Salt Tolerance and Salt Poisoning of Swine

COMMON SALT is recognized as one of the chemical substances required in the diet of animals; hence it is good husbandry to include a supply in the rations of livestock. The quantitative requirements vary with the species. Those for swine are regarded as among the lowest. That excessive aniounts may be harmful to the extent of being toxic is not at all surprising, since there are recognized limits beyond which various nutritive essentials become a burden, or even toxic, to the animal body. Much of the science of animal nutrition is built around the proper proportioning and balancing of the essential elements of the diet. "Salt poisoning" is the term frequently used to characterize certain forms of poisoning, often fatal, in swine, which are generally attributed to an excessive intake of sodium chloride. The true cause, particularly the conditions under which severe poisoning may result, remains obscure. Various reports have listed a number of gross symptoms as characterizing the condition, including extreme nervousness, frothing at the mouth, convulsions, paralysis, diarrhea, vomiting, loss of appetite, extrenie thirst, blindness, and finally death. As evidence of the causative agent, case histories have frequently pointed to the consumption of large amounts of salt, especially in the form of brine, by