Assessment of urinary N-acetyl-β-D-glucosaminidase activity in geriatric cats with variable plasma creatinine concentrations with and without azotemia

N-acetyl-beta-D-glucosaminidase activity can be quantified in feline urine by use of a non-automated colorimetric technique. However, data should be interpreted cautiously because of high interassay CVs. The NAG index in cats with CKD may be indicative of ongoing lysosomal activity rather than active proximal tubular cell damage.