Abstract

An ultrasonographic reproductive health examination in 2007 of a 26-yr-old female African elephant (Loxodanta africana) showed bilateral ureteral wall thickening and dilatation. The bladder and both ureters were ultrasonographically normal in appearance near the trigone, however cranial-most aspects of the ureters were dilated and thickened for a length of 30–50 cm. The right ureter was less dilated (2.5 cm diameter) than the left (10 cm diameter). The left kidney had a slightly hyperechoic appearance. The same month, continually elevated blood creatinine (3.0 mg/dl) and urine protein:creatinine (UPC) ratio (4) were observed. Chronic renal failure was diagnosed based on these abnormalities and persistent ureteral dilation on subsequent ultrasound examinations.

The elephant was monitored for 2.5 yr with weekly CBCs, serum chemistries, and urinalyses. Initially, specific gravity remained between 1.010 and 1.022, but dropped to 1.002–1.006 by mid-2009. In the fall of 2009, UPC and creatinine began to decline. Hypophosphatemia (2.0–2.6 mg/dl) and hypercalcemia (20–22.5 mg/dl) including an elevated ionized calcium (2.2 mmol/L), developed. Ultrasound showed increasing dilatation of the right ureter (8 cm), hydronephrosis of the left kidney, and prominent sacculation of the left ureter. Lethargy, ventral edema and oral mucosal ulceration acutely developed, presumably secondary to renal failure. Due to rapid clinical decline and grave prognosis, humane euthanasia was elected. Bilateral ureteral dilatation, aplasia of the right kidney (right: 0.57 kg; 19.5 x 11.5 x 3 cm; left: 8.57 kg; 37.5 x 24 x 11.5 cm), and chronic renal failure of the left kidney were identified at necropsy.