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Excessive Thirst in Cats (Polydipsia): What Does It Mean?

Do you have a thirsty kitty? Is s/he always lapping up water for minutes but still seems thirsty afterwards? Excessive thirst in cats could be a sign of a serious underlying health issue. 

As cat parents it can be hard to tell between a curious kitty who just likes to drink from a running tap (ah hem.. Yoda..) or is actually trying to solve a rather unquenchable thirst due to a related health or behavioral problem.

In this article, we discuss excessive thirst in cats and how to identify the probable causes of excessive thirst in cats.

Excessive thirst in cats | Fluffy Kitty

How can I tell if my cat is excessively thirsty?

Being able to tell whether or not your cat is excessively thirsty requires your good observation skills. If you can answer “yes” to the question, “Is my cat drinking lots more than usual?” then most likely your cat’s extra thirst is for a reason.

In addition to your cat’s excessive thirst, you may notice that s/he urinates much more frequently. Why’s this? Your cat is trying to drink more water in order to compensate for all the water lost during frequent trips to the potty.

If you do notice your cat showing signs of excessive thirst or excessive urination (polydipsia and polyuria) then it’s very important to make a trip to the veterinarian for a full physical examination!

Is excessive thirst in cats a health or behavioral issue?

Of course it’s normal during the summer months for your cat to drink a little extra, but if you really notice a drastic increase in thirst, it could be early warning signs of a serious health issue.

If the excessive thirst stems from a health-related issue, your cat may also experience excessive urination, rapid weight loss, vomiting, dehydration, lethargy, among other symptoms of illness.

Excessive thirst in cats could also be due to behavioral-related problems linked to anxiety or stress, but in either case, excessive thirst in cats is not a good sign. Consult your vet as soon as possible if your cat is showing signs of excessive thirst and urination.

Excessive thirst in cats | Fluffy Kitty

Possible causes of excessive thirst in cats

There is a range of serious diseases that could cause excessive thirst in cats.

Reminder: If your cat displays excessive thirst, it’s important not to wait to go to the vet. In order to get a proper diagnosis of any of the below potential causes, consult your veterinarian right away. Your vet will discuss the best solutions and treatment options for you and your cat.

Diabetes mellitus

Feline diabetes is a common disease in cats. Cat’s with diabetes will have excess blood sugar levels (hyperglycemia) due to the inability to produce or use insulin. Diabetes in cats will display one or more of the following symptoms:

  • Excessive thirst
  • Increased urination
  • Lethargy
  • Sudden weight loss
  • Loss of appetite
  • Vomiting
  • Dehydration

Your cat’s excessive thirst may be caused by diabetes, but having excessive thirst does not automatically mean your cat has diabetes. A proper diagnosis by a veterinarian is necessary to determine whether or not your cat indeed has feline diabetes.

Kidney disease

Another common cause of excessive thirst in cats, chronic kidney disease in cats is the failure to filter or reabsorb fluids. Watch the video below by Dr. Karen Becker for a greatly detailed explanation of chronic kidney disease in cats.


Hyperthyroidism is yet another probable cause of excessive thirst in cats. This occurs when your kitty’s thyroid gland produces too many hormones due to excess cell growth. It is rare for younger cats to get hyperthyroidism, but is common with senior cats; the average age being between 12 and 13 years old.

In addition to excessive thirst, cats with hyperthyroidism will display signs of:

  • Drastic weight loss
  • Increase in appetite
  • Hyperactivity
  • Increase in urination
  • Vomiting and diarrhea

Urinary Tract Infections (UTIs)

Excessive thirst in cats could also be caused by a bladder infection. However, though appearing less dangerous at first, if left untreated, feline UTIs can become serious.

Cat’s with UTIs will often display signs of excessive thirst in addition to frequent urination (usually outside the litter box).

If you notice your cat:

  • strains or is in pain during urination,
  • has blood in the urine,
  • has excessive thirst and/or,
  • shows unusual urination patterns

then it’s likely due to a feline UTI. Bladder infections can worsen if left untreated, so be sure to get treatment for your kitty as quick as possible.

…among others

It is important to note that the list above is not exhaustive. There are indeed other reasons that would cause excessive thirst in cats, but the ones above are the most common. In any case, make sure to monitor your kitty’s water intake. Also be sure to report any unusual increase to your vet.

Excessive thirst in cats | Fluffy Kitty

What’s normal for your cat to drink per day

The normal requirement for water intake for a cat is on average, 60 ml per kg per day.

60 ml = 2 fluid oz

1 kg = 2.2 lbs

For example: Our fluffy Yoda weighs around 4.5 kg (= 10 pounds). This means Yoda should intake around 270 ml (or 9 fl oz) of water per day.

Between 5 to 10 fluid ounces is normal.

–> 5 fl. oz equals over 1/2 cup (0.625).

–> 10 fl. oz equals 1.25 cups of water.

Calculate your kitty’s daily water intake requirement by multiplying 60 ml by your cat’s weight (in kg).

Final thoughts: Excessive thirst in cats

We hope you were able to take away some useful information from this article. Please never hesitate to consult your vet, who will provide you with the best information to treat and protect your kitty.

As we saw in this article, excessive thirst in cats could be a symptom for a number of different illnesses. We always want to ensure the best for our fluffy friends so please always consult your vet when it comes to your kitty’s health. Of course, Fluffy Kitty is here to answer any additional questions or comments you may have!

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