Chronic iron toxicosis in two donkeys: considering the impact of environmental iron

Liver disease in donkeys is common but aetiology is rarely identified. Iron accumulation in liver biopsies is often seen but is a non-specific finding. In this report we describe two donkeys that were presented for treatment of hepatic encephalopathy. Biochemical analyses were consistent with liver failure, measurement of serum iron-related parameters indicated iron overload, and histopathological analysis of liver biopsies showed fibrosis and marked diffuse hemosiderin deposition, suggesting iron toxicosis. Iron measurement in water, grass and soil confirmed exposure. The farm where the animals were housed is situated in a region historically important for coal and shale oil mining, which are associated with heavy metal contamination of soil and water. Iron toxicosis is an important differential diagnosis when clinicians are dealing with cases of liver disease, especially in either spent or active mining areas. No single test is confirmatory of diagnosis and sampling co-grazers and their environment is recommended.