Drench tests (post- dosing faecal egg counts) give a quick indication of the efficacy of an anthelmintic (wormer) from samples of 10 sheep after treatment. The time after treatment depends on the wormer used, and would be most meaningful if used in conjunction with the information recorded from a pre- treatment FEC. 1-BZ (white) 10-14 days, 2-LV (yellow) 5-7 days & 3-ML (clear) 14-16 days.
Samples should be fresh when collected (less than one hour old) and kept cool in an airtight bag before being received at the laboratory within 48 hours. Each test contains individual samples from at least 10 animals. Mob samples can be taken either by gathering them in the corner of a field for a few minutes and picking up samples as they move, or carrying the bags when out herding taking samples as the lambs get up.