By Rosslyn Biggs, DVM, Oklahoma State University Extension

The Asian longhorned tick (ALT), Haemaphysalis longicornis, an invasive species has been making its way across the nation. In the summer of 2024, it was discovered on cattle in northeast Oklahoma counties.

The ALT parasitizes multiple species including humans, pets, livestock and wildlife, including birds. It is a three-host tick that spends 90% of its life off the animal. The four most common animals this tick has been found on within the United States are dogs, white-tailed deer, raccoons and cattle. 

A single female tick can reproduce without mating and may produce 1,000 to 2,000 eggs at a time. It has the potential to create an established population in a newly introduced location in two to three weeks.

Severe infestations of the ALT in cattle can lead to death from excessive blood loss. Production losses including decreased milk production and growth are substantial. The Asian longhorned tick has also been recognized as a vector for multiple diseases of both humans and animals.

In other countries, the tick is the primary vector of Theileria orientalis Ikeda genotype in cattle.  The protozoal agent causes clinical signs similar to anaplasmosis-anemia, fever, lethargy, jaundice and death. The mortality rate for cattle infected with T. orientalis Ikeda genotype varies from three to 90%. T. orientalis Ikeda genotype has been identified in the United States, but as of this time not in Oklahoma.

Beginning in late 2024, Oklahoma State University College of Veterinary Medicine researchers will launch a project to evaluate the status of the pathogenic T. orientalis genotype Ikeda and the Asian longhorned tick in cattle herds from Oklahoma and eastern border states. Thirty to 50 farms have the opportunity to participate.

Each participating herd will provide five to twenty blood samples. Herds that test positive to T. orientalis will be followed up with once or twice during the study. Ticks will also be collected from the animals. Tick trapping may also be performed. A maximum of 15 ticks will be analyzed from each sample collection site. All samples will be tested at the Oklahoma Animal Disease Diagnostic Laboratory.

Sampling supplies, shipping labels, and testing will be provided at no cost. Samples may be collected by veterinarians or producers with a consulting herd veterinarian. Anaplasma marginale testing will also be provided free of charge (up to 20 samples per herd) if anaplasmosis is suspected in the herd.

For more information or to participate in the study, please contact a member of the research team: Dr. Ruth Scimeca [email protected], Dr. Rosslyn Biggs [email protected], or Dr. John Gilliam [email protected].