Water intoxication in adult cattle.

Water intoxication is a common disorder in calves and is usually characterized by transient hemoglobinuria. In contrast, the condition is very rare in adult cattle, with few reports on naturally occurring cases. In the present report, four female Japanese Black cattle, aged 16-25 months, showed neurological signs when they drank water following a water outage. Hemoglobinuria was not grossly observed, while severe hyponatremia was revealed by laboratory tests. Autopsy indicated cerebral edema with accumulation of serous fluid in expanded Virchow-Robin spaces. These results indicate the possibility of water intoxication associated with cerebral edema due to severe dilutional hyponatremia in adult cattle.