Sheep Pregnancy Toxaemia: Prevention and Flock Welfare

Pregnancy toxaemia (twin lamb disease) is a life-threatening metabolic condition in ewes carrying multiple lambs, causing significant welfare problems in sheep flocks.

Key Facts

Pregnancy toxaemia arises from negative energy balance in late pregnancy, when fetal glucose demand exceeds maternal supply.
Ewes carrying twins or triplets are at highest risk, particularly in the final 6 weeks of pregnancy.
Mortality rates without treatment can reach 80%; even treated ewes may die or lose lambs.
Signs include dullness, tooth grinding, blindness, muscle twitching, and recumbency.
Flock-level incidence is strongly linked to body condition score at tupping — thin ewes (BCS <2.5) have insufficient energy reserves.

Welfare Considerations

Pregnancy toxaemia causes profound suffering including metabolic encephalopathy, hepatic fat infiltration, and organ failure if untreated. Affected ewes are unable to stand or eat and experience significant pain. Prevention is substantially more effective than treatment and requires systematic flock management: body condition scoring all ewes at tupping (target BCS 3-3.5), scanning to identify multiple-bearing ewes, and providing increased nutrition from 8 weeks pre-lambing. Treatment with propylene glycol, glucose infusions, and corticosteroids can be effective if initiated early. Welfare improvement programmes like the AHDB BETTER Returns Programme include pregnancy toxaemia prevention as a core module for UK sheep farmers.

What You Can Do

Body condition score all ewes at tupping, weaning, and 8 weeks before lambing.
Ultrasound scan all pregnant ewes to identify multiple-bearing animals for preferential feeding.
Increase concentrate supplementation for twin and triplet-bearing ewes from 6-8 weeks pre-lambing.
Learn to recognise early signs of pregnancy toxaemia for prompt veterinary treatment.
Discuss lambing management protocols with your vet and consult AHDB's sheep welfare resources.