The Liquid Breakdown of Your Feline Friend


Knowing how much liquid is in a cat is useful information for pet owners and veterinarians for several reasons. Proper hydration is crucial for a cat’s health and wellbeing. Monitoring your cat’s hydration level can help detect early signs of potential medical issues like kidney disease or diabetes. Understanding a cat’s normal hydration needs and range can also assist in maintaining their overall health and preventing dehydration, especially for kittens, senior cats, or sick cats.

Veterinarians rely on markers of hydration when examining feline patients as part of routine wellness checks or when diagnosing underlying illnesses. Changes in hydration status paired with other symptoms can aid vets in identifying and treating medical conditions. Additionally, calculating hydration helps vets determine appropriate treatment protocols and fluid therapy plans for dehydrated or hospitalized cats. For pet owners, regularly evaluating hydration can supplement veterinary care and enable timely interventions when abnormal hydration is noticed.

Total Body Water Percentage

Cats’ bodies consist of about 60-70% water, which is lower than some other mammals like humans, who average around 65% water (1). The percentage of total body water can vary between individual cats based on factors like breed, age, health status, and body condition.

For example, overweight or obese cats tend to have a lower percentage of body water compared to lean cats. Kittens also have a higher total body water percentage, around 75-80%, compared to adult cats (1). On the higher end, active outdoor cats may have total body water percentages reaching 75%, whereas more sedentary indoor cats are often in the 60-65% range.

Compared to dogs, who average 70% body water, and livestock like cows, who are nearly 75% water, cats have a lower overall fluid percentage by body weight (2). However, given their small size, cats still need a surprising amount of water each day to stay healthy.

Factors Affecting Hydration

A cat’s hydration levels can be affected by several factors including age, health conditions, diet, and activity level.

Kittens and senior cats tend to have higher water requirements than adult cats. Kittens need ample fluids to support growth and development. Meanwhile, older cats are more prone to kidney disease, diabetes, and other conditions that increase thirst.

Cats with health issues like kidney disease, diabetes, hyperthyroidism, or urinary problems need extra fluids to support their bodies. Medications like steroids can also increase thirst. Always follow your veterinarian’s guidelines for water intake if your cat has a medical condition.

Diet plays a major role in hydration. Cats fed canned food take in more moisture than those fed dry kibble. Make sure kibble-fed cats have constant access to fresh, clean water. According to Got Claws, cats only get ~30% of their water needs from dry food.

Activity levels impact thirst as well. Outdoor cats and those who are very active need more water to replenish fluids lost through panting and exertion. Cats who spend most of their time lounging indoors typically drink less.

Signs of Dehydration

Some telltale symptoms that a cat is dehydrated include dry mouth, sunken eyes, and lethargy. According to WebMD, a dry mouth is one of the first signs of dehydration in cats. Lack of hydration leads to reduced saliva production. You may notice your cat smacking its lips or excessive drooling. Cats also tend to lick their lips more when their mouths feel drier.

Sunken eyes or eyes that seem receded into the head can also indicate dehydration. This happens as the eyeballs lose moisture. The skin around the eyes may appear dry and wrinkled too. Lethargy and overall weakness is another symptom, as dehydration causes fatigue from low energy levels. Severely dehydrated cats may have trouble standing or walking normally.

Other signs include loss of appetite, fever, vomiting, diarrhea, rapid breathing, and poor skin elasticity. Use the “skin tenting” test by gently pinching and lifting the skin then releasing – if it’s slow to flatten out, the cat is likely dehydrated according to PetMD.

Measuring Hydration

There are a couple ways to check your cat’s hydration level at home:

Skin Elasticity Test

Gently pinch the skin on the back of your cat’s neck and pull it up to create a “tent.” Then let go. If your cat is well hydrated, the skin should snap back into place right away. If it stays tented for longer than 1-2 seconds before retracting, your cat may be dehydrated.

Packed Cell Volume

A packed cell volume (PCV) test measures the percentage of red blood cells in your cat’s blood. A blood sample is taken and spun in a centrifuge, which separates the red blood cells from the plasma. A higher PCV indicates dehydration, while a lower number can mean your cat is well hydrated.

Ask your vet to perform a PCV test if you suspect dehydration. They may recommend intravenous or subcutaneous fluids to rehydrate your cat if the PCV is high.

Daily Water Requirements

The amount of water a cat needs per day depends on several factors like weight, age, activity level, and health status. According to the CatBandit blog, the general rule is that cats should consume around 60 milliliters of water per kilogram of body weight daily.

For example, a 4 kg (8 lb) cat would need approximately 240 ml per day. Kittens and older cats need more water per kilogram of body weight. Very active cats or cats eating a dry food diet also require more water than the average cat.

Pregnant and nursing cats have increased water needs as well. Illness, especially kidney disease, can also increase daily water requirements. It’s important to monitor your cat’s water intake and adjust amounts as needed based on their individual needs.

Increasing Water Intake

There are several ways to encourage cats to drink more water and stay hydrated. According to this source, feeding wet food is an effective method, as it has a high moisture content. Cats tend to drink less water when being fed dry food. Switching to wet food or adding water to dry food can increase fluid intake.

Cat fountains are another great option. The flowing water encourages drinking, and cats seem to prefer running water to still water in bowls. Fountains come in plug-in and battery-operated models. They should be cleaned regularly to prevent bacteria buildup. Locating fountains away from food bowls can promote drinking.

Placing water bowls in multiple locations around the house can also remind cats to drink more frequently. Bowls should be located away from litter boxes and feeding stations to avoid contamination. Refilling frequently with fresh water also encourages drinking. Bowls can be elevated to be more noticeable.

Water Content in Food

Cats get a significant amount of their daily water intake from their food. There is a major difference in the water content between canned/wet food versus dry food.

According to Bond Vet, dry cat food contains an average of 6-10% water, while wet cat food may contain 70-85% water. Canned and pouched wet foods have a much higher water content than dry food.

As noted in Daily Water Requirements and Needs for Cats, canned diets usually contain about 75% moisture. So for every 100 grams of canned food fed, 75 grams (which equals 75 ml) is water.

This major difference in water content is important to consider when choosing between wet and dry food. Cats eating mostly dry food need to drink more water separately to stay hydrated. Wet food provides more moisture from the food itself.

When to Contact a Vet

In most cases, mild to moderate dehydration in cats can be treated at home by encouraging your cat to drink more water. However, if your cat is showing signs of severe dehydration, it is important to contact your veterinarian right away.

Some signs that indicate your cat needs urgent veterinary care for dehydration include:

  • Dry and tacky gums or tongue
  • Skin tenting – when the skin is pinched, it stays tented up instead of snapping back down
  • Sunken eyes
  • Weakness and collapse
  • Rapid heart rate
  • Rapid breathing rate
  • Low body temperature (below 100°F)
  • Not producing any urine

Severe dehydration can lead to potentially life-threatening complications like kidney failure, seizures, coma, and cardiac arrest. The quicker a severely dehydrated cat receives intravenous fluid therapy and supportive care, the better the chances of recovery. Call your vet immediately if your cat displays any advanced signs of dehydration.


Keeping your cat properly hydrated is extremely important for their overall health and wellbeing. Dehydration can cause serious complications if left untreated. By understanding your cat’s daily water requirements, being aware of signs of dehydration, and taking measures to increase their water intake, you can ensure your feline companion stays well-hydrated.

Cats have a low thirst drive compared to other pets, so they don’t drink as much water as they need. That’s why monitoring your cat’s hydration level is crucial. Their water intake can be increased by providing fresh, clean water at all times, adding more water bowls around your home, serving wet food, and adding water to their dry food. With proper care and attention, you can keep your cat’s fluid levels right where they need to be.

If you have any concerns about your cat’s hydration status, contact your veterinarian. They can perform examinations and tests to determine if your cat is dehydrated. Addressing any hydration issues quickly can prevent more serious health problems from developing. By staying vigilant and informed about your cat’s hydration needs, you can help keep them happy and healthy.

Scroll to Top