Regional variation of the manifestation, prevalence, and severity of giraffe skin disease: A review of an emerging disease in wild and captive giraffe populations

• Giraffe skin disease manifests as skin wrinkles, lesions or raw fissures on several body parts of affected giraffe.
• There is variation in the manifestation, prevalence, and severity of giraffe skin disease in wild populations of giraffe.
• Ruaha National Park has the highest apparent prevalence, with 79.8% of the observed giraffe showing signs of the disease.
• Preliminary studies suggest the disease is caused by a nematode and further complicated by secondary fungal infection.

Large mammals have drastically declined in the past few decades yet we know little about their ecology. Giraffe numbers for instance, have dropped by more than 40% in the last 15 years and recently, a skin disease, has been observed in numerous giraffe populations across Africa. The disease(s), commonly referred to as giraffe skin disease (GSD), manifests as lesions, wrinkled skin, and encrustations that can affect the limbs, shoulder or neck of giraffes. Here, we review GSD cases from literature reports and surveying efforts of individuals working with giraffes in the wild and in captivity. The aim of this review was to describe spatial variation in the anatomical location of lesions, prevalence, and severity of GSD. In total, we retrieved 16 published sources that referenced GSD and we received 63 respondents to our survey. We found that GSD has been observed in 13 protected areas across 7 countries in Africa and in 11 out of 48 zoos distributed across 6 countries. The prevalence of GSD in wild populations ranged from 2% to 80% of observed giraffes. Although little research to date has focused on GSD, our review reveals that the disease is more prevalent than initially thought and more severe in some areas than previously assumed. With vast areas of Sub-Saharan Africa still without information on GSD, researching the prevalence and conservation impacts of this disease should be a priority. We propose broader and longer-term studies to further describe and comprehend the effects of GSD on giraffe vital rates among populations in the wild and in captivity.