Status of Surra in Livestock in Thailand

抄録

Surra was first detected in mules in Rachaburi province, Thailand in 1949 but it is now known to occur throughout Thailand not only in horses, but also in cattle, buffaloes, pigs, dogs and deer with varying clinical manifestations. The most severe clinical cases usually occurs in infected horses. Abortion at late stages of pregnancy or premature parturition have been reported in infected buffaloes, cattle and pigs. Nervous signs caused by Trypanosoma evansi invading the central nervous system have also been observed in infected cattle and more recently in hog deer.
Prevalence rates for this disease vary between 12.5%, 20% and 4.6% in cattle, buffaloes and pigs, respectively. The economic losses caused by surra are considerable, particularly where they impact upon the small holder farmer. These losses accrue through the effects of disease upon piglet and calf production, loss of draught power in buffalo and the reduction in meat and milk production in infected animals. Although no estimates of these costs has yet been realized, it has been suggested that the cost of treatment with trypanocidal drugs in order to control the disease would be substantial, in the order of US＄7.6 million. More effort is required to determine the extent of the losses in livestock productivity due to trypanosomosis and the benefits of intervention.