# Sarcoptic Mange in Reintroduced Red Foxes (Vulpes vulpes) in South Korea: Case Histories, Clinical Assessments, Treatments, and Pathological Findings

## TL;DR

This study reports on sarcoptic mange in reintroduced red foxes in South Korea, detailing clinical cases, treatments, and outcomes to improve fox survival and population health.

## Contribution

The first documented clinical cases and treatment outcomes of sarcoptic mange in reintroduced red foxes in South Korea.

## Key findings

- 15 rescued foxes showed blood markers of chronic infection, with 12 successfully treated with ivermectin or fluralaner.
- Necropsy of 12 dead foxes revealed typical skin lesions of sarcoptic mange.
- Long-term monitoring and continuous treatment are critical for managing sarcoptic mange in reintroduced fox populations.

## Abstract

The red fox (Vulpes vulpes) became extinct in South Korea, and a restoration project through reintroduction of these foxes has been ongoing since 2012. Sarcoptic mange, a parasitic skin disease, has been a major threat to reintroduced foxes since the project’s initiation. Between 2019 and 2024, 27 cases of sarcoptic mange infections were identified in 26 red foxes. In 15 of these cases, where the foxes were rescued alive, clinical assessments, including physical examinations, blood tests, and treatments, were conducted, and their results were documented. For 12 foxes found dead, pathological findings were confirmed through necropsy. This study presents the first report of clinical cases of sarcoptic mange infection in reintroduced red foxes in South Korea and aims to contribute to improving individual survival rates and promoting the establishment of healthy red fox populations.

Sarcoptic mange is a highly contagious and often lethal parasitic skin disease caused by the mite Sarcoptes scabiei, which is frequently reported in red foxes (Vulpes vulpes). However, there is a lack of documented cases and treatment strategies for sarcoptic mange in reintroduced red fox populations, particularly in South Korea. This study describes 27 cases of sarcoptic mange outbreaks in 26 red foxes reintroduced into South Korea between 2019 and 2024. Of these, 15 foxes were rescued alive, while 12 were found dead. Blood tests of the surviving animals (n = 15) showed significant leukocytosis, anemia, decreased albumin levels, increased globulin levels, elevated blood urea nitrogen levels, and decreased creatinine levels, indicative of a chronic wasting infection. Treatment with ivermectin or fluralaner resulted in complete recovery in 12 of 15 animals, while three animals died during treatment. Necropsy of the deceased animals (n = 12) revealed characteristic skin lesions, such as alopecia, hyperkeratosis, epidermal hyperplasia, and dermatitis. The study findings highlight the importance of long-term monitoring and active, continuous treatment of sarcoptic mange, a major threat, for the stable re-establishment of reintroduced foxes in South Korea.