Cattle Tick & (Boophilus) Microplus

Boophilus microplus is a species of fever tick that infests cattle. A second species of this tick is Boophilus annulatus. They are commonly called fever ticks because they are capable of injecting cattle with a protozoan called Babesia bovis or Babesia bigemina. The protozoa cause tick fever, which results in a fast and brutal death in as much as 90 percent of infected cattle.

  1. History

    • Cattle drives during the 1800s helped spread the fever tick.

      Historians feel that fever ticks and tick fever were introduced into the United States, possibly as early as 1610, through importation of cattle from the Spanish Colonies of the West Indies and Mexico. By early 1800, tick fever was reported in Virginia and North Carolina, and by 1877 tick fever was causing alarm throughout the country, especially along cattle-drive trails. Fever ticks had been eradicated in the United States by 1943 and a permanent quarantine zone was established along the Texas/Mexico border.

    Significance

    • There is a permanent fever tick quarantine zone along the Rio Grande River in Texas.

      The permanent quarantine zone still exists today and is an approximate 500-mile-long swath of land along the Rio Grande River stretching from Brownsville to Del Rio. It ranges in width from several hundred yards to approximately 10 miles. In 2007 and again in 2008, fever ticks were found outside the quarantine zone. Because of these detections, there are now more than one and a half million acres under quarantine.

    Identification

    • Fever ticks found on cattle can be identified by their characteristics.

      Several different tick species infest cattle, but the fever tick has its own distinct characteristics. It has short and relatively broad head parts, which are dark reddish brown or chestnut brown in color. The tick's body is oval in shape and varies in color from a dull yellow to an olive brown. Often the body is mottled with irregular areas of yellow and brown or streaked with wavy lines of these colors. The fever tick's eight legs are brown, moderately long and slender.

    Hosts

    • Deer and other wildlife can be infested with fever ticks.

      Horses, deer and exotics such as nilgai, elk, aoudad sheep and fallow, axis and red deer can act as host for fever ticks. According to the Texas Animal Health Commission, protozoan-infected fever ticks are unlikely to cause death in animals other than cattle. Fortunately, the protozoa are not harmful to humans.

    Treatment for Fever Ticks

    • Cattle are treated for fever ticks by driving them through a vat filled with a tickicide mixture.

      If fever ticks are found on a ranch, the rancher has two options. Option 1 is to dip every cow in the infected area every 14 days for nine months. With Option 2, cattle are dipped twice, 14 days apart regardless of whether they have fever ticks. Within this period, the cattle are required to have two tick-free inspections by the federal government. When the cattle are tick free, they can be moved to a new, tick-free pasture. The tick-infested pasture is then left empty for nine months so the ticks will die of starvation.

    Tick Fever Symptioms

    • A cow with tick fever loses weight, becomes weak and quits eating.

      The Boophilus protozoa attack a cow's red corpuscles, which causes acute anemia and an enlarged liver and spleen. The animal loses weight, becomes weak, quits eating and usually dies.

    Misconceptions

    • Cattle infested with fever ticks do not necessarily have tick fever.

      There is a common misconception that if a cow is infested with fever ticks, she is also infected with the tick fever disease. All fever ticks do not carry the protozoa that cause tick fever. There have not been any cattle in the quarantine zone diagnosed with tick fever.