Reference intervals for selected blood and urinary parameters related to renal function in clinically healthy ferrets (Mustela putorius furo)

Diagnosis of chronic kidney disease can be challenging in ferrets. Physiological creatinine values are lower than in dogs and cats and marked elevations may only be detected in advanced disease. In canine and feline patients, specific staging, and treatment guidelines are available, based on serum creatinine, symmetric dimethylarginine (SDMA) levels, presence of proteinuria, and blood pressure measurement. No such guidelines exist for ferrets, and there is a lack of data concerning certain laboratory parameters. Blood and urine samples were taken from 60 clinically healthy pet ferrets to establish species-specific reference intervals for serum SDMA and urine protein/creatinine ratio (UPC ratio). Liquid-chromatography tandem mass spectrometry (HPLC-MS) was used for determination of serum SDMA, a colorimetric spectrophotometric method for urinary protein and an enzymatic method for urine creatinine. The calculated reference interval for serum SDMA (2.78–7.66 µg/dL) was found to be lower than in dogs and cats, while the UPC ratio is similar to dogs (<0.5).