Evaluation of urinary and serum metabolites in Asian small-clawed otters (Aonyx cinerea) with calcium oxalate urolithiasis

Baseline renal function data was collected during 24-hr periods of feeding and fasting from three male and three female adult Asian small-clawed otter s (Aonyx cinerea) with calcium oxalate urolithiasis. Urine was analyzed for calcium, phosphorus, and oxalate, and urinalyses were performed. There was no evidence of glucosuria, which has been previously reported in Asian sma ll-clawed otters with urolithiasis. Urinary oxalate levels were quite high when compared with those of dogs and humans without uroliths, and the ratio of urinary oxalate to calcium was close to 1:1 during periods of food cons umption. There was no significant difference in urinary oxalate excretion b etween the fed and fasting states. Urinary calcium excretion was five times greater during feeding than during fasting. Calcium levels were higher in the otters than those reported for dogs without uroliths but were similar t o those for normal humans. Water consumption and urine production were sign ificantly higher during periods of food consumption. Serum chemistry analys es and electrolyte levels were also determined. There wets no evidence of h ypercalcemia. Fractional clearance of calcium and phosphorus and endogenous creatinine clearance were significantly higher during food consumption tha n during fasting. Parathyroid hormone levels were similar to those reported for dogs and cats. Serum 25-hydroxy-vitamin D was slightly lower in the ot ters than in dogs.