Sodium in health and disease: a comparative review with emphasis on herbivores.

This review aims to illustrate the relationships between a number of basic and clinical aspects of sodium metabolism with special emphasis on herbivores, particularly ruminants. These animals provide a challenge to some traditional views based essentially on humans, dogs and laboratory rats reared on liberal sodium intakes. Detailed attention is focussed on two central issues; the magnitude of sodium requirement and the relative importance of the kidney and the gut in regulating body sodium. Both provide strong reasons to question accepted beliefs.