WHITLOCK worm egg counting - Calculations

The overall methods which utilise this information can estimate the degree of infestation in livestock and the efficacy of treatments.
 

STANDARD CALCULATIONS:

To determine the number of eggs per gram (epg) of faeces-

multiply the number of eggs of each type counted in the scanned area of the slide by

(Volume of faeces sample= weight of faeces sample)
(Measurement volume used may be only a part of the slide)

place 2g faeces in 2.5ml water (or 0.1% aqueous methylene blue) and 55.5ml flotation solution and measure or count in one chamber (0.3ml for the Whitlock McMaster)
- (for calculations for other Whitlock slides and different dilutions  see Universal , McMaster or Paracytometer):
-  (or click here to download a FREE Excel spreadsheet calculation program to get you started)
 

epg = #eggs  *  (2.5+2+55.5) / (2 * 1*0.3) = # * 100      where " * "   means  "multiply"
         (in other words, in this instance, multiply the number of eggs counted by 100 to give the epg.)
 

Reference:

Details about the techniques which use these slides may be found in the Section on Anthelmintic Resistance in Sheep (para 9.1 in particular) in Australian Standard Diagnostic Techniques for Animal Diseases. - ISBN 0 643 05243 7 636.0896075 developed through the Standing Committee on Agriculture and Resource Management, Animal Health Committee, [SCARM] Sub-committee on Animal Health Laboratory Standards [SCAHLS] and published on their behalf by CSIRO Information Services, Australia.

(Note that the recommended dilution is intended for the Whitlock Universal slide to give a simple Factor as above. Alternatives are permitted)

Available as 1.6Mb pdf on our website at  www.whitlock.com.au/slides/pdf/ASDT-AnthrlmResist-signed.pdf
and on the SCAHLS website at http://www.scahls.org.au/asdts/05-AnthelminiticResistanceinSheep.pdf

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