Increased thirst which is call polydypsia (PD) and increased urination which is called polyuria (PU) can be caused by many, many things. Sometimes PU/PD is the sign of something serious. Here is a list of the most common causes of increased thirst and urination I see in my practice. I have ranked them from most common to least common. If you observe a sudden change in your pet’s drinking or urinating, please seek medical attention right away.
-Urinary tract infections
-Drug induced. Steroids commonly cause increased thirst and appetite.
-Renal disease or failure due to primary renal disease, toxins, drugs, infections causing pylonephritis and leptospirosis
-Diet especially those that are formulated to treat or prevent stone formation.
-Hyperadrenocorticism which is also called Cushings Disease
-Hypoadrenalcorticism which is also called Addisons Disease
-Increased calcium associated with cancer
-Congenital abnormalities including renal dysplasia
Other rare causes of increased thirst and urination include:
-Renal medullary solute washout
-Idiopathic which means the cause is undetermined