Salt poisoning occurs commonly in pigs by excessive intake of sodium chloride or by a period water deprivation for followed by free access to water. The objective of this work is to aggregate data from cases of salt poisoning, combining existing data in the literature and describe the main clinical and pathological features observed. We reviewed five outbreaks, one of which was carefully monitored. In three of them the intake of sodium chloride had been determined. Clinical signs were basically seizures with the lateral decubitus with paddling movements. Circling was observed in some cases. Sodium determination in muscle of and liver fragments, serum, cerebrospinal fluid and aqueous humor showed increased concentrations of this ion. There was eosinopenia characterizing increased recruitment eosinophils from the circulation into the brain. In all outbreaks eosinophil infiltration was observed in the meninges and the Virchow-Robin space of the cerebral cortex. Cortical laminar necrosis was more pronounced in the brain of pigs from one of the outbreaks in which animals were sick for six days. The combination of these two lesions characterizes the disease. The changes observed result from high concentrations of sodium in the brain causing cause edema that leads to increased intracranial pressure and decreased perfusion to the brain tissue causing diffuse ischemia and neuronal necrosis, with consequent malacia.
Swine diseases; sodium concentration; eosinopenia; eosinophilic meningoencephalitis; neuronal necrosis
