Quenching Your Cat’s Thirst. Is Water Best for Kidney Disease?


Kidney disease is a common condition in cats, especially as they age. It occurs when the kidneys are damaged and can no longer effectively filter waste products from the blood. This results in the buildup of toxins in the body that can lead to symptoms like increased thirst, weight loss, vomiting, and lethargy.

One of the most important aspects of managing kidney disease in cats is ensuring proper hydration. When kidneys are damaged, they are not able to concentrate urine as effectively. This leads to increased urination and water loss from the body. Cats with kidney disease are at risk of becoming dehydrated, which can worsen kidney function and make them feel unwell. Drinking adequate water is essential to flush toxins from the body, maintain normal fluid balance, and support overall health.

Overview of Kidney Disease in Cats

Kidney disease is very common in cats, especially as they age. Studies show that chronic kidney disease (CKD) affects up to 30-50% of cats over 15 years old. The prevalence increases with age, but CKD can occur in cats as young as 1 year old.

There are several main causes of feline kidney disease. These include congenital abnormalities, infections, toxins, cancer, and most commonly age-related changes. As cats age, their kidneys undergo structural and functional changes that reduce the kidney’s ability to concentrate urine, regulate electrolytes, and perform other essential functions.

Kidney disease is classified into 4 stages based on lab tests that measure kidney function and markers in the blood and urine. Stage 1 is mild damage and stage 4 is end-stage kidney failure. Common symptoms such as increased thirst, weight loss, poor coat condition, vomiting, and fatigue typically start in stage 2.

Importance of Hydration for Kidney Health

Proper hydration is crucial for maintaining kidney health in cats. The kidneys act as filters to remove waste and toxins from the blood. In order to function properly, the kidneys require an adequate supply of water. Dehydration leads to the build up of waste products in the blood, placing additional strain on the kidneys.

According to Purina Institute, dehydration is a common complication of chronic kidney disease (CKD) in cats. When a cat becomes dehydrated, it can lead to loss of appetite, lethargy, weakness, constipation and increased susceptibility to urinary tract infections. Providing ample fresh water is essential to support kidney function.

The average cat should drink approximately 1 ounce of water per pound of body weight per day. For a 10 pound cat, that equates to around 10 ounces or 1 1/4 cups of water daily. Cats with kidney disease often need to consume even more water than average to help flush toxins from their system. Consulting with your veterinarian can help determine the ideal water intake for your individual cat.

Benefits of Drinking Water for Cats with Kidney Disease

Proper hydration is critical for cats with kidney disease. Increased water intake helps maintain hydration and provides several important benefits for kidney health:

Maintaining hydration and flushing toxins – Kidney disease causes the kidneys to lose their ability to concentrate urine. This means more water is lost through urination. Drinking more water helps counteract this loss of water and prevent dehydration. Increased water intake also helps flush toxins from the body that would otherwise build up when the kidneys are not functioning optimally (1).

Slowing disease progression – Even mild dehydration puts additional strain on damaged kidneys. This accelerates further loss of kidney function over time. Drinking adequate water reduces strain on the kidneys and helps slow the progression of kidney disease (2).

Reducing strain on kidneys – Vasopressin is a hormone that regulates fluid balance in the body. Higher vasopressin levels cause the kidneys to work harder to concentrate urine. Drinking more water reduces vasopressin secretion and takes some of the strain off of the kidneys (1).

(1) https://www.purinainstitute.com/centresquare/therapeutic-nutrition/maintaining-hydration-in-cats-with-ckd
(2) https://vcahospitals.com/know-your-pet/kidney-failure-chronic-in-cats

How Much Water Cats with Kidney Disease Should Drink

Cats with kidney disease need to stay well hydrated to support their kidney health. The recommended daily water intake for a cat with kidney disease is around 60ml per kg of body weight (Source: https://adelaidevet.com.au/pet-library/thirsty-cat-is-it-just-hot-or-is-something-up/). For example, a 4kg cat should drink approximately 240ml or one cup of water per day.

There are several tips to encourage your cat with kidney disease to drink more water:

  • Provide fresh, clean water at all times – change water bowls frequently
  • Use wide, shallow bowls so the water is more accessible
  • Consider getting a cat water fountain to provide running water
  • Add a bit of tuna juice or low-sodium broth to the water to increase palatability
  • Feed wet renal diets to increase moisture intake
  • Place water bowls around the house for easy access

Monitor your cat’s water intake daily. Notify your vet if you notice a decrease in drinking or urination, as that may indicate worsening kidney problems. With some creativity and patience, you can find ways to keep your cat well hydrated.

Providing Fresh, Clean Water

It’s important to provide cats with kidney disease access to plenty of fresh, clean drinking water. Water is essential for flushing toxins from the kidneys and preventing dehydration, which can worsen kidney problems.

Stagnant water can harbor bacteria, so it’s recommended to change your cat’s water daily. Use clean, sterile bowls and rinse thoroughly before refilling. Tap water from a clean source is fine for most cats.

Consider getting a cat fountain or allowing a faucet to drip to provide flowing water, which encourages drinking. The sound and movement of running water stimulates thirst. Place water bowls throughout your home so water is always within reach.1

Monitor your cat’s water consumption daily. Normal intake is around 3-4 ounces per pound of body weight. Increased thirst could signal kidney problems. Provide unlimited fresh water and contact your vet if intake changes.

Monitoring Water Intake

It’s important to monitor your cat’s water intake if they have kidney disease. This allows you to observe any changes and ensure they are staying hydrated.

Pay attention to how much water your cat drinks each day. Make note of how full their water bowl is in the morning and evening. You can also use products like SureFeed that track water consumption.

Watch for increased thirst or changes in drinking habits. Cats with kidney disease may drink more water to compensate for their decreased kidney function. If you notice your cat is suddenly drinking a lot more or less, contact your vet.

You should also let your vet know if you see signs of dehydration like lethargy, dry mouth, sunken eyes, or loss of skin elasticity. Dehydration can worsen kidney problems.

Frequent monitoring of water intake and alerting your vet to changes allows you to properly manage your cat’s hydration and kidney health.

Tips for Increasing Water Intake

There are several methods cat owners can try to encourage their cats with kidney disease to drink more water:

Flavoring water with tuna juice can make it more enticing for cats. The smell and taste of fish often prompts cats to drink. Make sure to use tuna packed in water, not oil. You can pour a small amount of the tuna water into your cat’s water bowl to give it more flavor. Replace daily to keep it fresh (https://vetprofessionals.com/site/downloads/free/Tips%20for%20encouraging%20your%20cat%20to%20drink.pdf).

Feeding wet food is another great way to increase water intake. Wet food has a high moisture content, so cats get additional fluids with every bite. Switching from dry to wet food or adding some wet food meals can be an easy change to boost hydration. You can also add extra water to wet food to create a “soup” consistency that some cats enjoy (https://www.purinainstitute.com/centresquare/therapeutic-nutrition/maintaining-hydration-in-cats-with-ckd).

Using wide, shallow bowls can encourage drinking since the water is more accessible. Bowls with flowing fountains also help keep the water fresh and appealing. Place water bowls throughout the house so there’s always one nearby (https://vetnutrition.tufts.edu/2020/12/tips-and-tricks-to-get-your-cat-to-drink-more-water/).

When to Talk to Your Vet

It’s important to monitor your cat’s water intake and contact your veterinarian if your cat is not drinking enough water. According to Cornell University College of Veterinary Medicine, cats should drink around 2.5-3.5 ounces of water per pound of body weight per day. For a 10 pound cat, that’s 25-35 ounces or about 3-4 cups of water daily.

If your cat is not consuming the recommended amount of water each day, let your vet know right away. Inadequate hydration can exacerbate kidney problems and lead to further kidney damage. Your vet may recommend switching to a prescription kidney diet, administering subcutaneous fluids, or other interventions to increase hydration.

Also contact your vet if you notice your cat’s kidney disease seems to be progressing – common signs include increased thirst, more frequent urination, weight loss, poor appetite, nausea/vomiting, and lethargy. Your vet can run tests to determine if kidney function is declining and if adjustments to treatment are needed.

Monitoring water intake daily and being vigilant about changes is crucial for cats with kidney disease. Don’t hesitate to call your vet with any concerns about hydration or worsening kidney problems.


Hydration is critical for cats with kidney disease. Drinking adequate water helps flush toxins from the body, prevents dehydration, maintains healthy blood flow, and supports overall kidney function. Cats with kidney disease should have fresh, clean water available at all times. Monitor your cat’s water intake and aim for them to drink the equivalent of at least 2.5 ounces per pound of body weight per day. Providing multiple water stations, flavoring water with tuna juice, using cat fountains, and feeding wet food can all help increase water consumption. Work closely with your veterinarian to determine the right hydration goals for your individual cat. With proper monitoring and care, many cats with kidney disease can live long and comfortable lives.

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