A case of amyloidosis-induced hepatomegaly in a horse

Amyloidosis is a rare condition involving the deposition of insoluble amyloid fibrils in various organs, potentially leading to organ dysfunction. In this case report, a ten-year-old Dutch warmblood mare is described with hepatic amyloidosis, which was not associated with the commonly seen antiserum production. The mare showed signs of lethargy, fever and anorexia, and blood analysis revealed elevated liver enzymes and severe anemia. Ultrasonographic examination of the abdomen revealed an enlarged liver with ascites. Histopathological examination confirmed amyloid deposits in the liver, primarily in the space of Disse. Stokes’ Congo Red staining highlighted the amyloid presence, which was most pronounced around the portal areas, but also extending toward the terminal hepatic vein. Despite treatment, the condition worsened, leading to euthanasia. In this case, the need for thorough histopathologic diagnostic examination in hepatomegaly cases is underscored.