Partial deficiency of antidiuretic hormone in a cat

Marked polydipsia and polyuria developed subsequent to trauma in a 1 1/2-year-old male Abyssinian cat. Diabetes insipidus was suspected, inasmuch as intramuscualr vasopressin administration resulted in amelioration of polydipsia and polyuria. However, hypertonic (3%) saline solution given intravneously resulted in anuria, an indication of antidiuretic hormone activity. Polyuria and polydipsia were abolished by oral chlorpropamide therapy, which was indirect evidence for partial deficiency of antidiuretic hormone.