In cases
of pituitary tumors causing hyperadrenocorticism that are medically managed, the treatment needs monitoring and life expectancy is variable from days to ten years but averaging less than three years.
The growth rates
of pituitary tumors in dogs and cats vary greatly, and the rate at which symptoms progress depends on tumor type.
The second most common
type of pituitary tumor is not functional in dogs, but in cats, secondary effects include diabetes mellitus, degenerative arthritis and kidney disease.
A large dose of dexamethasone will suppress the pituitary's ACTH production despite the
existence of a pituitary tumor; however, adrenal tumors will continue to pump out cortisol since they are not ACTH dependent.