Are BUN and Creatinine sufficient for evaluating renal function?
BUN and creatinine help assess renal function, so they are necessary but not sufficient. Creatinine is almost entirely excreted solely by the kidneys and increases with impaired function. BUN is less reliable. It is possible to have a patient with values within a laboratorys reported reference intervals, but still be abnormal. For instance, if the pet started with a much lower BUN/Creatinine (which you didnt know about), and has begun to increase these variables at the time of assessment, it is possible that renal dysfunction may be undetected at the first evaluation. Any patients with BUN or creatinine at the high end of the laboratorys reference range should be retested in 24-48 hrs to determine if the initial values are the front end of an acute renal problem, or simply normal for that patient. This can be omitted if very recent wellness testing confirms that these high-normal values are indeed normal for that animal. When retesting, obtain samples at the same time of day to minimiz
