Bovine Anaplasmosis and Control

Abstract

Bovine anaplasmosis is one of the most important tick borne diseases of ruminants worldwide causing significant economic losses in the livestock industries due to the high morbidity and mortality in susceptible cattle herds. Bovine anaplasmosis, caused by Anaplasma marginale, is an infectious but non-contagious disease. The mode of transmission of bovine anaplasmosis includes mechanical (blood contaminated fomites (needles, ear tagging, dehorning and castration equipment), biological (tick bites) and transplacental (mother to fetus). Bovine Anaplasmosis occurs in tropical and subtropical regions worldwide. Cattle of all ages are susceptible to infection with A. marginale, but the severity of disease increases with age. The common clinical sign of bovine anaplsmosis includes; fever, anorexia, rapid loss of body condition, severe decrease in milk production, pale and icteric mucous membranes, increased heart and respiratory rates, muscle weakness and depression. Diagnosis of bovine anaplasmosis can be made by demonstration of A. marginale on stained blood smears from clinically infected animals during the acute phase of the disease, but it is not reliable for detecting infection in pre-symptomatic or carrier animals. Instead, serological demonstration of antibodies and confirmation of antigen with molecular detection tools are used for diagnosis. Anaplasmosis can be treated by administration of oxytetracyclines, however oxytetracyclines do not clear the parasite from carrier animals. Control measures for bovine anaplasmosis vary with geographical location and include maintenance of Anaplasma free herds, vector control, administration of antibiotics and vaccination. Intensive acaridae application to control ticks has a number of limitations, therefore, immunization together with strategic tick control is recommended for exotic and crossbred cattle. Further studies on epidemiology of bovine anaplasmosis is needed