The Creatinine Level Of Your Dog And Cat's Urine And Why It Is Important













Ron Hines DVM PhD

To see what normal blood and urine values are, go here

For an explanation of causes of most abnormal blood and urine tests, go here

To see how tests are grouped, go here

Creatinine In Your Pet’s Urine

The creatinine in your pet’s urine originates from the same sources (chiefly its muscles) as the creatinine in your pet’s blood.

The presence of creatinine in its urine does not, in itself, tell your veterinarian very much. Its chief value is that unlike many other urine components (such as water, cortisol and protein) normal kidneys excrete creatinine in a rather steady amount throughout the day. So the creatinine level in your pet’s urine is often compared to other urine constituents to decide if those other constituent levels are higher or lower than they ought to be. Creatinine can be used as a standard benchmark (or ratio) to which other urine components are compared. Those other ingredients tend to fluctuate more with changes in your pet's urine concentration throughout the day rather than their true blood levels. Several urine assays - like cortisol:creatinine rule-out tests for Cushing's disease (or illegal drug screening in humans) rely on the kidney's rather steady rate of creatinine excretion.



When your veterinarian is attempting to evaluate the condition of your pet’s kidneys, the he/she is considerably more likely to examine your pet’s blood creatinine level than its urine creatinine level and look at other urine parameters like specific gravity or albumen content.

Pets receiving certain antibiotics (eg cephalosporins, gentamycin, trimethoprim-sulfa) or antacids (cimetidine) can give incorrect urine creatinine and creatinine ratios.