Trypanosoma evansi control and horse mortality in the Brazilian Pantanal

The impact of three treatment strategies for Trypanosoma evansi control on horse mortality in the Brazilian Pantanal based on four size categories of cattle ranches is explored. The region's 49,000 horses are indispensable to traditional extensive cattle ranching and T. evansi kills horses. About 13 % of these horse would be lost, annually, due to T. evansi if no control we re undertaken. One preventive and two curative treatment strategies are fin ancially justifiable in the Pantanal. The best available technology for the treatment of T. evansi from a horse mortality perspective is the preventiv e strategy which spares 6,462 horses, annually. the year-round cure spared 5,783 horses, and the seasonal cure saves 5,204 horses on a regional basis relative to no control strategy. Regardless of the strategy adopted 39% of the cost or benefits fall to the largest ranches, while 18% fall to the sma llest ranches.