Many alpaca breeders routinely drench their animals at shearing without performing faecal egg counts on the herd. Animals should be drenched with an effective drench at shearing if (a) faecal egg counts indicate high worm burdens and pastures are still green and harbouring worm larvae (suppressive drench) OR (b) faecal egg counts are greater than zero eggs per gram and pastures have dried off so pastures are not harbouring worm larvae (strategic drench or “first summer drench”). Speak to your veterinarian and parasitology lab about when and with what to drench your alpacas in your district.
Strategic drench = a worm drench administered when there are adult worms inside your alpacas but few worm larvae on the pasture (dry conditions, very cold conditions or very hot conditions). This type of drench vastly reduces parasites on your farm as you are using environmental conditions in conjunction with a worm treatment strategically.
Suppressive drench = a worm drench administered when there are high numbers of adult worms inside your alpacas and many worm larvae on the pasture (wet and mild conditions). This type of drench reduces production losses/deaths in your animals and continued monitoring of faecal egg counts is warranted every 4-6 weeks as animals are continually picking worm larvae up off the pasture when grazing.
If the efficacy of your drench is unknown, consider performing a faecal egg count reduction test (FECRT) to check efficacy of multiple classes of drench OR perform a faecal egg count 10-14 days after drenching to check there has been more than a 95% reduction in faecal egg output.