Non-native ticks impact cattle herds

DUBUQUE, Iowa — Introduction of non-native tick species like the Asian longhorned tick can have significant impacts on cattle herds.

“It is just a matter of time before the Asian longhorned tick will be throughout most of the United States, and once the tick is there, theileriosis always follows no matter what country or state we are talking about,” said Teresa Steckler, University of Illinois Extension specialist, commercial agriculture.

Non-native ticks are not just a problem in the U.S., but also internationally, Steckler said during a presentation at the Driftless Region Beef Conference in Dubuque, Iowa, hosted by the University of Illinois Extension, Iowa State University Extension and Outreach and University of Wisconsin-Madison Extension.

“In Australia, they have the Bush tick and the Theileria infection came with it,” the speaker said. “There are numerous hosts for the Bush tick and cattle seem to be the preferred host, but they will also infect sheep and pigs.”

Tick-borne diseases are on the rise with the changing dynamic occurring in the environment. “Weather plays an important part,” the Extension specialist said. “And people are moving into new areas that had traditionally been non-inhabited, like woods.”

The first Asian longhorned tick was found in the U.S. in 2017. “A lot of these ticks are very similar so they can easily be overlooked or misidentified,” Steckler said.

“That is what happened with this tick, they went back in the archives and that’s where they found this tick was in a deer sample from Kentucky in 2010,” the speaker explained.

The Asian Longhorned tick is reddish brown in color and smaller than most other ticks. “When unfed they are 3 to 4 millimeters in length and when they are fully engorged, they are 8 to 10 millimeters in length or about the size of a pea,” the Extension specialist said.

This tick is a three-host species. “It must complete its life cycle by biting three different hosts,” the speaker noted.

“When it is a larva, it will seek out a smaller host, maybe a mouse or raccoon, it takes a blood meal, drops on the ground, molts and looks for another animal to take a blood meal, drops off and molts,” Steckler said. “When it becomes an adult, it can be on a host of animals, take a blood meal, drop off and lay up to 2,000 eggs.”

The key to this tick, the speaker said, is that it does not need a male to reproduce.

“The tick does not care what it bites, there are a host of animals it will latch onto including dogs, deer, bear and migratory birds like Canada geese,” she said. “That is an easy mechanism for the tick to move from one place to another.”

Ticks like low-lying swampy areas, wooded areas and they prefer taller grasses, Steckler said. “That’s why we recommend guys take one pass with a mower around the perimeter of the pasture to try to create a buffer between the wooded or swampy areas and where they want the cattle to graze,” she added.

Asian longhorned ticks will be found on the ears, groin and vaginal areas of cattle and the brisket area as well. “It only takes one tick to turn into hundreds of thousands of ticks on your farm in no time,” the speaker stated.

“Generally, for well-managed herds we don’t have a problem with the Asian longhorned tick,” Steckler said. “But you really have to watch for this tick; you can’t turn your cattle into a pasture and walk away for a month.”

A little different cattle management will be required depending on how close the herd is to where ticks have been reported. “If you are within one county of ticks being reported, you should probably observe your cattle on a weekly basis to make sure you don’t see large infestations of ticks,” the speaker advised.

“But even if you do not see large infestations, that does not mean the ticks are not there. The problem is the tick will transmit theileria through your herd,” Steckler stated.

Theileriosis presents just like anaplasmosis. “Theileria causes infectious bovine anemia, so the cow becomes anemic, she goes off feed and becomes listless,” the speaker explained. “You will not know the difference between theileriosis and anaplasmosis until you get a blood test done.

“This will go through your herd so fast, you probably won’t notice, except for a cow in the late stage of pregnancy you might see an aborted fetus or she may reabsorb the fetus depending on the stage of pregnancy,” Steckler said.

“It does not look like it will move transplacental, but calves are very susceptible once they are born,” the speaker reported. “You need to keep an eye on the calves and if they get bit by the tick, they will present within two weeks.”

In Illinois, the first case of Asian longhorned ticks was found in Morgan County and then Hamilton County, Steckler said. “This past summer they were found in Clay County, we have them in Pope County and it is just a matter of time before we find them in other counties,” she predicted.

For control, the speaker said, it looks like pour-ons are working. “Weigh your cattle so you get the correct dosage,” she stressed. “Fly tags may be necessary as well to keep the ticks from getting on the cattle’s’ faces and ears.”

Steckler does not recommend treating pastures. “The ticks will be down near the soil level and the products have to get on the tick to be effective,” she explained.

“Burning pastures can be one way to help reduce the number of ticks,” the speaker said. “But please consult somebody to help and understand when and how to burn because there is an art and science to burning pastures.”

There is no cure for theileriosis. “Treatment of clinical disease in affected cattle consists of supportive care focusing on hydration, nutrition and low-stress handling,” Steckler said.