Higher Risk

Yes, every animal is treated when worming a group of lambs.

Although it may seem counter-intuitive, it is better not to try to eliminate worms from your sheep altogether, but rather, to allow some worms to survive. This enables these worms to pass their genetics down to the next generation, delaying the onset of resistance. In any group of lambs, the heaviest and fastest growing ones are unlikely to need worming. Aim to leave at least 10% of the group untreated every time you dose. This advice only applies to roundworms. If treating for any other parasite it is usually best to treat the whole group. Discuss your lamb worming protocol with your vet as part of your flock health plan.

Typically, 20% of lambs in a group carry 80% of the worm burden