Faecal Egg Count (FEC) monitoring
What is a Faecal Egg Count (FEC)?
- An FEC counts the number of worm eggs in faeces (dung) and is used to monitor the worm burden in sheep.
- The results are presented as ‘eggs per gram’ (epg) of faeces
- The number of eggs is an indication of the number of adult worms in the gut of the sheep
FECs can be used to:
- Help determine the need to treat
- Test the efficacy of a treatment – see testing for resistance
- Give information on the amount of contamination going onto the pasture
To monitor FECs, you can use a suitably equipped and trained Veterinary practice, a commercial service or adopt a DIY approach using the FECPAK system. Samples should be fresh when collected (less than one hour old) and kept cool (not frozen) in an airtight container or plastic bag, before examination or delivery to the laboratory within 48 hours. If the faeces are too old some eggs will have hatched and the reported egg count will be an underestimate.
The sheep should be healthy and have had full access to pasture and/or feed before sampling otherwise the FEC will be difficult to interpret. For this reason, FECs should not be used as a diagnostic aid – they are used only for monitoring. when PGE is suspected in cases where sheep are profoundly ill. A worm count as part of a post-mortem examination is a much more appropriate way to estimate worm burden in such cases.
FEC Sampling (1)
Each test must be based on at least 10 individual samples
Samples must be taken at random. Do not try to pick and choose
Samples must be of fresh dung
FEC Sampling (2)
Mob samples can be taken either by gathering them in the corner of a field for a few minutes, then picking up samples when they move.
Carry pots/bags when out sheep herding and take a sample as lambs get up.
Interpretation of an FEC is quite complex and depends on a number of factors you should discuss with your vet or adviser. The figures below are ONLY a guide however for lambs on farms without a problem with Haemonchus contortus.
FEC (eggs per gram)