Sheep Copper Toxicity Prevention Welfare

Copper toxicity in sheep is a serious and often fatal welfare problem caused by supplementation errors, dietary changes, or breed susceptibility, requiring careful management to prevent.

Key Facts

Sheep have a narrow copper tolerance - much narrower than cattle - making toxicity a genuine risk
Breeds including Texel, Suffolk, and North Ronaldsay are particularly susceptible
Copper accumulates in the liver before sudden haemolytic crisis - the toxic threshold can be exceeded with no warning signs
Common causes include using cattle feed for sheep, copper-rich pastures, and oversupplementation
Treatment with ammonium tetrathiomolybdate can be effective if administered before full haemolytic crisis

Welfare Considerations

Copper toxicity causes haemolytic crisis with severe jaundice, haemoglobinuria, and rapid deterioration. Affected sheep suffer intensely and mortality is high. Prevention requires rigorous attention to copper content in all feeds and supplements, breed-specific knowledge, and monitoring of dietary copper load. Farmers must understand that well-intentioned supplementation can kill sheep if breed sensitivities are not respected.

What You Can Do

Never give sheep feeds or supplements intended for cattle
Monitor dietary copper content when making pasture, forage, or supplement changes
Learn breed-specific copper sensitivities before introducing new sheep breeds
Support research into better copper assay methods and supplementation guidelines for sheep