tick-borne fever
nounMedical Definition of tick-borne fever
: a usually mild rickettsial disease of ruminant animals (as sheep and cattle) especially in Europe that is caused by a bacterium of the genus Anaplasma (A. phagocytophilum synonym Ehrlichia phagocytophilia) which is transmitted by a tick of the genus Ixodes, and that is marked by fever, listlessness, and anorexia