Use of Remote Cameras to Monitor the Potential Prevalence of Sarcoptic Mange in Southern Texas, USA.

Sarcoptic mange, 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. Our objectives were to 1) determine the prevalence of sarcoptic mange within mammals from southern Texas, and 2) determine the efficacy of using remote cameras to estimate mange prevalence. We collected remote camera photographs from a 64-km2 area and blood and skin scrapings from 166 mammals representing 12 species in southern Texas, US during 2012-13. Only 16% of the 344,395 photograph series were of animals with an appearance consistent with sarcoptic mange and only individuals of four species: 16/25 feral hogs ( Sus scrofa ), 13/28 white-tailed deer ( Odocoileus virginianus ), 18/25 coyotes ( Canis latrans ), and 1/5 nilgai ( Boselaphus tragocamelus ) displayed alopecia, seborrhea, and crusted lesions that were consistent with mange. However, only feral hogs, coyotes, and white-tailed deer had mites present within skin scrapings. Two photographs of each collected mammal that displayed characteristics consistent with mange (n=83 animals; 166 photographs) were reviewed in a blind trial by a veterinarian experienced with cases of mange. The veterinarian correctly identified 18 and 97 animals from photographs as positive and negative for mange, respectively, with 19, 9, and 23 animals from photographs being false positive, false negative, and inconclusive, respectively. Moderate to severe cases of mange were readily identifiable via photographs; however, mild cases and summer coats often were misdiagnosed, making the technique of debatable use.