Signs of deficiency include anemia, brittle or fragile bones, loss of hair or wool pigmentation and poor wool growth. Toxicity can occur at levels above 25 ppm. If Mo intakes exceed 10 ppm, Cu deficiency may occur on diets that would normally be adequate. In these situations, chronic Cu poisoning may result from excessive Cu intakes or from low intakes of Mo, S, zinc, calcium or following liver damage. Stresses, such as weather, environment, poor nutrition, transportation and handling, can also cause the liver cells to die and release the stored copper into the bloodstream.
Affected sheep are lethargic and anemic.
They may grind their teeth incessantly and experience extreme thirst. Membranes are very pale and may appear yellow, as jaundice sets in. Urine is a bloody color. Death usually occurs 1 to 2 days after the onset of clinical symptoms. At post-mortem, tissues are pale to dark yellow and the kidneys are a very dark color.