Suspected myelinolysis following rapid correction of hyponatremia in a dog.

A dog developed signs of neurological dysfunction five days after rapid correction of severe electrolyte derangements, including hyponatremia, caused by gastrointestinal parasitism (i.e., trichuriasis). History, laboratory findings, and onset of neurological signs following correction of hyponatremia led to a diagnosis of myelinolysis. Myelinolysis is a noninflammatory, demyelinating brain disease caused by sudden, upward osmotic shifts in central nervous system plasma, often a result of rapid correction of chronic hyponatremia. The pathogenesis is complex, but recovery is possible. Iatrogenic damage due to myelinolysis can be avoided by adherence to therapeutic guidelines for correction of chronic hyponatremia.