Farmed Sheep Metabolic Disease and Welfare

Metabolic diseases in sheep including pregnancy toxaemia, hypocalcaemia and hypomagnesaemia cause significant preventable welfare harm around lambing.

Key Facts

Pregnancy toxaemia (twin lamb disease) occurs in ewes carrying multiple foetuses with inadequate nutrition
Clinical signs include depression, incoordination, blindness and death without treatment
Hypomagnesaemia (grass staggers) causes sudden collapse and tetanic convulsions
Hypocalcaemia in sheep causes similar signs to milk fever in cattle
Risk periods concentrate around late pregnancy and early lactation
Flock-level body condition scoring before breeding and late pregnancy identifies at-risk ewes
Dietary supplementation at critical periods prevents most metabolic disease
Periparturient ewes require close monitoring during the two weeks around lambing

Welfare Considerations

Metabolic diseases cause significant acute suffering in affected ewes. Pregnancy toxaemia causes progressive neurological deterioration with a prolonged course if untreated. Hypomagnesaemia causes sudden severe muscle spasms and rapid death. These conditions are largely preventable through targeted nutrition management, body condition scoring and strategic supplementation. High disease incidence on a flock indicates preventable welfare failures in nutrition management. Close monitoring at lambing allows early intervention before mild cases progress to severe welfare crises.

What You Can Do

Score all ewes' body condition at scanning and provide supplementary feeding to those below target
Implement magnesium supplementation through feed or water in the six weeks before lambing in high-risk areas
Monitor ewes closely in the two weeks around lambing and act immediately on abnormal behaviour
Work with your vet to develop a written metabolic disease prevention protocol
Record metabolic disease incidence as a welfare indicator and review management if cases exceed targets