I’ve included for you a memo from the New Jersey Department of Agriculture regarding Theileria orientalis subtype Ikeda found in NJ.
Theileria orientalis Ikeda is a tickborne protozoan infection in cattle (but can impact sheep and goats) that is most commonly spread through the bite of an ixodid tick. An emerging vector for this disease is the Asian longhorned tick (Haemaphysalis longicornis), a tick that was first identified in Hunterdon County in 2017 and has since been detected in 21 states and DC. This tick is active in New Jersey from March through October or early November (Ticks Don’t Take a Winter Vacation).
Well, what will happen if animals get bitten by an infected tick?
- The T. orientalis Ikeda protozoa will infect the red and white blood cells, which results in anemia in affected animals.
- Due to anemia, infected cattle may appear similar to those affected by anaplasmosis.
- Common clinical signs include weakness, inappetence, pyrexia (elevated body temperature), mucosal pallor (pale gums/mucus membranes), jaundice, and elevated respiratory and heart rates.
T. orientalis Ikeda infections have been reported to cause mortality in 1- 5% of infected cattle but can be as high as 50%. Pregnant heifers and calves are particularly susceptible to infection. While there are several types of T. orientalis found in the United States, to date, only T. orientalis genotype Ikeda has been shown to cause severe illness in animals.
How do you control it?
- There is no approved treatment or vaccine for T. orientalis in cattle in the United States.
- The best method of prevention is tick control. Recommended strategies include:
- Veterinary-approved pesticide treatment (such as pour-on and ear tags)
- Regular tick inspections
- Clearing of bushes
- Keeping pastures and grass mowed short.
A useful document can be found here: Managing the Asian Longhorned Tick: Checklist for Best Management Practices for Cattle Producers
The NJDA Animal Health Diagnostic Laboratory (AHDL) is currently working to coordinate diagnostic testing for T. orientalis. For further information on testing, veterinarians should contact the laboratory at (609) 406-6999 or via email at jerseyvetlab@ag.nj.gov. As an emerging disease in New Jersey, knowing detected cases of T. orientalis can help determine the impact of this disease on New Jersey cattle.
