Abstract
In February 2013, several 65- to 75-day-old pigs exhibited convulsive seizures and astasia, and then died during a 4-day period after being moved to pig-fattening farm A. This occurred on three successive occasions. In September of the same year, at commercial farrow-to-finish pig farm B, ten 50-day-old pigs exhibited similar symptoms and died soon after being moved to a piglet house. Autopsies were performed on these cases at both farms, but no remarkable findings were observed. A pathological examination revealed an infiltration of eosinophils into the cerebral parenchyma and meninges and stratified necrosis in the cerebral cortex. A raw chemical inspection of the serum revealed increased sodium ion density and chloride ion density. These cases were diagnosed as sodium poisoning in pigs. Cases of increased sodium ion density with a significant rise in osmotic pressure were seen, which was associated with an increase in the BUN level. An epidemiology investigation showed poor feed-water quality control in the drinking equipment of both farms, and an insufficient amount of drinking water is considered to have been the cause of the pigs' sodium poisoning. The measurement of osmotic pressure in serum thus appears to be useful when determining the degree of dehydration due to sodium poisoning in pigs.
