Mixed cryoglobulinaemia in a rhesus macaque (Macaca mulatta).

We report cryoglobulinaemia (CG) in a rhesus macaque whose serum sample was gel-like at <37°C and resolubilised upon warming. Mixed CG was diagnosed using serum protein electrophoresis and serum immunofixation electrophoresis. Renal damage and arthrophyma were observed during necropsy. This is the first report of CG in a non-human primate.