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Cat Drinking and Peeing A Lot? Not Normal, Get Him Checked Out!

Cats Excessively Drinking Not Normal

Cats are notoriously very cryptic about pain and illness. They are so tough and so determined to not show weakness that their health needs often go under the radar until illness or pain becomes unbearable and is by then often too advanced to successfully treat.  There is one sign, however, that cat owners can fairly easily pay attention to that is a common sign of illness in cats: excessive drinking and urination.

Most people who have owned cats have noted that cats are not big drinkers of water.  Descended from desert creatures, they possess an uncanny ability to concentrate their urine and retain hydration and subsequently drink very little when compared to dogs and people pound for pound.  Therefore, when they start drinking and urinating excessive (known in veterinary medical jargon as polyuria/polydypsia, aka, PU/PD), please know that this is almost never normal.

Diseases that PU/PD commonly indicate make the feline sick at least, can be deadly at worst, and include:


Diabetes in cats commonly (but not always) occurs in cats that are either obese or were at one time obese and are dropping rapid amounts of weight while they visit the water bowl and litter box in an unprecedented fashion.  Diabetes results from either an inability of the islet cells of the pancreas to secrete sufficient insulin to trigger the cells to take up glucose absorbed in the diet, or, the insulin receptors of the cells have become refractory to insulin (called insulin resistance).

95% of cats that are diabetic are Type II, non-insulin dependent.  This means that diet and lifestyle, not genetics, got them there.  This does not mean that they do not need insulin injections but it does mean that with insulin regulation, proper diet and weight control, there may be a day that the kitty many not require insulin administration.

Left untreated, diabetes can lead to peripheral vascular disease, kidney failure, neurological disease and a life threatening metabolic crisis known as diabetic ketoacidosis.

See Diabetes for more details.

Kidney Failure

The kidneys fulfill an important blood filtration role in the body, while also maintaining hydration balance by diluting the urine to eliminate excess body water, and concentrating the urine to preserve body water.  Cats in early kidney disease often show no signs and disease reveals itself incidentally in routine senior blood work or pre-dental screening blood work.  In more advanced stages of disease, the kidneys lose their ability to concentrate urine and retain hydration, so cats commonly begin to drink and urinate excessively.

As disease progresses and toxins continue to build in the kidneys, feline kidney failure patients lose weight, appetite diminishes, some start vomiting, and ulcers of the mouth and stomach occur.  Depending on the stage of disease, kidney failure is treatable with fluids, B-complex vitamin injections, and prescription kidney sparing diets.

See Kidney Failure for more details.


As cats age, they commonly develop tumors on one or both thyroid glands.  While the vast majority of these tumors are not cancerous, the are functional and lead to excess secretion of thyroid hormone.  Cats with hyperthyroidism commonly lose weight despite a normal or even excessive appetite, are commonly unusually active for their advanced age, commonly vocalize, and drink and urinate more frequently than typical.

In the short term, cats with hyperthyroidism experience anxiousness, cardiovascular stress, stress on the kidneys, and make them clot prone.  Left untreated, hyperthyroidism can lead to heart failure, kidney failure, and dangerous clot formations.  Hyperthyroidism is treated either by iodine free diet (Hills Y/D), treatment with methimazole, or radioactive iodine therapy.

See Hyperthyroidism for more details.

The bottom line of this article is: if your cat is drinking and urinating more than usual, get him seen ASAP, as there is likely something seriously wrong.

Dr. Roger Welton is a practicing veterinarian and well regarded media personality throughout a number of subjects and platforms.  In addition to being passionate about integrative veterinary medicine for which he is a nationally renowned expert, Dr. Welton was also an accomplished college lacrosse player and remains to this day very involved in the sport.  He is president of Maybeck Animal Hospital , runs the successful veterinary/animal health  blogs Web-DVM and Dr. Roger’s Holistic Veterinary Care, and fulfills his passion for lacrosse through his lacrosse and sport blog, The Creator’s Game.

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