Evaluation of brain chloride determinations in the diagnosis of water deprivation/sodium salt intoxication in pigs

In a series of pig brains submitted from field cases where water deprivation/sodium salt intoxication was suspected, histopathological examinations and chloride determinations were performed. A poor correlation was found between brain chloride concentration and neuropathology. The ranges of chloride concentrations found were similar for brains showing the encephalopathy of water deprivation/sodium salt intoxication, brains with other neuropathological diagnoses and brains without significant histopathological lesions. A close correlation was found between brain sodium and chloride in a further similar series, suggesting that determinations of sodium would not be more helpful diagnostically than determinations of chloride. A wide range of brain chloride values was also found in a group of healthy slaughtered pigs but the significance of this was not apparent. Brain chloride determinations have little value in the diagnosis of water deprivation/sodium salt intoxication in pigs, especially when performed in isolation without concurrent neuropathology and an adequate clinical history.