A tick new to Pennsylvania is known to carry Lyme disease and a disease that can hurt milk production in dairy cows.
Tests by the National Veterinary Services Laboratory in Ames, Iowa have confirmed the presence of the Asian, or longhorn tick, Haemaphysalis longicornis, in Pennsylvania.
An invasive species that congregates in large numbers, the longhorn tick can cause anemia in livestock. The tick was discovered on a wild deer in Centre County. It is known to carry several diseases that infect hogs and cattle in Asia. So far, ticks examined in the U.S. do not carry any infectious pathogens.
“Even experts have difficulty distinguishing among tick species, so it is important to take precautions to protect pets, livestock and family members from becoming a host for ticks of any kind,” State Veterinarian Dr. David Wolfgang said. “Scientists don’t yet know how this species will adapt to the North American climate and animal hosts, but we know it survived New Jersey’s winter and has infested sheep and cattle in this region.”
Easily confused with other tick species, including the rabbit tick, which is common in the Eastern U.S., the species’ distinctive “horns” may not be visible without a microscope. The Asian tick infests host animals in dense clusters of numerous ticks. Female Asian ticks reproduce asexually, so a single tick can reproduce and lay 2,000 eggs after feeding on a host. Cattle, pets, small mammals, birds and humans are all potential hosts.
“The discovery of the longhorn tick is another reminder of the importance of tick prevention for Pennsylvanians,” Secretary of Health Dr. Rachel Levine said. “Ticks can be found in your own backyard, so it is essential to wear long sleeves and pants, use insect repellant containing DEET to help keep you safe from ticks and the diseases they carry. It is also important to check yourself and your pets for ticks, as pets can bring ticks indoors.”
Native to East and Central Asia, the tick was originally identified in the U.S. in New Jersey, where it was found in large numbers in sheep in Mercer County in 2017. It has also been found in New York, Arkansas, New Jersey, West Virginia, Virginia and North Carolina.
Wolfgang recommends examining animals on a regular basis, and checking for ticks after being outside to prevent tick bites and disease transmission. Livestock producers and pet owners should consult their veterinarians to develop tick prevention and control appropriate to their specific animals. To reduce tick habitat, maintain a nine-foot distance between lawn or pasture and wooded areas, keep grass height low, and remove weeds and brush bordering wooded areas.
Unfed ticks can live nearly a year. They have been found on a variety of wild animals, birds, pets and humans. An infestation spreads quickly in farm animals.
The longhorned tick can transmit an animal disease called theileriosis to livestock. The disease can reduce milk production in dairy cows and cause blood loss in and the occasional death of calves. Sheep farmers can see poorer wool.
Lyme spirochetes and other organisms causing disease in humans have been detected in longhorn ticks in China.