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Abstract
There have been increasing reports of black bears (Ursus americanus) with severe skin disease across multiple states in the Eastern and mid-Western United States over the last three decades. The cause of these lesions in the majority of cases was determined to be sarcoptic mange due to the detection of Sarcoptes scabiei mites observed in skin scrapes. The emergence of this disease in black bears warranted investigating several basic epidemiological questions. To start, an extensive literature review was performed that described the natural history of S. scabiei including the history of the disease and taxonomy and life cycle of the mite, among other topics. The review also provided a comprehensive list of North American wildlife species that have been reported with sarcoptic mange, and finally summarizes what we know about this disease in four commonly-affected North American carnivore hosts: wolves (Canis lupus), coyotes (Canis latrans), red foxes (Vulpes Vulpes) and black bears. In the first research section, I attempted to determine the geographic extent and number of cases of sarcoptic mange in black bears. The second study attempted to determine if exposure to one of several pathogens commonly infecting black bears was a potential risk factor for clinical mange. The third study used a serological approach to determine the extent of exposure in bears without clinical disease to gain a better appreciation for which populations of bears are exposed to mites, and which populations may be at risk of disease in the future. The fourth study determined the ability of mites to survive off the live host and used these data to speculate on the role of indirect transmission of mites between black bears, a host species that is generally considered to be solitary. In addition to the utility of these studies in advancing our understanding of sarcoptic mange in wildlife, many of these studies can also be used to drive management decisions or lay the groundwork for future research of this disease in bears.