Infestation by Sarcoptes scabiei causes distinct differences in sarcoptic mange disease syndromes among sympatric carnivoran species

Abstract

Sarcoptic mange, caused by Sarcoptes scabiei, is a pan-emerging zoonotic disease, affecting new species and expanding into novel geographic locations in recent decades yet the distinct differences in disease syndromes between species remain poorly characterized and understood. This study investigated mange severity, mite burden, and immune response as characterized by dermapathology in sympatric carnivoran species in Pennsylvania, USA, assessing black bears (Ursus americanus), coyotes (Canis latrans), grey foxes (Urocyon cinereoargenteus), and red foxes (Vulpes vulpes). Scabietic and healthy individuals were evaluated using standardized metrics to assess health parameters between infested and healthy individuals and differences in mange disease syndromes between species. Mange severity varied significantly by species. Red foxes and black bears displayed more severe outward signs of mange infestation and higher mite burdens compared to coyotes, which exhibited milder physical and histologic signs of disease. Histologic analyses revealed significant differences in dermatologic lesions; black bears and red foxes more frequently had severe hyperkeratosis, acanthosis, and secondary bacterial and yeast colonization, while coyotes had fewer and milder lesions. In terms of mite detection, tissue digestions were the most sensitive method, followed by cytology and histology. Serological screening detected the highest S. scabiei exposure rates in coyotes (53 %), followed by black bears (37 %), red foxes (17 %), and grey foxes (12 %). Notably, many seropositive coyotes showed no physical signs of mange, suggesting potential resistance or recovery. In contrast, red foxes exhibited severe disease and low seroprevalence, consistent with high mortality and limited recovery. These findings highlight species-specific differences in sarcoptic mange manifestation and host responses. Coyotes may act as reservoirs, contributing to disease persistence in the ecosystem, while red foxes and black bears suffer higher morbidity. This study emphasizes the need for integrated diagnostic and surveillance approaches to improve understanding of S. scabiei epidemiology and inform wildlife management strategies.