Demodectic Mange, Dermatophilosis, and other parasitic and bacterial dermatologic diseases in free-ranging white-tailed deer (Odocoileus virginianus) in the United States from 1975-2012

Authors: NEMETH, NICOLE - University Of Georgia; Ruder, Mark; GERHOLD, RICHARD - University Of Tennessee; BROWN, JUSTIN - University Of Georgia; MUNK, BRANDON - University Of Georgia; OESTERLE, PAUL - University Of Georgia; KUBISKI, STEVEN - University Of California; KEEL, KEVIN - University Of California

Submitted to: Veterinary Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/20/2013
Publication Date: 8/2/2013
Publication URL: http://doi: 10.1177/0300985813498783
Citation: Nemeth, N., Ruder, M.G., Gerhold, R., Brown, J., Munk, B., Oesterle, P., Kubiski, S., Keel, K. 2013. Demodectic Mange, Dermatophilosis, and other parasitic and bacterial dermatologic diseases in free-ranging white-tailed deer (Odocoileus virginianus) in the United States from 1975-2012. Veterinary Pathology. 00(0):1-8.

Interpretive Summary: White-tailed deer are a common and widespread species in North America. Unlike some diseases of wild animals with more cryptic symptoms, dermatologic diseases are often readily observed by hunters and other wildlife enthusiasts and many of these cases are submitted for diagnostic investigation. The records of white-tailed deer diagnosed with a dermatologic disease that were submitted to the Southeastern Cooperative Wildlife Disease Study (University of Georgia) over a 37 year period were retrospectively examined. The majority of skin diseases were found to be caused by Demodex sp.(parasitic) or Dermatophilus congolensis (bacterial), but other less common pathogens included other bacteria, fungi, ectoparasites, and larval nematodes. The impact of these skin diseases on populations of white-tailed deer is likely minimal; however, due to their dramatic presentation, demodicosis, dermatophilosis, and other infectious skin diseases can be of concern to hunters and in some cases, may have zoonotic potential. This study furthers our understanding of some of the causes of infectious dermatologic disease of free-ranging white-tailed deer and will be of interest to wildlife managers, wildlife health professionals and veterinary pathologists.

Technical Abstract: The white-tailed deer (Odocoileus virginianus) is a common and widespread North American game species. To evaluate the incidence, clinical manifestations, demography, and pathology of bacterial and parasitic dermatologic diseases in white-tailed deer in the southeastern United States, we retrospectively evaluated white-tailed deer cases submitted to the Southeastern Cooperative Wildlife Disease Study from 1975-2012. Among 2,569 deer examined, bacterial or parasitic dermatologic disease was diagnosed in 88 (3.4%) individuals, with Demodex sp.(n=38; 43.2%) and ermatophilus congolensis (n=19; 21.6%) as the most common causes. Demodicosis was significantly more common in deer over two years of age, and was most often detected in the fall; no statistically significant gender predilection was identified. Affected animals had patchy to generalized alopecia, often distributed over the head, neck, limbs and trunk; microscopic lesions included epidermal crusts and cutaneous nodules with mild perifollicular, lymphoplasmacytic inflammation. Dermatophilosis was most common in males less than one year of age that were often found dead. Crusting, erythema and alopecia occurred on the face, ears, and distal extremities. Less commonly, infectious dermatologic diseases were associated with other bacteria (n=13; 14.8%), fungi (n=5; 5.7%), ectoparasites (chiggers, lice, mites, and ticks; n=11; 12.5%) and larval nematodes (n=7; 8.0%). Population-level effects of these diseases in white-tailed deer are likely minimal; however, due to their dramatic presentation, demodicosis, dermatophilosis, and other infectious skin diseases can be of concern to hunters and in some cases, may have zoonotic potential.