Ivermectin For The Treatment Of Psoroptic Scabies In Elk (Cervus elaphus nelsoni) And Rocky Mountain Bighorn Sheep ( Ovis canadensis canadensis)

Authors(s): A. Muschenheim

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Publication Date: 0000-00-00

Type: MS

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Abstract: Psoroptic scabies is a major cause of winter mortality of mature bull elk on the National Elk Refuge, Wyoming. Studies to test the efficacy of ivermectin to control scabies in elk were initiated with a toxicity trial on six elk calves. No ill effects were observed. Seventeen naturally infected mature bull elk were captured on the National Elk Refuge for a controlled study; five served as untreated controls and 12 were treated with ivermectin. No live mites were observed on treated animals through two months posttreatment. Reinfestation was observed at 14 weeks posttreatment. Some treated bulls were as severely infested as controls one year after treatment. Nineteen naturally infested bull elk were captured and fitted with radio collars. Half were treated with live ivermectin and half served as controls. One year posttreatment a lower percentage of treated animals were infested. Psoroptic scabies was a factor in the decline of bighorn sheep populations. Three Wyoming herds are known to be infested. Eight naturally infested bighorn sheep were captured and fitted with radio collars. Six were treated with ivermectin, two served as controls. One year after treatment five treated animals and one control had no clinical signs. One treated had signs in the ears.

Keywords: Wyoming Cooperative Fish and Wildlife Research Unit, University of Wyoming, National Elk Refuge, Jackson Hole, Teton County, disease, scabies, mortality, population, radio collar, animal, mammal, ungulate, elk, Cervidae, wapiti, Cervus elaphus, Rocky Mountain bighorn sheep, sheep, bighorn sheep, Ovis canadensis, Bovidae, mortality, radio collar