Ticks and Disease
Though D. variabilis may be exposed to Borrelia burgdorferi, the causative agent of Lyme disease, these ticks are not competent vectors for the transmission of this disease.The primary vector for Borrelia burgdorferi is the deer tick Ixodes scapularis in Eastern parts of the United States, and Ixodes pacificus in California and Oregon. Dermacentor variabilis may also carry Anaplasma phagocytophilum, the causative agent of HGE (human granulocytic ehrlichiosis), and Ehrlichia chaffeensis, the causative agent of HME (human monocytic ehrlichiosis).
Ticks of Domestic Animals
Ticks of domestic animals directly cause poor health and loss of production to their hosts by many parasitic mechanisms. Ticks also transmit numerous kinds of viruses, bacteria and protozoa between domestic animals. These microbes cause diseases which can be severely debilitating or fatal to domestic animals, and may also affect humans. Ticks are especially important to domestic animals in tropical and subtropical countries. Here the warm climate enables many species of ticks to flourish. Also the numerous wild animals in warm countries provides a reservoir of ticks and infective microbes that spread to domestic animals. Farmers of livestock animals use many methods to control ticks and there are related treatments to reduce infestation of companion animals. Veterinarians and animal health agencies work at private, national and international scales to reduce the harm caused by ticks and their associated diseases.