Fecal Sedimentation

Indications for performing this test:  This test is primarily used to identify ova of internal parasites that do not float well on fecal flotation.  Specifically, fluke eggs are typically identified by this test.  Fecal sedimentation can also be used to detect the presence of sand in an animal's feces.

The Test:  This is a simple procedure that allows for all of the debris and eggs present in the fecal sample to simply settle at the bottom.  Thoroughly mix one gram of feces with approximately 40 ml of water. Next, either pour the mixture into a centrifuge tube and centrifuge for five minutes or allow to settle for at least twenty minutes.  Then remove the supernatant fluid and collect a small amount of the sedimentation at the bottom of the tube with a pipette.  This sediment may be examined under a microscope slide.  Alternatively, a device such as the Fluke Finder, which filters eggs from the fecal slurry, may be used in the search for ova.

Above:  The "Fluke Finder". It is used in fecal sedimentation examinations to aid in the diagnosis of fluke infections.  The two filters in the tube remove the debris but allow the fluke eggs to accumulate below. Right:  Nanophyetus salmincola is the fluke responsible for transmitting Salmon poisoning disease in dogs.  While the fluke itself is nonpathogenic, the neorickettsia it carries is very pathogenic and is often fatal if not treated promptly.   The distinctive operculated fluke eggs are typical of Nanophyetus.		Above:  Adult Fascioloides magna flukes.  These flukes were among several hundred others that were collected from an adult elk.  They appeared to be causing little damage despite their large size.  The largest fluke pictures above measures 2.5 inches in length.