USE OF BAIT CONTAINING TRICLABENDAZOLE TO TREAT FASCIOLOIDES MAGNA INFECTIONS IN FREE-RANGING WHITE-TAILED DEER

Triclabendazole-medicated corn bait was given to white-tailed deer (Od ocoileus virginianus) on the Welder Wildlife Refuge, Sinton, Texas (US A), at a dose of 11 mg/kg body weight per deer per day for seven days, for control of Fascioloides magna. Medicated bait was offered for one week each during the winters of 1987, 1988, and 1989. Deer collected from treated areas, from baited control and four weeks after the end o f the baiting period in each of three years. Prior to the study, preva lence of fluke infection was 68%. After treatment with triclabendazole medicated corn, 13 (56%) of 23 deer collected were infected with fluk es of which 15% had live parasites; this was evidence for therapeutic treatment. Of the deer collected in the baited and unbaited control ar eas, 63% and 80%, respectively, were infected only with live flukes. P revalence of live flukes in deer was significantly (P < 0.05) lower in the treatment pasture than in the baited or unbaited control areas in each of the three years. Efficacy of the baiting system over the thre e years was 63% when comparing the treatment area and the baited contr ol area.