By Brian Consiglio
As tick-borne diseases threaten Missouri cattle, the University of Missouri’s College of Veterinary Medicine is leading the charge to protect producers and the state’s livestock economy. At the Veterinary Medical Diagnostic Laboratory (VMDL), experts are providing timely testing services to gain much-needed insights and help researchers and agricultural professionals track the spread of tick-borne diseases across the state.
Rosalie Ierardi and Tirth Uprety, researchers at the VMDL, are monitoring the increase in tick-borne diseases affecting cattle. Below, they offer practical advice to Missouri livestock producers looking to protect their herds.
What are the most common diseases that ticks spread to cattle in Missouri, and have any new threats emerged in recent years?
Ierardi: Bovine anaplasmosis has long been the most common tick-borne disease impacting Missouri cattle, and the American dog tick carries the bacterium Anaplasma marginale, which causes it. A 2025 Mizzou study found that nearly half of all Missouri cattle have been exposed to the disease. The economic consequences can be devastating for producers, as the disease kills red blood cells in cattle, causing lethargy, weight loss and sometimes pregnancy loss or death.
In recent years, bovine theileriosis has emerged as another tick-borne disease affecting many Missouri cattle. Bovine theileriosis is spread by the invasive Asian longhorned tick, which carries the Theileria orientalis parasite. This tick was first identified in Missouri in 2021, and researchers have since documented it in additional counties across the state. As the tick expands its range, livestock producers are increasingly concerned about the economic consequences. Similar to bovine anaplasmosis, bovine theileriosis kills red blood cells in cattle, causing weight loss and potentially pregnancy loss.
Source : missouri.edu