Prolonged blood urea elevation observed in the beagle after feeding

In the beagle, a meal of various standard dog diets (100–500 g) produces a significant elevation of blood urea nitrogen (BUN) which lasts 10–18 hours; blood sugar levels are little changed during this time. Particularly when beagles receive the bulk of their daily protein intake at one meal, BUN levels can rise to values often considered indicative of renal insufficiency. Female beagles, even when they consume slightly more food than males (relative to their size), tend to show a slightly smaller elevation of BUN. The importance is stressed, in toxicity testing and veterinary practice, of taking blood samples for BUN determinations only from dogs which have been fasted long enough since their last meal (10–18 hours) for the postprandial elevation of BUN to have passed.