One of the most worrisome things about ticks in Ohio has been the increasing number of ticks that are medically important to humans, companion animals and livestock. We have gone from one tick of medical importance 20 years ago to five now, including two new ticks in the past few years.
While ticks have always been a problem in cattle, the invasive Asian long-horned tick — first discovered in Ohio in 2020 — has demonstrated the ability to not only vector, or transmit disease to cattle, but to cause mortality in cattle through a high number of ticks feeding upon the animals.
I first wrote about the Asian long-horned tick in All About Grazing in July 2020 with the article “The Threat of Asian long-horned tick continues.” I then followed up with a March 2, 2023 article, “Managing Asian long-horned ticks on pasture,” to provide an update on where we were in Ohio with the Asian long-horned tick.
Where are we seeing the Asian long-horned tick in Ohio right now?
At the end of 2023, we had positively identified it in 11 counties in Ohio, including Franklin, Delaware, Ross, Gallia, Vinton, Jackson, Athens, Morgan, Monroe, Belmont, and Guernsey counties. We anticipate finding more positive counties in 2024 as this tick likes to feed on many different species of wildlife and, therefore, can move on wildlife while feeding over a seven to 10-day period.
When should I start scouting for the Asian long-horned tick?
While you can encounter a tick any month of the year in Ohio — and we have had positive cases of Lyme disease diagnosed in every month of the year in Ohio — Asian long-horned ticks prefer more heat and humidity than most native Ohio tick species.
Having said that, in 2023, we detected the Asian long-horned tick on a farm in Gallia County in April. Our Ohio weather can be pretty variable. The producer reported 80 degrees in the two weeks prior, so the ticks emerged from overwintering to feed.
The largest numbers of the Asian long-horned tick on cattle have been in July, but we know that the weather can play a factor in emergence. To learn more about the Asian long-horned tick, check out the new Bite Site: go.osu.edu/BITE.
Have we found Theileria in cattle in Ohio?
Yes, we have had positive diagnoses, through Ohio’s Animal Disease and Diagnostic Laboratory and Virginia’s ViTALs laboratory of Theileria orientalis IKEDA, in eight counties including Crawford, Guernsey, Adams, Columbiana, Tuscarawas, Monroe, Belmont, and Harrison counties.
The first case of Theileria in Ohio was found in September 2022. Theileria can cause increased heart rates and respiratory rates, anemia, jaundice, open cows, and increased mortality. There is no approved treatment, except supportive, approved in the United States.
There is a test your veterinarian can use to diagnose Theileria in a suspected case. If you have medical concerns regarding ticks and Theileria in cattle, make sure you have a valid veterinarian-client-patient relationship in place so you can get the best medical guidance from your vet to keep your animals safe.
I have been collaborating with colleagues at The Ohio State University College of Food, Agricultural, and Environmental Sciences, College of Veterinary Medicine, and the Knowledge Exchange to create a website with information on biting arthropods and the diseases they can vector over the past year or two.
The Bite Site will have up-to-date information on the newest research and data to assist Ohio producers in keeping themselves, their families, and their animals tick-safe.