What are sources for chronic copper toxicosis in sheep?

• A. Water in mining areas
• B. Soil contamination only
• C. Pesticide residues in grain
• D. Feed additives, soils, and plants

Answer: (D)

Chronic copper toxicosis in sheep results from long-term dietary copper accumulation, with the liver acting as a storage reservoir that can be released into the bloodstream under stress, causing hemolysis and pale mucous membranes.

The best answer recognizes that copper comes from multiple dietary sources: feed additives (copper supplements in concentrates or rations), soils (soil copper affects plants and can be ingested by grazing animals), and the plants themselves (forages grown in copper-rich soils or naturally high-copper plants). This broad combination explains how sheep continuously accumulate copper over time.

Water in mining areas could contribute in some cases, but it’s not the primary, encompassing source. Soil contamination alone doesn’t account for copper entering the diet through forage and feed, and pesticide residues in grain are not a source of copper.