Why is My Cat Drinking So Much Water? The Top Causes Explained

Cats aren't always known for being big water drinkers, so it can be alarming when your feline friend suddenly starts drinking more than usual. While a hot day or switching to dry food might explain a temporary increase, consistently excessive thirst is never something to ignore in cats. Increased thirst, or polydipsia, can be the first sign of serious health issues, including kidney disease, diabetes, hyperthyroidism, and more. Paying attention to your cat's drinking habits is important for early diagnosis and successful treatment. Let's explore why your cat might be drinking so much water and when it's time for a vet visit.

How much water is normal for a cat?

While there's no definitive "perfect" amount of water for all cats, a general guideline is approximately 30 ml of water per kilogram of body weight per day (24 hours). This number refers to the amount of water consumed from actual drinking, not from dietary sources.

It's important to remember that cats naturally obtain the majority of their fluids via their diet, especially if they eat wet food.

Here's why variations occur:

• Diet: Cats eating mostly wet food get significant hydration from their meals and may drink less from their water bowl.
• Activity Level: Very active cats or outdoor cats might need slightly more water.
• Health: Age and medical conditions such as dehydration can change your cat's water consumption.

What does excessive thirst in cats look like?

Noticing increased thirst in your cat isn't always as simple as watching them drink more from their bowl. Here are the changes to look for:

• Emptying the bowl quickly: If you find yourself refilling their water bowl much more frequently than normal, it's worth investigating.
• Seeking out unusual water sources: Does your cat suddenly show interest in dripping faucets, toilets, or even puddles?
• Changes in urination: Increased thirst usually leads to increased urination. You might notice a fuller litter box or even your cat urinating in different locations outside the litter box.

Tracking your cat's water intake:

If you suspect your cat is drinking more, a simple test can help:

1. Measure how much water you put in their bowl daily
2. After 24 hours, measure how much water is left
3. Do this for several days to establish their average intake

This baseline will be useful information for your veterinarian.

The most common medical causes of increased thirst in cats (polydipsia)

If you notice your cat suddenly drinking lots of water, it's often a sign of an underlying medical problem. Here are some of the most common culprits:

1. Chronic Kidney Disease (CKD): Failing kidneys lose the ability to concentrate urine, leading to excessive water loss through urination. To compensate, cats with CKD drink significantly more. This should be suspected in any senior cat with progressive weight loss and normal to reduced appetite.
2. Diabetes Mellitus: In cats with diabetes, high blood sugar levels spill into the urine, drawing water with it. This results in dehydration and increased thirst as the body tries to rebalance fluids. This should be considered in any middle-aged, overweight cat with excessive thirst and appetite.
3. Hyperthyroidism: An overactive thyroid gland boosts metabolism in cats, making them feel hot, restless, and thirsty. Increased thirst is a common early sign of hyperthyroidism. This condition should be suspected in senior cats with progressive weight loss, increased levels of activity, and increased appetite.
4. Postobstructive Diuresis: This occurs after a urinary blockage has been treated and resolved. Sometimes after treatment, excessive solutes are urinated out which can lead to more water loss in the urine, which leads to increased thirst.
5. Iatrogenic Causes: Certain medications, like diuretics or steroids, can increase thirst as a side effect. If your cat starts drinking excessively after starting a new medication, consult your veterinarian.

Important Note: These are just some of the potential causes of increased thirst in cats. If you notice this change in your pet, it's essential to get them examined by your veterinarian to determine the underlying cause.

When is increased water consumption a medical concern?

While increased thirst alone warrants a vet visit, certain accompanying symptoms signal the need for more urgent care. Watch for these red flags:

What to expect at your vet appointment

If your cat is drinking excessively, your veterinarian will take a thorough approach to pinpoint the cause. Here's what the process typically involves:

• Detailed history: Your vet will ask questions about your cat's water intake, any other changes (behavior, appetite, urination), and their overall health history.
• Physical exam: Your vet will give your cat a full check-up, looking for signs of of dehydration, organ changes during the abdominal palpation, and assessing the body condition for example.
• Bloodwork: A blood test screens for underlying issues affecting organ function, like kidney disease, diabetes, and thyroid problems.
• Urinalysis: Analyzing a urine sample is essential, as it reveals how concentrated your cat's urine is and can check for signs of infection or diabetes.
• Further diagnostics: Depending on the initial findings, your vet might recommend additional tests, such as an ultrasound or X-rays, for a more detailed assessment.

Finding the answers: By combining the information gathered from your cat's history, examination, and test results, your veterinarian will work to diagnose the reason behind their increased thirst. This paves the way for appropriate treatment and management.

Don't underestimate the significance of increased thirst in your cat. While it could stem from something minor, it's vital to rule out serious health conditions. Pay close attention to your cat's drinking habits and any changes that occur. By working closely with your veterinarian, you can find the cause of your cat's excessive drinking and get them the help they need to feel their best again.