Fecal moisture can have a significant effect on the worm egg count (eggs per gram of feces) using standard techniques.
Vets and others experienced with diagnosing gastro-intestinal parasitism will often make a mental adjustment of FEC based on fecal consistency. For example, "This sheep has an epg of 700, but it's scouring, so the 'real' egg count might be 1500-2000."
Because of possible (significant) effects on decision points for treatment, estimated breeding values, and categorizing anthelmintics in fecal egg count reduction tests, there is a good case for including a fecal consistency score and moisture adjusted worm egg count as a standard practice in parasitology labs.
Source: WormMail [http://www.wormboss.com.au]
Note: There will be an all-day fecal egg counting workshop at the Western Maryland Research & Education Center on Saturday, June 16, 2007. Further information will be posted at a later date to this blog and to the Maryland Small Ruminant web site.