When do I need to worm my sheep?
This very much depends on the stocking density of the sheep on the land, whether the land has had sheep on in the past, and where the sheep came from to begin with.
If there is a low stocking density on land that has not had sheep on for a while then the sheep should not have a large worm burden. Many keepers in this situation would then worm at tupping (Oct/Nov) and then again about a month after lambing (May/June). If sheep have dirty bottoms and/or are coughing this is a sure sign of worms and a further worming is recommended. Lambs generally need worming more frequently.