Cat Drinking a Lot of Water Suddenly? Why & How to Help!

Water is one of the most important nutrients a cat needs to be healthy and survive, so it’s often a good thing when you see your feline head to its water bowl. Sometimes though, a cat’s water intake suddenly increases to the point of seeming excessive. In these cases, this behavior can seem concerning, and it can be hard to know if it is classed as “normal” or not.

When my cat’s drinking habits changed, I found myself thinking things like, “Why is my cat drinking a lot of water suddenly?”, “Is my cat drinking too much water?” and “How do I know if the change is normal or the sign of something more serious?”.

I decided to research this topic to know best how to look after my kitty, and I thought I’d share this newfound wisdom with you! Read on to find out what is considered a normal amount of water for your cat to consume, some diseases that can cause such behavior, and what steps you should take to ensure your feline is happy and healthy.

What Is Normal Water Intake for Cats?

When it comes to water intake, every cat is different. Your feline’s environment, lifestyle, and health will all influence the amount of liquid they need to consume each day.

In 24 hours, a healthy cat should consume anywhere between 20ml and 90ml of water for every kilogram of body weight. Depending on your feline’s age and weight, this could be between 70ml and 300ml daily. Keep in mind that this includes water that your cat drinks and that which they gain through their food.

Generally, drinking at least 100ml of water per kilogram of body weight per day is considered excessive for a cat. However, a smaller amount of liquid could still be classed as abnormal if your kitty doesn’t usually drink much. You know your cat best, so if you think their drinking has become excessive, it probably has.

Noticing that your cat is spending more time at their water bowl is usually an indicator that something is different, but if you want to measure how much water they are drinking, there is a simple way of doing so. All you need to do is fill their water bowl with a known amount of water and measure how much is left at the end of the day. The difference will be how much your feline has consumed.

If you use this technique and have multiple pets, you will have to isolate your cat so that you know any of the missing water has been drunk by the correct animal. Outdoor cats must also be kept inside, as they often drink from water sources outside your home.

Why Is My Cat Drinking So Much Water?

It can be disconcerting if your feline suddenly decides to consume tons of water, especially if they’ve never been one to drink much day-to-day up until then. This behavior can usually be spotted by watching to see if your cat makes increased trips to their water bowl, needs their water bowl refilling more frequently, or suddenly starts drinking from unusual places (e.g., the faucet).

In some cases, this change would be considered normal. For example, after I brought some stainless steel cat water fountains a few years ago, my feline’s started drinking much more than they used to. Other examples include if the weather was scorching or if you’ve switched your cat’s diet to dry food.

However, if there are no apparent reasons behind your kitty’s excessive drinking, the sudden behavior change could be a sign of disease. The excessive thirst caused by such conditions is called polydipsia. Below, I’ve outlined seven possible reasons for your cat’s polydipsia and tell you exactly how you can spot them.

1. Chronic Kidney Failure

Chronic kidney failure (also known as chronic kidney disease) is one of the most common health conditions seen in older cats. The disease tends to get worse over time, with symptoms becoming more disruptive to your kitty’s quality of life as time goes on.

For many cats, the cause of their chronic kidney disease is unknown, but some conditions have been identified as potential triggers. These include kidney tumors, polycystic kidney disease (which causes the kidney tissue to be replaced by cysts), kidney infections, and the consumption of toxins. Research is still being carried out to discover other causes. 

Among many other functions, the kidneys regulate fluid levels in the body. Because the ability to absorb water is disrupted, your kitty will likely urinate more. They then compensate for this by drinking more water. If you’re wondering how often you should see your cat urinate in 24 hours, the answer is up to four times. Anything more than this could be seen as abnormal.

Chronic kidney failure is a progressive disease, so any symptoms your cat displays will usually be quite mild initially. However, there have been cases in the past where the progression of symptoms has become rapid. This sudden deterioration is usually due to a swift worsening of the disorder.

Some other symptoms of chronic kidney failure to look out for include:

• Increased thirst
• Lack of appetite
• Sudden weight loss
• Poorly kept coat
• Fatigue and/or weakness
• Increased urination
• Vomiting
• Foul-smelling breath

Although chronic kidney failure is likely incurable, there are various treatments available that can significantly improve your kitty’s quality of life. They can also help slow down the progression of the disease, meaning you’ll enjoy the company of your furry friend for a longer time.

2. Diabetes Mellitus

Diabetes mellitus is a condition that results from the inability to regulate blood glucose (i.e., sugar levels) and is one of the most common endocrine disorders in cats. It is caused by a lack of insulin, a hormone released in response to increased sugar levels.

In cats, diabetes tends to be like type-II diabetes seen in humans; it is caused by abnormalities within the pancreas preventing the production of sufficient levels of insulin. This is also paired with the reduced ability of your kitty’s body cells to respond to the little insulin produced.

The role of insulin is to help the sugar in the bloodstream be absorbed by body cells so that it can be used for energy. When there is an insufficient level of insulin, sugar leaks into your feline’s urine, drawing water along with it. This, in turn, creates a larger volume of urine and means your kitty drinks more to compensate for the lost water.

The severity of symptoms will vary between cats, but some of the other signs you may notice are:

• Unexpected weight loss
• Poorly kept coat
• Increased appetite
• Weakness

Upon examination, your vet may also notice that your feline’s liver has enlarged. Any signs of diarrhea, vomiting, anorexia, or collapse should also prompt a visit to your vet, as they could be signs that a complication known as diabetic ketoacidosis has developed.

Treating diabetes mellitus will be different for each cat and will require a lot of dedication from you as your feline’s owner. Cats that are overweight are at a higher risk of developing the disorder, so their diet is likely one of the first things that will need to change. You may also need to provide your kitty with insulin injections.

3. Hyperthyroidism

Hyperthyroidism is another condition that is very common among older felines. The disorder is progressive and results from overactive thyroid glands releasing high levels of thyroid hormones. These hormones control a cat’s metabolic rate, so those suffering from hyperthyroidism tend to burn energy quickly. So, if you often think, “My cat is always begging for food,” this could be the cause.

In most cases, the disease develops when one or both of a feline’s thyroid glands enlarge, resembling non-cancerous tumors. In over 70% of cases, both thyroid glands are affected, but the cause of this change is unknown. Occasionally, hyperthyroidism can be caused by a cancerous tumor. However, this is extremely rare, with it only being the underlying cause in under 2% of cases.

If your furry friend is suffering from hyperthyroidism, they will show a wide variety of symptoms, but these will become more apparent as the condition progresses. The most obvious signs to look out for are listed below:

• Poorly kept coat
• Increased activity and/or irritability
• Sudden weight loss
• Increased appetite
• High heart rate (tachycardia)
• Vomiting and/or diarrhea
• Sensitivity to heat, including open mouth breathing

Thankfully, hyperthyroidism is one of the diseases listed here that can be reversed! If the disorder is caught in time and treatment is successful, most cats will be able to recover fully.

4. Liver Failure

Liver failure is an extreme form of liver disease that occurs when large portions of the organ are severely damaged. The liver is located in the abdomen and is responsible for maintaining your cat’s metabolism and regulating its immune system.

The most likely cause of liver failure in cats is the ingestion of toxins. The liver’s blood supply comes from the gut, so any toxins your kitty eats will quickly reach and damage their liver. Felines also lack certain metabolic pathways in the liver that usually prevent such damage, making them even more susceptible.

Aside from this, there are also a variety of other conditions that can damage the liver. I’ve already spoken about some of these, such as hyperthyroidism and diabetes mellitus.

Fortunately, over two-thirds of the liver need to be severely affected for liver failure to occur, so the progression from liver disease to this more dangerous condition is rare. In addition, the liver can regenerate, so it can repair itself even after severe liver disease.

Some of the main signs of liver failure are as follows.

• Lack of appetite
• Sudden weight loss
• Fatigue
• Fever
• Jaundice (yellowing of gums and skin)
• Increased thirst
• Vomiting

In more severe cases, liver failure can lead to increased salivation, disorientation, blindness, and seizures. At times, it can also cause fluid buildup in the stomach. This is likely the culprit if you notice your cat’s stomach is bloated and hard.

6. Urinary Tract Disease

Urinary tract disease is an umbrella term that describes various conditions affecting your cat’s urethra and bladder. It is often the culprit when you find your cat peeing everywhere all of a sudden while they have been perfectly litter trained in the past. Felines that are middle-aged and are either overweight or neutered are most at risk.

There are various underlying causes of urinary tract disease, but some are more common than others. Some most likely include bladder stones, bacterial infections, tumors, and anatomical defects. This being said, the disease is classed as idiopathic (having no cause) in around 65% of cats.

The symptoms of different urinary disorders are all very similar, so it is hard to determine the underlying condition without thorough tests. You can, however, still identify whether or not your kitty has a urinary tract disease in general. Some of the signs to look out for include:

• Increased and/or painful urination
• Over-grooming around the genital area
• Blood in the urine
• Increased aggression and/or irritation
• Sudden urination outside of the litter box

Occasionally, urinary conditions also cause an inability to urinate. If you notice your cat is eating and drinking but not peeing, contact your vet straight away. The issue is likely caused by a blocked urethra and should be treated as an emergency.

Treating a urinary tract disease will vary depending on the underlying cause but encouraging increased water intake is always a good idea. Just make sure to never force a cat to drink water. You can also look into a litter for cats who pee outside the box if this is one of the symptoms you end up facing.

7. Fluid Compensation

Finally, we have fluid compensation. While not an illness itself, this can still lead to your cat drinking excessive amounts of water.

Many other conditions that your feline friend could be suffering from lead to feelings of increased thirst. Prime examples of this would be vomiting or diarrhea, as both of these symptoms result in a lot of water loss. To compensate, your kitty will drink much more regularly than usual so that they can replenish their water levels.

I’ve already described some examples of fluid compensation when talking about other conditions (i.e., chronic kidney failure and diabetes mellitus). The primary form of treatment focuses on curing the underlying disease so that the related symptoms can be relieved.

What Should I Do If My Cat Is Drinking Excessive Water?

If you’ve noticed your cat is drinking excessive water, keep an eye out for any other signs that they may be unwell. This could be as subtle as seeing that your cat keeps trying to pee, but only a little comes out, or as clear as noting that your cat coughs after drinking water. Increased hiding behaviors are also a clear indicator that something is wrong.

Signs of illness should be taken seriously, so contact your vet if your feline appears ill. By informing them of your cat’s increased drinking habit and any other symptoms, your vet should be able to make an appropriate diagnosis of what is wrong and start treatment.

Sometimes, your furry friend will start drinking more water without showing any other signs of illness. In this situation, your kitty’s behavior is most likely due to a change in its environment. For example, consider whether it has been warmer than usual lately or if you’ve recently changed your cat’s diet. Changes such as these that seem fairly small to us can make a big difference in your kitty’s habits.

As long your cat doesn’t seem ill, there is no reason to book an appointment with your vet. It should be enough to monitor their health at home to ensure no other signs of disease develop. However, if you are worried, there is no harm in seeking advice from your vet. Either talk to them about the issue at your kitty’s next check-up or call them sooner if it will help put your mind at rest.

MY FINAL THOUGHTS

So, why is your cat drinking a lot of water suddenly? If any other signs of illness don’t accompany your kitty’s excessive drinking, this behavior is probably due to an environmental change, such as an increase in temperature.

Monitor your feline so you spot anything concerning should it develop, and maybe mention the change to your vet the next time you see them to help with your peace of mind. However, if your kitty shows signs of illness on top of excessive drinking, it is probably the sign of a disease.

Make sure to keep an eye out for any possible symptoms and arrange an appointment with your vet as soon as possible so that they can give you a proper diagnosis. In many cases, treatment is highly effective, and you will see improvements in your feline’s health in no time. And if you’re unsure whether their increased drinking is normal or not, don’t hesitate to obtain a professional opinion.