Differential Diagnosis: Increased & Decreased Creatinine

Following are differential diagnoses, listed in order of likelihood, for patients presented with increased or decreased creatinine.

Increased Creatinine

Of note, any increase in creatinine should be interpreted in conjunction with urine specific gravity.

• Renal disease

• Dehydration

• Postrenal obstruction or leakage

• Breed predisposition

  • Sighthounds (eg, greyhounds [due to increased muscle mass])

  • Birman cats

  • Siberian and, to a lesser extent, Siamese and Somali cats

Decreased Creatinine

• Decreased muscle mass due to starvation or cachexia

• Increased glomerular filtration rate (eg, overhydration, portosystemic shunts, any cause of severe polyuria/polydipsia, pregnancy)