Assessment of characteristics and severity of giraffe skin disease in Tarangire, Manyara ecosystem

Abstract

Giraffe Skin Disease (GSD) is a recently observed illness, mainly affecting adult and sub adult giraffes, causing gray or crusty lesions on giraffe body. The general objective of this study was to assess and characterize GSD and its severity in Tarangire-Manyara Ecosystem (TME). The study used road transects to gather field information on GSD. Eighty-four giraffes were sighted by systematic random sampling in the six study sites. Examination of giraffes involved body distribution of lesions, severity of the lesions and whether they were associated with age and sex of the affected giraffes. Five giraffes with GSD were immobilized in Tarangire National Park and Burunge Wildlife Management Area for tissue collection and histopathological analysis and blood for hematological and biochemical analysis. Overall GSD prevalence was (69%,), affected animals typically had 1-5 lesions which were mostly moderate and were predominantly observed on the forelegs. GSD positivity rate was higher among females 54% versus males, whereas males had a higher rate of severe lesions and generally had more lesions than females. Calves showed no lesions. All tissue sections stained routinely with Hematoxylin and Eosin (H-E) and then to the special Grocott Methenamine Silver (GMS) staining showed the presence of large quantities of fungal elements (hyphae and spores). However, haematological parameters examined and biochemical profile analysis showed changes associated with the presence of fungus infection. Our findings suggest the involvement of fungal infection in GSD pathogenesis. We recommend further characterization of the lesions using modern molecular techniques and culture to identify primary and secondary or opportunistic etiologies, and the order in which the pathogens occur in the lesions.Giraffe Skin Disease (GSD) is a recently observed illness, mainly affecting adult and sub adult giraffes, causing gray or crusty lesions on giraffe body. The general objective of this study was to assess and characterize GSD and its severity in Tarangire-Manyara Ecosystem (TME). The study used road transects to gather field information on GSD. Eighty-four giraffes were sighted by systematic random sampling in the six study sites. Examination of giraffes involved body distribution of lesions, severity of the lesions and whether they were associated with age and sex of the affected giraffes. Five giraffes with GSD were immobilized in Tarangire National Park and Burunge Wildlife Management Area for tissue collection and histopathological analysis and blood for hematological and biochemical analysis. Overall GSD prevalence was (69%,), affected animals typically had 1-5 lesions which were mostly moderate and were predominantly observed on the forelegs. GSD positivity rate was higher among females 54% versus males, whereas males had a higher rate of severe lesions and generally had more lesions than females. Calves showed no lesions. All tissue sections stained routinely with Hematoxylin and Eosin (H-E) and then to the special Grocott Methenamine Silver (GMS) staining showed the presence of large quantities of fungal elements (hyphae and spores). However, haematological parameters examined and biochemical profile analysis showed changes associated with the presence of fungus infection. Our findings suggest the involvement of fungal infection in GSD pathogenesis. We recommend further characterization of the lesions using modern molecular techniques and culture to identify primary and secondary or opportunistic etiologies, and the order in which the pathogens occur in the lesions.