Clinical and pathological insights into severe acute copper poisoning in sheep with extreme liver and kidney accumulation

Abstract This study investigated acute copper poisoning in sheep, resulting in 42 deaths out of 170 (24.7%) within 1 week. The owner had an orchard near the pasture that was sprayed with copper sulphate for pest control 2 months earlier. Although the sheep were usually kept away from this area, the gates were opened during rain for shelter, allowing some to enter, drink rainwater, and eat fallen leaves and grass. Two weeks later, clinical signs emerged, including tachycardia, dyspnoea, jaundice and anorexia. Despite relocating the sheep to another pasture, fatalities continued. Two sheep were brought in for diagnosis; postmortem examination revealed severe jaundice, reddish urine and hepatomegaly, while histopathology indicated liver congestion and kidney tubular necrosis. Copper analysis showed concentrations of 859.8 mg/kg wet matter in the liver and 232.2 mg/kg in the kidneys. The study highlights the risks of copper sulphate‐treated grazing areas after rainfall, leading to acute copper poisoning in sheep.