Use of remote cameras to monitor the potential prevalence of sarcoptic mange in wild mammals from Southern Texas

Sarcoptic mange, which is caused by the mite (Sarcoptes scabiei) is a common, highly contagious skin disease that has been reported from more than 100 species of mammals, including humans. Prevalence of mange in North American... [ view full abstract ]

Sarcoptic mange, which is caused by the mite (Sarcoptes scabiei) is a common, highly contagious skin disease that has been reported from more than 100 species of mammals, including humans. Prevalence of mange in North American mammals has ranged from 11% to >80% during epizootic peaks. Severe mange has resulted in about 80% mortality and reduced ovulation and pregnancy rates in surviving adult females. Such a disease can devastate local wildlife populations, and is especially concerning when endangered mammals, such as ocelots (Leopardus pardalis), are at risk. Our objective was to 1) document the current prevalence of mange in wild mammals of southern Texas, and 2) determine the efficacy of using remote cameras to estimate mange prevalence. We collected blood and skin samples from 166 mammals representing 12 species from southern Texas during 2012. Five species (16/25 feral hogs (Sus scrofa), 7/28 white-tailed deer (Odocoileus virginianus), 18/25 coyotes (Canis latrans), 1/5 nilgai (Boselaphus tragocamelus), and 5/20 raccoons (Procyon lotor)) displayed alopecia, seborrhea, and crusted lesions consistent with mange. Only feral hogs, coyotes, and white-tailed had mites present within skin samples. Titers ranged from ‘Not appreciable’ to 1:1,024 in sera from all animals, with titers from mite-positive animals higher (mean = 1:212; range = NA – 1:1,024; χ2 = 25.1; P < 0.001; df = 10) than from animals that were negative for mites (mean = 1:8; range = NA – 1:64). Two photographs of each collected animal were reviewed in a blind trial by a veterinarian experienced with cases of mange. The veterinarian correctly identified 18 and 97 photographs as positive and negative for mange, respectively, with 19, 9, and 23 photographs being false positive, false negative, and inconclusive, respectively. Moderate to severe cases of mange were readily identifiable via photographs; however, mild cases often were misdiagnosed from photographs.