At weaning time, don’t forget to perform an individual faecal egg count (FEC) on each of your alpaca weaners BEFORE drenching them, and again 12 days later.
- The first, pre-drench, FEC tells you how wormy that individual is – genetically, some will be wormier than others. Useful as a tool for future selection against worms? Possibly.
- The second, post-drench, FEC tells you the efficacy of the drench used. An effective drench must reduce the original count by 95%. E.g. If the first, pre-drench, FEC was 450 eggs per gram (epg) and the second, post-drench FEC was 50 epg, then the drench was [100 – (50/450 x 100)] = 89% effective. This is not regarded as an effective drench and another product from another drench group should be used, and another FEC performed 12 days later.