18 NEBRASKA CATTLEMAN June/July 2026 Nebraska Cattle Health Update Bovine Theileriosis and the Asian Longhorned Tick MATT HILLE, DVM, NVDC VETERINARY PATHOLOGIST AND NEBRASKA EXTENSION SPECIALIST | J. DUSTIN LOY, DVM, NVDC DIRECTOR AND VETERINARY MICROBIOLOGIST | DUAN LOY, PH.D., NVDC VETERINARY MICROBIOLOGIST | ROBERTO CORTIÑAS, DVM, SVMBS VETERINARY PARASITOLOGIST The Vector The Asian longhorned tick (ALHT) (Haemaphysalis longicornis) is native to the Eastern Hemisphere and was first detected in the United States at a port of entry in New Jersey in November 2017. Detections have since spread west across numerous states with recent detections reported in the surrounding states of Iowa, Kansas and Missouri. Adult ticks can be physically transported to new areas; however, establishment of populations require specific environmental conditions that include amenable climate, vegetation and humidity. Therefore, detection of a small number of ticks does not necessarily indicate an established tick population. It’s unclear whether portions of Nebraska would be suitable for ALHT populations to become established. In 2018, researchers published a report in Nature that modeled where tick-suitable environmental conditions exist throughout the United States to predict the potential spatial distribution of the ALHT. ALHT detections since then fit well with the study’s predicted spatial distribution over time. Note that of the three models developed, two models predict portions of both western and eastern Nebraska as being suitable for ALHT establishment. Two other groups have done similar modeling studies and do not include Nebraska as a suitable location for ALHT distribution. As of April 2026, there have been no confirmed detections of ALHT within the state. Tick Identification ALHT are roughly 2 mm in size (similar to a sesame or mustard seed) prior to a blood meal and light brown to burnt orange in color. If ALHT is suspected, the Nebraska Veterinary Diagnostic Center (NVDC) offers preliminary tick identification. For accurate tick identification, proper tick removal, storage and transport is important. • Ticks should be removed by grasping them at the base of the mouthparts, as close to the skin of the host as possible. Slowly and forcefully pull the tick away from and perpendicularly to the skin to prevent tearing of the mouthparts. Mouthparts are typically important for tick identification. • Ticks should be placed in sealable containers (e.g., glass vials, plastic vials) with alcohol, preferably 70 to 90 percent ethanol. Areas predicted to be suitable for establishment of the Asian longhorned tick in North America. Female adult Asian longhorned tick. Photo credit: USDA APHIS via James Gathany, CDC. PRODUCTION
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