THEILERIOSIS OF SHEEP AND GOATS IN CHINA

Theileriosis is an important disease of sheep and goats in West China. Its main distribution includes Qinghai, Gansu, Ningxia, Inner Mongoli a, Shaanxi and Sichuan. The epidemic period is from late March to July with April-May being the peak months. This is the period of most inte nsive tick attack by Haemaphysalis qinghaiensis (77.2-99.24%) during t he year. It has been proved that the nymphs and adults, which develop from larvae and nymphs engorged on infected sheep or goats can transmi t the pathogen. Experimental infections revealed the incubation period , clinical signs and the pathogen's morphological characteristics. The disease was more serious in lambs and exotic adult animals than nativ e adult animals. The sickness rates of lambs, exotic and native adult animals were 78-85%, 41% and 9% respectively; death rates were 81.4%, 62.5% and 65% respectively. Clinical prophylaxis, chemical therapy and destruction of ticks have been carried out with antiparasitic compoun ds to control the disease since 1982. Experiments demonstrated that th e curative rate was up to 76-86%, but not satisfactory prophylactic me thods were found.