By Tim McDermott DVM
Ohio is on the forefront for expansion of ticks and tick-vectored disease going from one tick that is medically important to humans, companion animals, and livestock twenty years ago to five ticks now.
Pictured are two adults and thousands of nymphal Asian longhorned ticks collected from a pasture tick drag in a SE Ohio pasture. (Risa Pesapane photo)
I encountered the American Dog Tick way back when I was in clinical veterinary practice, then added the Blacklegged, or Deer Tick in 2010. I talked about the Lone Star tick back in Farm and Dairy on June 27th, 2019 in the article “Don’t Let a Lone Star Tick Bite Make You Allergic to Your Dinner” and still get nervous about potentially getting the mammalian muscle allergy (alpha-gal) that could make me allergic to my favorite food, bacon cheeseburgers.
We finally added two more ticks to get to our total of five in 2020 with expansion to new host ranges of those ticks continuing to this day. The Gulf Coast tick, not a true invasive, has been present in the United States since the 1800’s and was a serious pest for cattle producers at the time assisting with the economic and medical damage caused by the severe and reportable screwworm pest. This tick has established colonies in counties in Southwestern Ohio.
The tick that I mentioned way back in the July 23rd, 2020 edition of Farm and Dairy article “ The Threat of Asian Longhorned Tick Continues” was initially discovered on a rescue dog in southern Ohio in summer of 2020. A second detection of Asian Longhorned tick (ALT) was on a cattle and sheep farm in a neighboring county in the spring of 2021 when the animals were tick-checked while running them through the chute.
There are a lot of unknowns with the Asian Longhorned tick as it is a true invasive. We do not know how far it will spread, and most importantly what diseases it will prove competent to vector, or transmit, to humans, companion animals and livestock.
One characteristic of this tick that causes me major worry is how it can reproduce. This tick species can reproduce via parthenogenesis meaning the female does not need a male in order to lay eggs. That means that one female can establish a colony. This tick was recently found on a Canada goose. Let that sink in . . . if it attaches and feeds on a Canada goose for a week knowing how far they can fly in a day!
The Asian Longhorned tick gave a demonstration of its destructive potential in the summer of 2021. I received an email from a recently retired OSU Extension Agriculture and Natural Resources colleague of mine who grazes cattle in Southeastern Ohio asking me to call him. He told me that when his neighbor did his morning herd check he found three dead cattle. They were covered in ticks in extraordinary numbers. I asked him to get some ticks submitted for identification and my colleague at OSU who first discovered ALT in Ohio, Risa Pesapane, confirmed them as ALT.
A subsequent visit by Risa and her team found the pasture contaminated with large numbers of ticks. The herd tested negative for disease, so the hypothesis is the ticks caused death through blood loss due to exsanguination. It must also be noted the cattle were mature animals, including a bull.
What does the producer need to do to mitigate potential problems from ALT? Make sure to practice good biosecurity and scouting. Check animals carefully for ticks. Manage the area around pastures by clearing brush and keeping weeds short. Work with your veterinarian if you think you have a problem with this tick.
Source : osu.edu