Diabetes insipidus in a cow.

Diabetes insipidus was diagnosed in a 6-year-old Holstein-Friesian cow with a history of recurrent fever, ketosis, lymphadenopathy, and inappetence. The diagnosis was based on the clinical findings, response to exogenous vasopressin, and lack of urine concentration in a water deprivation test. The disease gradually regressed over a period of 1 year and did not recur.