Why Is My Cat Drinking And Peeing SO Much?

Posted 08.24.17 by Amanda Shoemake, DVM

Excessive drinking, or polydipsia, and excessive urinating, or polyuria, are common presentations in any age dog or cat, but are especially prevalent in our older cat populations.  People most commonly think these are related to the urinary tract and must mean a urinary tract infection.  Sometimes that’s the case, especially because our aging pets are more prone to urinary tract infections.  But often, these are clinical signs of other disease.

Diabetes Mellitus is one of these diseases.  Often, the first sign an owner notices in a diabetic cat, is having to change the litter box more frequently and fill the water bowl more often.  Other signs may include weight loss, sticky urine, or loss of appetite.  Diabetes is a treatable disease in cats, but often requires special food, insulin injections and frequent blood and urinalysis monitoring.

Another disease that causes polyuria and polydipsia in aging cats is kidney failure.  The kidneys are very important for both conserving and removing excess water (depending on what the body needs at the time), filtering toxins from the body, balancing critical electrolytes and important nutrients, regulating blood pressure, conserving protein, and assisting in red blood cell formation. As the kidneys age, they may become increasingly insufficient at these tasks.  When this occurs, often the first noticeable signs in a cat are increases in drinking and urinating. As kidney disease progresses into failure, cats will lose weight, often have frequent vomiting, and may even stop eating altogether.  While kidney disease/failure is not curable, we can often manage it and allow the pet to continue to have a good quality of life for quite some time.

Hyperthyroidism, a disease caused by the over-production of thyroid hormone, is frequently diagnosed in older cats. The most common presenting complaint in a hyperthyroid patient is weight loss in the face of an increased appetite.  However, this disease also increases thirst, causing polydipsia and polyuria.  Hyperthyroidism is another disease that is very treatable and actually has several different treatment options, ranging from daily oral or topical medication, to one time radioactive iodine treatments.

Excessive drinking and urination is most often present due to some type of underlying disease, though there can also be behavioral reasons as well.  It is always important to have your cat checked by your Veterinarian to determine the reason for these signs and determine the best treatment plan for your furry friend.