Copper toxicity is a serious and often fatal condition in sheep caused by their unique sensitivity to copper accumulation, which can be triggered by excessive dietary supplementation or high-copper feeds.
Copper toxicity causes a particularly cruel welfare trajectory: months of silent accumulation followed by sudden, catastrophic hemolytic crisis. The crisis phase is characterized by extreme distress, severe anemia, organ failure, and rapid deterioration. Animals that survive the initial crisis often die within days from kidney failure. Prevention is straightforward — ensuring sheep never receive copper-supplemented feeds intended for other species, and monitoring pasture and mineral programs — but the silent accumulation phase means the problem is often not recognized until the crisis occurs. Education of farmers and veterinarians about species-specific copper sensitivity is the most important welfare intervention.