consult with your veterinarian. If you have ticks that you need identified, you can bring them by one of our Wild West Extension offices. Do not bring live ticks. Ticks should be placed in a tube with rubbing alcohol.
For more information on Bovine Theileriosis:
USDA Information Sheet:
https://www.aphis.usda.gov/sites/default/files/bovine-theileriosis-infosheet.pdf
K-State Veterinary Diagnostic Laboratory:
https://www.youtube.com/watch?v=9wKiRHhepzs
APHIS Information on the Asian Longhorned tick:
https://www.aphis.usda.gov/livestock-poultry-disease/cattle/ticks/asian-longhorned
