Why Is My Cat Drinking a Lot of Water?

Sandra C. Mitchell, DVM, DABVP
By Sandra C. Mitchell, DVM, DABVP on Feb. 28, 2023
calico cat dipping paw in water from sink faucet

It used to be that you could fill your cat’s water bowl once a day. But now you’re filling it two or three times a day, and your cat comes running to have a drink every time you turn on a faucet. 

What is going on? Is drinking more water normal for older cats? Or is there a medical condition you need to worry about?

Here’s why your cat might be drinking more water than normal and when you should consult with your vet.

Key Takeaways

  • Various underlying health conditions can cause a cat to drink an excessive amount of water.
  • Keeping track of how often your cat visits the water bowl can help you get an idea if they are drinking more than normal.
  • Never withhold water from your cat, unless directed by your veterinarian.

Health Tools

Not sure whether to see a vet?

Answer a few questions about your pet's symptom, and our vet-created Symptom Checker will give you the most likely causes and next steps.

How Much Water Should Cats Drink Daily?

Before you know if your cat is drinking an above-average amount of water, you need to know what the normal range is for a cat’s daily water intake. Cats will generally drink about 4 ounces of water per 5 pounds of body weight. So a 10-pound cat will typically drink about 8 ounces of water every day.

Larger cats and very active cats will drink more than smaller or inactive cats. Some cats just naturally don’t drink very much, while others will drink more often. The thing to watch for is any change in your cat’s water consumption. Is it going up or down over a period of a few weeks or months? A change in their patterns could be cause for concern.

Factors That Affect How Much a Cat Drinks

The biggest factor that affects thirst is a change in diet, particularly if you switch your cat from dry food to wet food or vice versa. Cats eating dry food drink more to make up for the lack of water in their food. Canned food, however, has plenty of moisture, so cats tend to drink less.

Cats may also drink more water when it’s hot outside. This should go immediately back to normal once it cools off again. If it’s hot or dry, try setting up a humidifier to help keep your cat cool and decrease the need for more water.

How to Track How Much Water Your Cat Is Drinking

Determining how much water your cat is actually drinking can be tricky, particularly if more than one water source is available or there are multiple pets in the household.

The simplest way to track water intake is by using a single water bowl and a measuring cup. Clean the bowl in the morning and put in a measured amount of water. The next morning, measure how much water is left and subtract from the original to calculate how much water your cat drank.

You can also get a water bowl with measurements marked on the side, or a smart water fountain to measure how much water your pet drinks:

Water bowl behavior can be important to note as well. Most cats will visit a water source frequently to drink, often five or six times per day. Keeping track of how often your cat visits the water bowl can help you get an idea if they are drinking more than normal. You can set up a pet camera to help you keep track.

Also keep in mind that what goes in must come out, so you may see larger-than-normal urine clumps in the litter pan because your cat is peeing more. In fact, the first sign of a problem might be if the litter box is getting full more quickly and the clumps are getting heavier and harder to scoop. If you notice this, talk to your vet and start actively monitoring your cat’s water intake.

Why Is My Cat Drinking So Much Water?

There are several common reasons why your cat might be thirstier than usual:

Kidney Problems

The most common reason older cats begin drinking and urinating excessively is because their kidneys are starting to decline. The kidneys are responsible for filtering the blood and producing urine. As cats age, their kidney function decreases. As a result, some of the water in the bloodstream isn’t filtered properly, so more fluid is turned into urine. This then causes dehydration.

This is normal to some degree, but it may also signal underlying kidney disease, also known as chronic renal disease (CRD) or chronic kidney disease (CKD). This is a progressive disease, and it is better to catch it early on.

If you notice your older cat drinking and urinating more, especially if they are losing weight, not eating as well, or showing changes in their personality, it’s time to schedule an appointment for an exam and possibly a kidney screening.

Hyperthyroidism and Liver Disease

Other diseases or conditions that may cause increased drinking include hyperthyroidism and liver disease. These are more common in middle-aged or senior cats. Cats with hyperthyroidism usually seem hungry all the time and lose weight, while cats with liver disease usually have less of an appetite.


Diabetes is also a very common cause of drinking and peeing more in adult and senior cats. With diabetes, the pancreas is not secreting enough insulin to control the blood sugar. As blood sugar levels rise, the cat will become thirstier and will need to urinate more often.

This is most commonly seen in overweight, young to middle-aged cats that primarily eat dry food. You want to get a cat with diabetes diagnosed as early as possible so it can be treated aggressively. Delaying therapy can lead to severe and potentially life-threatening consequences.

Urinary Tract Infections

Urinary tract infections (UTIs) may also cause a cat to drink more water. UTIs are most common in younger to middle-aged cats. Affected cats often urinate small amounts frequently as opposed to the large, heavy urine clumps seen with the other conditions.

Cats with UTIs may be restless and uncomfortable. If you see these signs, take your cat to a vet right away, especially if he’s a male, as this may be a medical emergency.  

Medication Side Effect

Some medications, such as steroids and diuretics, may also cause a cat to drink more. If your cat is prescribed a new medication, ask your veterinarian if increased thirst is a known side effect. Changes in water intake caused by a medication should go away as soon as your pet is off the medication as ude kidney disease, diabetes, or Cushing’s disease.instructed by your veterinarian.

Why Is My Cat Peeing So Much?

Cats that drink a lot of water will go on to urinate more often. This is partially due to how the body processes water. If a cat is drinking a large amount of water, then a higher volume will then be processed through the kidneys, leading to a larger output of urine. 

When to Go to the Vet for Excessive Thirst in Cats

If you notice that your cat is drinking more than normal and it’s not associated with temporary factors like the weather, fluctuations in humidity, or a change in diet, it is time to contact your veterinarian and schedule an appointment. 

If your cat is showing any additional symptoms, such as weight loss, lethargy, or changes in appetite, try to get to the vet as soon as possible. It is often helpful to your veterinarian if you can bring a urine sample along to the appointment, which may save a step in the diagnosis.

If your cat is male and seems to be having any trouble urinating, or he is urinating only small amounts frequently, he should be examined immediately, as this may be an emergency.

How Vets Diagnose the Cause of Excessive Thirst in Cats

During an exam, your vet will ask a lot of questions about your cat’s behavior, changes in their health status or patterns, and anything else that might be affecting their water consumption. They may ask about the type and amount of food you’re feeding and your cat’s litter box habits.

Your veterinarian will likely recommend blood and urine tests. In most cases, these tests are enough to get to a diagnosis. If a blood and urine test aren’t enough, your vet may also want to do ultrasounds or X-rays.

It may be possible to start a treatment plan early. Many of the causes of excessive thirst are ongoing problems, like diabetes and kidney disease, so more testing will be needed to monitor the treatment over time.

Treatment for Conditions That Cause Cats to Drink a Lot of Water

For cats experiencing age-related changes in kidney function, treatment is aimed at controlling symptoms, maintaining your cat’s appetite, and keeping their blood values within an appropriate range. Your veterinarian will probably rate the severity of your cat’s kidney disease using International Renal Interest Society (IRIS) guidelines, and they will recommend a treatment plan based on stage of the disease.

Cats with diabetes often need to change to a canned, high-protein diet. They will also need to have an insulin plan, along with regular blood sugar monitoring. If diabetes is caught early and treated aggressively, some cats can go into remission, which is when they maintain a normal blood glucose level for four weeks without intervention.

Kitties with hyperthyroidism are often treated with methimazole to control thyroid function. This can be given as an oral medication or a topical gel that can be rubbed into their ears. They may also be treated with radioiodine therapy, which can be extremely effective. Cats tolerate radiation very well, and a cat will only need to stay several days in the hospital after treatment. Most cats that undergo this treatment are cured.

Cats with liver disease often need more diagnostic tests before a treatment plan can be made.

Cats with urinary tract infections or crystals can often be treated with antibiotics or diet changes.

Featured image: iStock.com/akirkman

Sandra C. Mitchell, DVM, DABVP


Sandra C. Mitchell, DVM, DABVP


Sandra Mitchell is a 1995 graduate of the New York State College of Veterinary Medicine. Since graduation, she has worked in many fields...

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health