High serum and urine lysozyme levels in a dog with acute myeloid leukemia.

A 2-year-old, female German Shepherd Dog with facial nerve paralysis was diagnosed with acute myelomonocytic leukemia based on clinical, cytologic, and immunologic findings. Proteinuria (urine proteincreatinine ratio = 1.5) occurred in the absence of renal failure. Qualitative assessment of proteinuria by sodium dodecyl sulfate-agarose gel electrophoresis revealed a broad band with a molecular weight of approximately 15 kDa that was compatible with lysozyme (LZM). A diagnosis of tubular proteinuria was made, and a chemical evaluation of LZM in serum and urine samples was performed using a turbidimetric assay. The LZM concentrations were 24.5 mg/l (reference interval: 2.5-8.0 mg/l) and 274.5 mg/l (reference interval: <2 mg/l) in serum and urine, respectively.