Cloisonné kidney in mouflon sheep (Ovis orientalis musimon)

Abstract

This study describes a case of cloisonné kidney associated with infection by Babesia ovis in a wild mouflon (Ovis orientalis musimonj found dead in year in eastern Sierra Morena (Andalusia, Spain). The major macroscopic lesions were a) icteric coloration in ocular and oral mucosa, and b) dark metal coloration on the kidneys' external surface. Intense dark coloration alternating with intense greyish strips was observed on renal cortex sections. Blood samples were collected for haematological and parasitological analyses, as well as samples from various organs for histopathological examination. Infection by B. ovis was confirmed by using the Polymerase Chain Reaction test (PCR). Histopathological examination revealed tubulonephrosis associated with thickening of the basal membrane of the convoluted portions of the renal tubules (both proximal and distal), which took on an intense brownish pigmentation. These renal lesions have been described as "cloisonné" kidney. Cloisonné kidneys show uncommon coloring of the renal tubular system, associated with ferritin and hemosiderin deposits in these structures resulting from a chronic hemolitic process (hemoparasites, toxins, etc.). In our case, hemolitic phenomena are associated with infection by B. ovis. The seroprevalence of this hemoparasite in wild mouflon populations in other regions of Spain (Catalonia) is up to 15%.