Why is my cat drinking a lot of water

Why is my cat drinking a lot of water?

It isn’t normal for cats to drink lots of water frequently. Compared to dogs, they just drink half as much per kilogram of their body weight every day.

A ravenous thirst or excessive drinking of water shows that your feline friend may have a health condition. And this should incline you to get them to their veterinarian quickly for a check-up.

So we will now explore the reasons why your cat is drinking a lot of water, how much should they drink, and what you can do about it.

Reasons Your Cat Is Drinking a Lot of Water

Reasons Your Cat Is Drinking a Lot of Water

Polydipsia is a term for the condition of cats drinking too much water. There are several causes for this, but the three main ones are:


A PubMed study finds that 20.72% of cats ages 10 years or older are affected by hyperthyroidism.

Hyperthyroidism is a condition whereby the thyroid gland produces excess thyroid hormone. This hormone is responsible for the growth, metabolism, and brain function of the cat.

Now, if the metabolism of the cat is faster, the cat tends to be hungrier and thirstier.

Plus, the thyroid hormone can block the antidiuretic hormone (ADH), preventing it from interacting with the kidneys. What happens then is less water will be retained in the body, with the rest being flushed out as urine.

Chronic Kidney Disease

According to Iris, 1% to 3% of cats have chronic kidney disease, with it being more common among the older population.

The function of the kidneys is to maintain the balance of water in the cat. If they’re not working right, the water will be sent out along with the urine, contributing to a cat’s thirstiness.


Cornell University estimates that about 0.2% to 1 % of cats will be diagnosed with diabetes mellitus during their lifetime.

Diabetes mellitus happens if the cat does not have enough insulin in the body. Insulin is an essential hormone, as it allows glucose or blood sugar to be used by the liver and muscles as energy.

Without ample insulin, glucose can’t be absorbed by the body. And so, your kidneys have to get them out of your body through your urine by osmosis or diluting the urine with water.

As a result, the cat becomes increasingly thirsty as their bodies need more water to function normally.

Aside from that, other less common causes of polydipsia are the following:

  • Medications
  • Liver disease
  • Hypercalcemia
  • Pyometra
  • Cancer

How much water should a cat drink?

In general, a healthy cat drinks between 39.6ml to 59.4ml of water per kilogram of their body weight. So if your cat weighs 4.5kg, they need to consume approximately 178.2ml to 267.3ml per their weight daily.

However, other factors can alter this range including the cat’s age, diet, environment, eating canned cat food (since it has water content already), health, and medications.

What can you do if you notice your cat is drinking too much?

If you notice your cat is drinking more than 45ml every day—even though this is in the healthy range we specified—it’s best to consult with a veterinarian to see if that’s normal.

In addition, if you see other signs of polydipsia, such as increased thirst, lower body weight, and reduced activity, among other sickly conditions, have them checked up by a cat doctor as soon as possible.

And it helps if you have taken out pet insurance. This will keep the cat’s check-ups and treatment much less stressful and expensive.

More Products & Services That Can Help with Cat Care

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