Your Cat Is Thirsty – Find Out Why

Author: Dr. Jason Nicholas

Published: September 1, 2015

Updated: April 6, 2022

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thirsty cat

Why Your Cat May Be So Thirsty

An increase in thirst is quite a common thing for cat owners to mention during vet visits.

Of course, it’s also common for them to miss the increased thirst, but bring up the other “end” of the issue… increased urinations.

Were you aware though that there are actually many potential causes of increased thirst and urinations in cats?

Factors that Increase a Cat's Thirst

  • A change in the weather and/or humidity
  • A change in your cat’s activity level
  • A change in your cat’s food
  • A urinary tract infection
  • An overactive thyroid gland
  • Progressive kidney disease
  • Diabetes

As you can see, even just from this partial list, there are many possibilities. And what’s more, each of them warrants their own level of concern.

A visit to your vet will be necessary to determine the actual underlying cause in your cat’s particular case.

Three things you can do prior to visiting your vet to help the work-up along

  1. Pick up some Keto-Diastix at your local pharmacy. These are easy-to-use keto diastix test stripreagent strips that allow you to quickly and reliably check for the presence of glucose (sugar) and/or ketones in your cat’s urine.

    The presence of glucose in your cat’s urine may indicate diabetes, while the presence of ketones may indicate the presence of a severe metabolic emergency of undiagnosed or uncontrolled diabetes or diabetic ketoacidosis (DKA).

    Learn more about diabetes and DKA in cats. Note: glucose or ketones in your cat’s urine is NOT definitive for diabetes or DKA, as either can be present for a few other reasons, too.

  2. Measure the amount of water your cat is actually drinking in a 24-hour period.
    • Fill their water bowl(s) with a measured amount of water first thing in the morning, then keep a running total of additional water you add throughout the day (if any).

    • First thing the following morning, subtract the amount of water still left in the bowl(s) from the total to determine how much water your cat drank in the preceding 24-hour period.

    • Do this a couple of different days and bring those numbers to your vet so they can calculate if your cat’s water consumption is truly excessive. (*Note that this can be more difficult to do in a home with multiple pets, but it can still be accomplished by separating out the cat in question for a day or two to specifically measure their daily water intake.)

  3. Read about the information your vet can get from testing your cat’s urine and what it can mean. You'll also get tips on how to collect your cat's urine.

How Much Water Should a Cat Drink – How Much is Too Much?

cat stethoscope

If your cat is persistently drinking more than 0.8 ounces per lb (50mls per kg) of body weight per day (24-hour period), it could be excessive and mean that a veterinary evaluation is necessary. Anything persistently over 1.5 ounces/lb/day (100mls/kg/day) is definitely excessive and in need of veterinary evaluation. 

For example, a cat that weighs 9 lbs would be drinking too much if they drank over 7 ounces per day, and if they drank over 13.5 ounces, that would be way too much.

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About the author

Profile picture for Dr. Jason Nicholas

Dr. Jason Nicholas

Dr. Nicholas graduated with honors from The Royal Veterinary College in London, England and completed his Internship at the Animal Medical Center in New York City. He currently lives in the Pacific Northwest.

Dr. Nicholas spent many years as an emergency and general practice veterinarian obsessed with keeping pets safe and healthy. He is the author of Preventive Vet’s 101 Essential Tips book series.

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