Last week, on June 10, a herd of cattle in central Tennessee was reported to have Theileria orientalis Ikedia, a protozoan disease vectored by the invasive Asian longhorned tick. This protozoon attacks red and white blood cells and causes bovine infectious anemia, lethargy, weakness, and possibly death in up to 5% of infected cattle. Cattle that recover can become carriers for the life of the animal. There is currently no vaccine or treatment for T. orientalis.
The Asian longhorned tick is a carrier (vector) of Theileria orientalis. To date only seven Kentucky counties (Boone, Breathitt, Floyd, Martin, Metcalfe, Madison, and Perry) have had confirmed Asian longhorned tick samples, but it is likely that other Kentucky counties may have introductions of this invasive tick as it continues to spread. Currently, the strategy is to monitor herds, regularly inspect for ticks, and manage ticks as necessary. Once Asian longhorned tick is confirmed in an area, management for this tick will be a continuing process focused on habitat management and on animal treatments.
Fortunately, this bovine disease is not a threat to human health. Humans cannot become sick from contact with infected animals or from consuming meat from affected animals, provided that the meat has been cooked to the appropriate temperature.
Cattle producers can help to minimize Asian longhorned tick exposure risk by keeping cattle out of wooded areas, mowing pastures regularly (particularly those near wooded areas), and cutting down on brush accumulation. Ticks don’t like to be exposed to the sun, so tall grass and brush favors tick survival. Regular tick checks of cattle can also help to intercept Asian longhorned tick and possibly curtail spread of this pathogen. When inspecting cattle for ticks, check on the head and neck, flanks and back, armpits, groin, and under the tail.
More information on this report from Tennessee and specific recommendations for cattle producers can be found in the news release from the University of Tennessee Institute of Agriculture.
By Ric Bessin and Jonathan Larson, Entomology Extension Specialists