The effect of copper deficiency on the resistance of mice to infection with Pasteurella haemolytica.

Mice adjudged copper deficient on the basis of significantly decreased blood and tissue copper content and superoxide dismutase activity, but generally showing no clinical signs of deficiency, were infected intraperitoneally with Pasteurella haemolytica. In 3 separate experiments the LD50 for deficient animals was significantly depressed below that of copper-sufficient controls. Furthermore, in mice surviving challenge at doses near to the LD50, spleen weights were significantly increased and body temperatures depressed in the copper-deficient animals. These results indicate that subclinical copper deficiency in the mouse, is associated with an increased susceptibility to experimental infections with P. haemolytica.