A review of sarcoptic mange in North American wildlife

Abstract

The "itch mite" or "mange mite", Sarcoptes scabiei, causes scabies in humans and sarcoptic mange in domestic and free-ranging animals. This mite has a wide host range due to its ability to adapt to new hosts and has been spread across the globe presumably through human expansion. While disease caused by S. scabiei has been very well-studied in humans and domestic animals, there are still numerous gaps in our understanding of this pathogen in free-ranging wildlife. The literature on sarcoptic mange in North American wildlife is particularly limited, which may be due to the relatively limited number of clinically-affected species and lack of severe population impacts seen in other continents. This review article provides a summary of the current knowledge of mange in wildlife, with a focus on the most common clinically-affected species in North America including red foxes (Vulpes vulpes), gray wolves (Canis lupus), coyotes (Canis latrans), and American black bears (Ursus americanus).

Keywords: Mange; North America; Sarcoptes scabiei; Wildlife.

Graphical abstract

Fig. 1

Life stages of S. scabiei. Top left: Egg; Top middle: Larva; Top right: Protonymph; Bottom left: Tritonymph; Bottom middle: Adult Male; Bottom right: Adult Female.

Fig. 2

Microscopic lesions of a bear with sarcoptic mange. (A) Close-up view of hyperkeratotic and crusted skin showing a mite tunnel. (B) Histological section with cross-section of S. scabiei within the epidermis. (Asterisks: mite tunnels; arrowheads: epidermis; arrow pointing to S. scabiei).

Fig. 3

North American mammals with clinical sarcoptic mange. (A) Red fox with lesions on the face. (B) The same red fox showing a close up of the hyperkeratosis fissures in the skin. (C) Coyote with alopecia on the head and neck. (D) Gray wolf showing alopecia on the head, flanks, and hind limbs (Photo credit: Yellowstone Wolf Project/National Park Service). (E) Black bear in a culvert trap showing severe alopecia and skin thickening on the face, ears, and forelimb. (F) Black bear showing additional crusting and alopecia on the ears, flank, and muzzle; inset: close-up of hyperkeratotic and crusted skin.