Pet Health
why is my cat drinking a lot of water

Cat Drinking a Lot of Water - Why Is My Cat So Thirsty?

Written by Ryan Gliozzo


If you're concerned about your cat's excess thirst, here are some reasons why and what you can do to address the issue.
Cat looks into whirlpool


Your cat has been drinking a lot of water lately. What should you do?

Some cats drink a lot of water due to an underlying disease, boredom, or anxiety. Lack of exercise can also make your cat drink more water. If you're concerned about your cat's excess thirst, here are some reasons why and what you can do to address the issue.

What is a normal amount of water for a cat to drink?

Cat and dog figurines handing off glass of coffee

Water is essential for cats, just like it is for humans. Most cats need about one cup of water per day. While some cats may drink more or less, a normal amount for a cat to drink is typically about one to one and a half cups.

The generally accepted formula for calculating this is around 10ml-30ml per pound of body weight per day.

However, if your cat seems to be drinking a lot of water and does not seem to have any other symptoms, then a trip to the vet may help. All Waggel members get free access to Joii, an online vet care system available 24/7.

How do I measure the amount of water my cat drinks per day?

a cat drinking from a bowl of water

As mentioned, a cat needs at least 1 ounce of water per pound of body weight per day. So, a 10-pound cat should drink at least 10 ounces of water per day or around 1 cup.

You can measure how much water your cat is drinking by using a specialised and super-fancy food and water dish that records how much water is consumed each day. 

The dishes come with a small tube that attaches to the side of the dish and runs down into the water. As the cat drinks, the water level rises and is recorded on a chart or in a digital read-out.

This will tell you how much your cat is drinking each day. If your cat does not drink all the water in the dish, you can refill it as needed.

Alternatively, if you want to go old school, you can simply measure out the water in a separate measuring jug, and if the cat drinks it all, refill their bowl and add up the total measurements.

What are some of the reasons why cats drink more than usual?

We're so glad you asked, that's what we're here for today...

Does your cat drink more water because of diabetes?

Diabetes (otherwise called Diabetes Mellitus) in cats can be something which affects mainly middle and older age pets and is something which could cause your pet to drink lots of water in larger volumes.

A normally healthy feline has the correct amount of blood glucose levels, and the pancreas produces just the right amount of insulin to help regulate the cat's energy needs. When there is either too little or not enough insulin, diabetes occurs.

This can cause your cat to drink more than usual. But why is that?

Cats with diabetes get very thirsty because they have too much sugar in their urine, which causes them to lose water more promptly.

Some breeds, such as the Burmese, tend to be more prone to diabetes than others. However, for all cats, at any age, the risk decreases with good levels of activity and a complete, balanced, diet.

Because cats can't quite read the latest diet fads, it's up to you, their owner, to measure their water intake and if you have any concerns, please call your vet as soon as possible to determine if diabetes is the possible cause.

A quick blood sugar test could easily determine if this is the cause and checking any older cats' blood sugar levels should be done as part of a full checkup if you think your cat has any issues.

a cat sat over a bowl of water

Kidney Disease

Around 1%-3% of all cats suffer from Chronic Kidney Disease (CKD), a condition in which the kidneys fail. Chronic kidney failure means they lose their ability to filter waste products out of the blood and keep them at an appropriate level.

Instead, waste products accumulate in the bloodstream and cause problems throughout the body. Cats with CKD may experience weight loss, vomiting, diarrhoea, lethargy, excessive thirst, increased urination, and decreased appetite.

That doesn't sound good at all, but you can contact your vet who will help to diagnose the problem and provide treatment options.

If your cat is showing signs of kidney disease, you need to take him/her to the vet immediately.

In addition to this, you should also make sure that your cat gets plenty of exercise and fresh air every day. This helps to flush toxins out of the body and keeps their organs working properly.


Hyperthyroidism affects about 1 in every 200 cats. The main symptoms are increased appetite, excessive drinking, weight loss, and lethargy. Cats may also become aggressive, anxious, or depressed. Hyperthyroidism usually occurs when the thyroid gland produces too much thyroxine, a type of thyroid hormone. Thyroxine helps regulate metabolism, so an increase in its production can lead to higher metabolic rates and a need for more water.

That's super technical, but a succinct explanation of the issue. If you suspect your cat has hyperthyroidism or an overactive thyroid, then they will have enlarged thyroid glands. These glands secrete excess amounts of hormones called thyroxine, causing the thyroid gland to swell. In turn, this leads to changes in metabolism and other bodily functions.

As well as an increase in thirst being a symptom, your cat will likely show other clinical signs like being overweight, having trouble sleeping, and being restless. They may also become aggressive or depressed.

You can treat hyperthyroidism by administering anti-thyroid medication to reduce the hormone production. The most common method used is radioactive iodine therapy.

However, if you notice these symptoms in your cat, then you should seek medical attention immediately.


In conclusion, if your cat is drinking more water than normal, it could be due to one of the three reasons listed above. If you find this to be the case, it is important to take your cat to the vet for a check-up to discover any medical issues. This will help you determine the cause of the excessive drinking and get your cat on the road to recovery.

It is always recommended, however, that you keep your cat supplied with plenty of fresh water at all times.

That's why it's so important to have a good pet insurance plan which will help to cover your pet for any of these unforeseen issues.

Waggel's Lifetime pet insurance can cover your cat from a kitten, to a senior and for a wide range of health issues including dental and cancer treatment.

Oh, and we also offer some fantastic money-saving rewards just for being a member. Sounds good? simply spend a few seconds and get a quote today to see how much it would cost to cover your pet.

Waggel Pet Insurance

Need more help? You're in luck if you're a Waggel Pet Insurance member. Along with our excellent coverage, we offer access to a 24/7 online vet to answer all your sticky questions, especially if you need grooming assistance.

Not a member? Why not get a quote now and cover your furry friend for a range of illnesses, all while enjoying our amazing perks and rewards.

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