Cytology

Joints are lubricated by synovial fluid, produced by specialized lining cells, called synoviocytes. The cells produce hyaluronic acid as well as other constituents of synovial fluid, including glycosaminoglycans. These proteins impart viscosity to the fluid, which is subjectively assessed as part of synovial fluid analysis. A small volume of synovial fluid can normally be aspirated

Fluid cannot normally be aspirated from the abdomen in small animals (dogs, cats) but small amounts can be collected from the abdomen of large animals (horses, ruminants, camelids). Thus, interpretation of peritoneal fluid results includes the concept of “normal values” for the latter species, whereas any abdominal fluid that has accumulated is abnormal in small

Excess fluid can accumulate in body cavities from multiple causes.  Characterizing an effusion by its cytologic properties is an important step in diagnosing the cause of the effusion. In dogs and cats, the volume of fluid within the peritoneal, pleural and pericardial space is quite small (generally less than 10ml) and fluid cannot normally be