Ticks are among the most significant parasites of large wild and domestic animals, as regards both economic loss and transmission of disease. While no species of tick is primarily a human parasite, some species do attack man when the opportunity presents itself. The tick-borne diseases of livestock constitute a complex of several diseases whose etiological agents may be protozoal, rickettsia, bacterial or viral.
Over 60 tick-borne agents may be pathogenic to livestock throughout the world. Tick-borne diseases are widely distributed throughout tropical countries. In general, the vecto ixodid ticks favour humid and subhumid zones. These diseases cause some of the most serious economic losses of ruminants in Africa (assuming that rinderpest is routinely controlled). In many countries, they are the major health impediments to efficient livestock production. On a global basis, the economic toll caused by tick-borne diseases is staggering. Exotic breeds of livestock are being imported into tropical and sub-tropical regions in increasing numbers, often in spite of their poor adaptation to local climatic conditions. Such cattle are especially susceptible to tick-borne diseases and the effects of tick infestation.