FEC Equine worm egg counts? ----What do the results mean?
When you see the symbol < followed by a number such as <200 EPG this means that the level of worm eggs found is less than 200 per gram.
If the count is less than 200 EPG then it is a Low count and would suggest that your worming measures are working which would then suggest delaying the next treatment.
If the count is between 200 EPG and 1200 EPG it is a Medium count which would mean that that particular horse needs treatment and perhaps the overall strategy needs some attention.
If the count is more than 1200 EPG it is a High count that horse should be treated without haste and the management and worming strategy and planning will need considerable attention.
Results cannot show encysted stages of redworm potentially the most harmful stage of the redworm parasite. Horses can have burdens in the order of several million encysted larvae yet show a negative or low (<100 epg) FWEC (Dowdall et al. 2002, Veterinary Parasitology, 106, 225-42).
Pinworms are not reliably detected in standard egg counts because they don't consistently lay eggs as part of their life-cycle and bots are not identified in FECs either as Bots will rarely appear in a dung sample.