i'm a human nurse, but i know a little about BUN. (well i think i should
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this is for humans, but i'm not sure about yorkies
The BUN level, usually with tests for creatinine, is used to evaluate kidney function and to monitor patients with kidney failure or those receiving dialysis therapy
High BUN levels suggest impaired kidney function. This may be due to acute or chronic kidney disease. However, there are many things besides kidney disease that can affect BUN levels such as decreased blood flow to the kidneys as in congestive heart failure, shock, stress, recent heart attack or severe burns; conditions that cause obstruction of urine flow; or dehydration.
Creatinine is a protein produced by muscle and released into the blood. The amount produced is relatively stable in a given person. The creatinine level in the serum is therefore determined by the rate it is being removed, which is roughly a measure of kidney function. If kidney function falls (say a kidney is removed to donate to a relative), the creatinine level will rise.
hope that helps.. a little
