A New Tick Threat in the United States – The Longhorned Tick

Audra Stillabower, CVT
Veterinary Information Specialist

In August of 2017, a woman in New Jersey was infested with thousands of ticks after shearing her sheep that was also infested. This tick was tested and found to be a tick that was new to the United States. The tick is the Haemaphysalis longicornis, also known as the East Asian or Longhorned tick.  This tick is normally found in Russia, Korea, China and Japan. It has also been found in Australia, New Zealand and several Pacific Islands. It is a mystery how the tick came to be in the United States on a farm in New Jersey. The sheep that was found to be infested had not been overseas. Researchers believe that the tick has been here for years already.

When investigators went to the farm with the infested sheep, they were immediately besieged by ticks as soon as they stepped into the pasture. While they were able to treat the area and remove the ticks, they have spread and have been found in several other counties in New Jersey and have also been found in Virginia, Arkansas and West Virginia.

There aRe many reasons why this foreign tick is a concern to the United States. The Longhorned tick can transmit tick borne diseases such as SFTS (severe fever with thrombocytopenia syndrome). This infectious disease can cause a low platelet count and multiple organ failure. While SFTS has been an issue in countries like China, there have been no reported cases of SFTS in the U.S. The ticks also have the potential to carry Lyme disease, Anaplasma, Ehrlichia and Borrelia.

Longhorned ticks do not need a male to reproduce. Well fed female ticks can reproduce without males making it much easier for larger populations of ticks that can overwhelm areas with huge numbers. The female tick will clone itself and lay up to 2000 eggs. This process is faster than traditional mating. Traditional North American ticks can take up to 2 years for the entire reproduction cycle where the Longhorned tick will take only 6 months. This can lead to larger tick infestations in a shorter amount of time.

This tick will burrow underground in the winter to avoid freezing temperatures. Research done in New Jersey found that these ticks successfully survived the winter which can lead to higher numbers of ticks and making them more difficult to eradicate.

While some tick species will prefer certain types of hosts and their feeding is limited to those species, the Longhorned tick will feed on almost any bird or animal. This includes humans as well. They have been known to feed in such numbers that they have completely exsanguinated the host.

While some of the facts on the Longhorned tick are alarming, they may be more of an issue for livestock and wildlife than for humans. It is important to keep household pets on a tick preventative and take precautions when out in tall grasses or wooded areas where ticks are known to be. Check yourself and your pets after being out in these areas or even daily if you live in a heavily infested area.

The CDC states to treat clothing and gear with products containing 0.5% permethrin and to use Environmental Protection Agency (EPA)-registered insect repellents containing DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. These products are only for use on a human. Only veterinary recommended products should be placed on a pet. When going out, tuck your pants into your socks and wear long sleeved shirts. Wear light-colored clothing to make it easier to see ticks.

Farmers should check their livestock for ticks regularly. If you spot any unusual looking ticks or large infestations, report this to your local health department so they can investigate.  Being vigilant and taking precautions while outside can help protect you and your pets this summer.


For more information on protecting yourself and your pet from ticks: