A quick drench check is a simple cost effective tool for keeping track of how each drench group is performing. A drench check consists of two worm egg counts. One worm egg count is performed before the drench and another 10-14 days post drenching. This is to check if the drench has reduced the worm egg count. A drench is considered effective when worm egg counts are reduced by 95% or more. Worm typing (larval culture and differentiation) should be carried out to determine which species of worms are resistant to the drench you have used.