Efficacy of ivermectin against the mange mite Sarcoptes scabiei var suis in pigs.

The efficacy of ivermectin administered by esophageal intubation in a single dose was evaluated against the mange mite Sarcoptes scabiei var suis in 24 naturally infested pigs. Six pigs were allocated to each of the 4 treatment groups. Control (group 1) pigs were given nonmedicated water, group 2 were given ivermectin at 300 micrograms/kg of body weight, group 3 were given ivermectin at 400 micrograms/kg, and group 4 were given ivermectin at 500 micrograms/kg. The pigs were examined for S scabiei before treatment and on days 7, 14, 21, and 28 after treatment. Of the 18 ivermectin-treated pigs, 10 had no live S scabiei recovered on day 7 after treatment, 16 had none on day 14, 18 had none on day 21, and 16 had none on day 28. All 6 nonmedicated control pigs had live S scabiei recovered on days 7 and 21, and 5 control pigs had mites on days 14 and 28. The single administration of ivermectin given by esophageal intubation was highly effective in reducing the number of S scabiei at all dose levels tested. The pooled ivermectin-treated groups had significantly (P less than 0.01) fewer mites than the control group on all posttreatment examination days. There were no statistically significant differences among the ivermectin dose levels.