Indirect effects of soil and water on animal health.

Some variations in animal health among geographic areas are associated with variations in soils, water supplies or soil parent materials. Geochemical bases for health problems arising from essential nutrient element deficiencies or from toxic levels or imbalances of several elements are widely recognized. Less attention has been directed to the possibilities of geochemical influences upon regional differences in health resulting from pathogens, parasites, mycotoxins and poisonous plants. This review is an effort to collect and interpret such evidence as has been published on the subject since Louis Pasteur's original observation associating soil character and probability of anthrax.