HEMOGLOBINURIC NEPHROSIS IN A RHEA (RHEA-AMERICANA)

An eighteen-month-old female rhea (Rhea americana) was presented dead for necropsy. The owner reported having observed blood in the dropping s. Gross examination revealed a rhea in good body condition with a cop ious amount of frank blood in the cloaca. Large masses of matted fescu e grass (Festuca spp.) distended the ventriculus and jejunum. No hemor rhage was evident in the digestive tract, which was otherwise void of ingesta. The kidneys were dark brown in color. Renal histopathology re vealed a severe accumulation of eosinophilic pigment in the tubular ep ithelial cells of the proximal convoluted tubules, with tubular nephro sis and eosinophilic casts in the collecting tubules. It was concluded that the renal pigment was hemoglobin and not myoglobin, based on lac k of evidence of muscle injury and the severe erythrophagocytosis evid ent in hepatic macrophages. The renal pigment also stained positive wi th the hemoglobin-specific Okajima stain. Hemoglobinuric nephrosis has not previously been reported in an avian species.