Increased Urination and Thirst in Cats: What to Look Out For

Author: K. Marie Altoby K Marie Alto Updated 12 min read

Increased Urination and Thirst in Cats by Toe beans

Cats of all ages can be impacted by health problems, though they are much more common as they reach their senior years.

If you have a young kitty at home this post can still give you good information to know signs of illness to look for to know when an unplanned vet appointment might be warranted.

Pet parents with senior and geriatric kitties, this is a must read. There are many common ailments that impact older cats and adjustments to their diet or medication may be needed to address the issue.

One of the more common symptoms your feline companion may display when a health issue arises is increased urination and thirst.

While not in all cases, drinking more – and thus, peeing more – may be a side effect of illness, it's one that is often more obvious when it advances because it may lead to accidents.

In this post we’re going talk about the most common causes of increased thirst and urination, how they are treated, and we’ll also provide pointers for how to identify these changes.

As usual, don’t miss the educational videos, this post has 3!

Let’s get started.

Identifying Increased Thirst & Urination?

As our lives get busier, naturally we look for ways to automate everyday tasks. One tempting item, if you have the funds to afford one, is an automated litter box.

This might be an unpopular opinion, but I don’t recommend a self-cleaning litter box.

By a show of hands, who enjoys cleaning the litter box? I get it, they save time and sweep away the stinkies before they get time to stink up your home. That’s certainly a benefit I won’t argue. Where they fall short is their ability to tell you what’s being deposited into their waste bin.

Read More Cat Health Care Guides

As you may know, your cat’s litter box usage or lack thereof can tell you a lot about their health. Increased thirst and urination go hand in hand.

That is, if your cat is drinking more water than usual, they will also be peeing more than usual.

How Much Water Should My Cat Drink Daily?

Questions you may have at this point are how much is too much water or how much water should my cat drink daily? Well, this will depend on your cat’s weight as well as their diet.

Cats need to consume about 4 ounces of water per five pounds of lean body weight per day, so the average 10-pound cat should drink about one cup of water per day. It’s important to realize that cats that eat wet food, which can contain up to 80% water, may drink less, and cats that eat dry food usually take more of their daily water requirement in by drinking.” - Cornell University College of Veterinary Medicine

Now, unless you can monitor your cat’s water fountain 24/7, odds are you won’t be able to tell if your cat’s drinking habits have changed. Your best friend here is the litter box. Who would have thought anybody would consider a litter box as a good friend hmm?

Read More Cat Health Care Guides

As it turns out, any changes in water consumption will be date stamped in the litter box. Of course, so long as you follow a daily litter box cleaning routine. That’s the key.

Scooping the litterbox daily is the best way to identify changes in urine output. You can also keep an eye on the size of the clumps to see if there is a change in frequency, output, or both.

Case in Point: If you’re one of the many multi-cat households, you may notice the change while you’re scooping, but not know who’s responsible for the change. In this case I recommend, and have personally used, an inexpensive wireless camera. Set it up to view just the litter box and configure the settings to alert you when there is motion. If you’re home, you can immediately check the deposit and confirm the source.

A change in water intake may be difficult to identify if you use a bowl and freshen it daily, so keeping an eye on litter box output is going to be your best bet.

Read More Cat Health Care Guides

If you use a water fountain (and I highly recommend them), take note of how often you’re refilling the reservoir.

Did the refill rate change from once a week to not making it a full week? The change might be subtle at first, but the earlier you can recognize a change the better.

What Problems Can Cause Increased Thirst and Urination in Cats?

There is a whole variety of reasons that can lead to increased thirst and urination in cats. From a cat’s level of activity to behavioral issues such anxiety and stress, to the amount of time a cat spends indoors vs outdoors, to environmental/seasonal changes that could include excess heat to underlying health conditions.

Vet Treating a Cat With Diabetes Image by Toe Beans

The gamut of possible reasons can be very wide.

“…a female pet with a history of being in heat six months ago may have increased thirst and urination because of an infected uterus…Some drugs can (also)cause increased thirst and urination in cats)” - VCA Animal Hospitals

Excessive water consumption could be seasonal

If you believe environmental issues (such as excess heat) may be causing your cat to drink more than usual, you can make changes while continuing to observe your cat’s behavior.

If after addressing any issues in the environment you still notice that your cat is still drinking more water than usual, this could potentially be a sign that your cat has some underlying health issue, and a vet visit may be warranted.

Other than benign causes, the three most common health conditions that cause increased thirst and urination are: Diabetes, Hyperthyroidism, and Chronic Kidney Disease.


Diabetes is a problem with the pancreas and the body's ability to produce insulin in balance with diet and bodily health. Insulin is like a tiny chemical key that opens up individual cells and allows sugar into them, where the sugar is used as energy and food to keep the cell going.

There are two kinds of diabetes.

Type 1 diabetes is typically seen in younger cats and is due to damaged cells in their pancreas.

Type 2 diabetes is generally seen in adult cats and can be caused by a number of factors, but ultimately shows as increased sugar in the blood because the body has developed a resistance to insulin.

Regardless of the kind of diabetes, they both end up resulting in increased thirst and increased urination as their little bodies have to get rid of excess sugar and other byproducts.

Diabetes is common in cats, especially overweight cats, male cats, and older cats. Other symptoms of diabetes include leg weakness, weight loss, increased appetite, and even loss of fur.

Though there is no cure for feline diabetes, the prognosis for a good quality of life is good with adequate management at home. With early, aggressive treatment of diabetes, many cats will enter a state of diabetic remission, meaning they are able to maintain normal blood sugar levels without insulin injections.” - Cornell University College of Veterinary Medicine

Cat Diabetes | Dr. Todd Green, Board-Certified Internal Medicine Specialist | VCA Animal Hospitals - 2:09 Mins


The thyroid produces hormones that affect nearly every organ in the body, so when it’s not functioning properly, you can expect to see changes throughout the body.

Problems with the thyroid can crop up as both hypo- and hyperthyroidism, cases where the thyroid is producing too little or too much of the hormones it controls.

An Older Cat With Hyperthyroidism Image by Toe Beans

Hypothyroidism is very uncommon in cats and won’t cause the symptoms we’re discussing today.

Hyperthyroidism on the other hand is not uncommon. In fact, my angel Moosie cat was diagnosed with hyperthyroidism when he was a teenager. If you want to learn more about this disease check out my in-depth discussion on hyperthyroidism.

Other symptoms besides increased urination are vomiting, diarrhea, weight loss, increased appetite, increased excitability, poor body condition, and an abnormal heart rate.

The problem with cat hyperthyroidism is that it usually comes along with several other serious health conditions including heart disease and high blood pressure.

“Hypertension, or high blood pressure, is another potential complication of hyperthyroidism, and can cause additional damage to several organs, including the eyes, kidneys, heart, and brain. If hypertension is diagnosed along with hyperthyroidism, drugs may be needed to control the blood pressure and reduce the risk of damaging other organs.” - Cornell University College of Veterinary Medicine

Cat Hyperthyroidism | Vets Clinic | 2:44 Mins

Chronic Kidney Disease

I like to think of the kidneys as filters for the body. They are responsible for many functions including water conservation and the removal of waste from the blood stream.

Vet Treating a Cat With Chronic Kidney Disease Image by Toe Beans

“Your cat’s kidney disease may lead to an increase in their thirst and urination. You may notice them drinking a lot more and rushing to the litter box many frequently than they used to...Your vet will want to run tests to determine the cause of your cat’s increased thirst and urination.” - Atlantic Veterinary Internal Medicine & Oncology

When the kidneys begin to lose function over time, it’s called chronic kidney disease or CKD.

This reduced function means the amount of waste they would typically remove from the blood is lessened and more urine is output. Cats will then compensate for the increased output by drinking more water.

While it can show up in cats of any age, CKD is more commonly seen in older cats.

“Chronic kidney disease (CKD) is the most common metabolic disease of domesticated cats, with most affected cats being geriatric (>12 years of age).” - Brown CA, Elliott J, Schmiedt CW, Brown SA.

CKD is ranked in stages as the disease progresses and the level of kidney function diminishes.

Three out of my four now angel kitties all had CKD with the hallmark indicator of increased urination as the disease progressed. You may also notice that your cat has a reduced appetite and is losing weight.

Everything You Need to Know About Chronic Kidney Disease in Cats | Dr. Sarah Wooten, DVM, CVJ | 17:04 min Video

Other Issues

While the above issues are the most common, there are a variety of other causes of increased thirst and urination.

Vets Treating a Cat Image by Toe Beans

Other potential causes include:

  • Other kidney issues. Chronic kidney disease isn't the only kidney issue that can cause thirst and urination. Acute kidney issues and kidney infections can also be responsible.
  • Various hormone disorders. While the thyroid is the usual culprit, there are a ton of other glands and processes that create hormones that, when out of balance, can cause the same symptoms. While uncommon in cats these include diseases such as Cushing's Disease and Addison's Disease.
  • Excessive calcium in the blood. Known as as hypercalcemia, when the body doesn't process calcium or when there's too much calcium in their diet.
  • Liver disease. Much like the kidneys, the liver is responsible for handling bodily fluids, specifically filtering and processing blood. When it's damaged or needs to work overtime, it can cause increased thirst and urination, though you’ll often see other symptoms such as jaundice (yellowing of the skin or white part of the eyes), weakness, and disorientation.
  • Certain kinds of cancer. These can be cancers of the kidneys, liver, thyroid, or other parts of the body related to the urinary tract.
  • Drug side effects. As noted above, if your fur baby is on a medication, particularly for an infection, excess thirst and urination could simply be a side effect.

In some cases, an electrolyte imbalance can also cause the issue. There's also a rare behavioral issue called "primary polydipsia" that involves excess thirst and urination for no reason other than a trained or learned behavior, with no underlying health conditions.

How to Determine What's Wrong

Because increased thirst and urination are oftentimes caused by medical issues, you’ll need to take your fur baby to the vet to get a diagnosis.

A Cat Drinking Water Image by Toe Beans

"The search for answers begins with a complete history and physical examination. A pet's history is the information you give the veterinarian about your pet's illness. History is very important and can provide clues about the cause of increased thirst and urination." – VCA Animal Hospitals.

Your vet will likely ask you questions about your cat’s behavior, what they've been eating, medications they're taking, when you noticed the changes, and if you’ve seen any other unusual behavior. This will help them determine what course of tests they might want to order.

Increased thirst and urination that came on acutely after eating something that isn’t cat friendly may need different tests as compared to a cat that has had the symptoms worsen over time.

Your vet will likely perform a few kinds of tests, beginning with simple physical examination, involving careful prodding and palpating of the abdomen, lymph nodes, and other potentially suspect areas.

One of the best diagnostic tools a vet has is a blood test. Blood can tell you a lot about the health of your cat. A test called a CBC, or Complete Blood Count, will check things like white blood cell and red blood cell counts to look for possible infection.

Your vet may also do a comprehensive metabolic panel, which is another kind of blood test that will analyze things like lipids, proteins, enzymes, sugar, hormones, and electrolytes. All of these need to be within normal ranges, and if they aren't, the specific imbalance can point to a specific disease.

Read More Cat Health Care Guides

Finally, a urinalysis will check for kidney function and look for infections of the urinary tract, which will help add more details to the overall picture.

If hyperthyroidism is suspected, your vet may also want to run a specific blood test to check your cat’s thyroid function to confirm the diagnosis.

How to Treat a Cat with Increased Thirst and Urination

The treatment plan will obviously depend on the cause of the increased thirst and urination. The good news is the common causes we noted above are easy to diagnose with simple blood tests and there are treatment options.

A Vet Treating a Cat Image by Toe Beans


If your cat’s glucose comes back high, your vet will likely prescribe insulin for you to inject at home. This might come as a scary diagnosis, but I can tell you from personal experience, with a little training and practice, you’ll be a pro in no time.

My angel Moosie was initially diagnosed with diabetes due to his obesity. If your kitty is in a similar situation, a change in diet, exercise, and weight loss can put your kitty into remission.

He was diagnosed with diabetes again several years later, this time unrelated to his weight. When you have a diabetic cat, it’s going to be important to test their glucose level and ensure they are receiving the correct dose of insulin.

You’ll likely have frequent discussions with your vet at the beginning of treatment until you reach the correct dosage to keep your fur baby in a healthy range.


An overactive thyroid will clearly show up on a blood test and the good news is it’s almost always caused by a benign tumor. A daily medication to help regulate hormone production is the most common treatment option, though it treats a symptom and not the root cause, the tumor.

Other treatment options are available, so talk with your vet to see if an alternative option is best for you and your kitty.

Chronic Kidney Disease

If you take your kitty to the vet annually for check-ups and do periodic bloodwork, you’re likely to receive a CKD diagnosis before you ever notice any symptoms.

The good news is early diagnosis means you can make changes to slow the progression of the disease. Your vet may recommend diet changes such as prescription wet food that is easier on the kidneys. They may also recommend you begin a potassium supplement, which can be sprinkled on your kitty’s food.

In more progressed cases of CKD, your kitty may need to be treated with subcutaneous fluids to address dehydration. CKD can also cause increased blood pressure so you may end up with a daily prescription that will need to be given.

Kidney disease will progress at a different rate depending on the cat, but I can tell you from experience small changes early, regular monitoring, and tweaks along the way, will allow your kitty to live for many years with the diagnosis.

Have you noticed increased thirst or urination in your kitty? What was the diagnosis? How have you dealt with treatment? Share your story below so other pet parents can learn from your experience.

K Marie Alto
K Marie Alto

K. Marie is an animal lover, wife, kitty mom, dog auntie, writer, and co-founder of Toe Beans, a proud American family-owned online boutique pet supplies store focused on the improvement of the life of furry family members via pet parent education, better products, and advocacy. She has over 20 years of experience as a pet momma. She loves sharing her personal journey and experience as a pet parent via her blog and Facebook page where she currently has more than 50K followers (@furrytoebeans) and counting :-). Read more

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