Blood urea nitrogen (BUN)
of blood urea nitrogen (BUN) concentrations may be caused by many different things
including pre-renal and post-renal factors and should not be considered diagnostic
of primary renal disease in all cases. Addiblood biochemistry and urinalysis are
necessary to evaluate fully the cause of high BUN concentrations. To eliminate dietary
factors BUN should be performed on blood collected after 12 hours starvation.
Normal Range: 5-11 mmol/l
Normal range: 2.5-7 mmol/l
In old animals undergoing routine screening a high BUN
may indicate the presence of:
chronic renal failure or other renal disease
Cats are obligate carnivores and have liver enzyme systems
for protein metabolism which do not down-regulate in the presence of reduced prointake
in the diet. As a consequence of this, and of the large number of clinical conditions
that can lead to catabolism, a high BUN, muscle wastage and weight loss are common
features in old cats. In fact, almost any major organ system disorder is accompanied
by severe catabolism and loss of lean body mass in the cat.
Low BUN concentrations are seen in animals on low protein
rations or in the presence of liver failure or acquired portosystemic shunts.