Urea is the most important breakdown product of the protein metabolism in mammals. Serum levels depend on renal function and extrarenal factors (diet, increased protein degradation). Thus, creatinine should always be checked in parallel.
In cattle, the urea level serves mainly as an indicator for energy supply.
Urea is the most important renal parameter in aquatic and sea turtles and other aquatic reptile species, amphibians and fish.
