Fallibility of plasma urea and creatinine as indices of renal function in diarrhoeic calves treated with conventional or nutritional oral rehydration solutions.

Changes in plasma urea, creatinine and glomerular filtration rate (GFR) were measured in calves before and after development of diarrhoea and during treatment with a conventional (WHO-type) or a nutritional oral rehydration solution (ORS). Changes in urea and creatinine failed to represent the extent of pre-renal failure. The two ORSs differed in their impact on GFR with the nutritional ORS improving GFR whereas with the WHO-type solution it deteriorated further.