Transient, traumatically induced, central diabetes insipidus in a dog.

A 9-year-old mixed-breed dog was evaluated for dental malocclusion secondary to mandibular fractures that had been repaired after the dog had been hit by a car. The dog had hypernatremia, high plasma osmolality, low urine osmolality, and hyposthenuria with adequate fluid administration. Skull radiography revealed a fracture line at approximately the level of the pituitary fossa. Administration of exogenous vasopressin resulted in an increase in urine specific gravity and urine osmolality, a decrease in serum osmolality, and a normalization of serum sodium concentrations. Follow-up evaluation revealed a reduction in the frequency of exogenous treatment with vasopressin over the ensuing months, indicating transient, traumatically induced, central diabetes insipidus.