Comparison of selamectin and imidacloprid plus permethrin in eliminating Leporacarus gibbus infestation in laboratory rabbits (Oryctolagus cuniculus)

A shipment of New Zealand white rabbits was infested with Leporacarus gibbus, a rabbit fur mite. This study compared the effectiveness of selamectin with that of imidocloprid plus permethrin in eliminating the mite infestation. Rabbits were divided into 2 groups, and either selamectin or imidocloprid plus permethrin was applied topically. Visual and microscopic examinations were performed on days 0, 1, 2, 3, 4, 5, 6, 13, and 27 for 5 sites (the left and right gluteal areas, neck, ventral tail, and abdomen). Mean percentage effectiveness for each treatment was calculated for each time point. Positive and negative predictive value, sensitivity, and specificity of visual examination were determined relative to microscopic assessment. In addition, location prevalence for the mites was determined. Both treatments were 100% effective by day 13, but selamectin was 100% effective by day 3. The positive predictive value of visual examination was 96%, its negative predictive value was 86%, sensitivity was 75%, and specificity was 98%. Parasite burden was most prevalent on the right and left gluteal areas. We conclude that although both imidocloprid plus permethrin and selamectin were effective against L. gibbus, treatment with selamectin more rapidly eliminated the infestation.