Why is my cat so thirsty?

When your cat changes their drinking habits, pay attention. Increased or decreased thirst can point to health problems in your feline friend. We’ve compiled information on common questions about why your cat is so thirsty and how much water they should drink. When in doubt, we advise talking to your veterinarian to ensure your cat is happy and healthy. Let’s learn more about cats and drinking water!

How much water should cats drink?

Some cats drink more water than others, but most don’t drink nearly enough. Some owners even have to get creative to encourage their feline friends to stay hydrated. Using a water fountain or incorporating wet food into the diet can help.

Generally, a cat should drink about ½ cup of water per 5 pounds (lbs) or roughly 120 milliliters (mL) per 2.3 kilograms (kgs) of body weight.

Factors that affect how much a cat drinks

Not all changes in a cat’s thirst are abnormal. One major factor that affects thirst in cats is changes in their food. Switching from wet to dry food may increase thirst while the opposite may decrease thirst. Wild cats primarily get enough water from their prey, unlike house cats, who depend on us to make sure they’re getting enough water.

Cats may increase their water intake when it’s hot outside (just like us). If it’s hot or dry, make sure your cat has access to plenty of fresh water and a cool place to rest. Your cat will likely return to their normal drinking habits when the weather cools down. Keep in mind that cats that drink more pee more. Watching your cat’s litter box closely can alert you to changes in thirst.

Causes of excessive thirst in cats

Take note if your kitty is making more trips to the water bowl than usual or drinking from strange places (like the sink, toilet, or even your cup). If there haven’t been any weather or food changes, there might be a health issue to blame. Some problems to consider include:

• Diabetes mellitus. Usually accompanied by a severe increase in urination, diabetes is common in obese cats. Other symptoms include decreased appetite, lethargy, and chronic infections. Insulin injections or, more recently, oral medications  are used to treat diabetes in cats.
• Kidney disease. When cats develop kidney disease, the kidneys lose some of their ability to remove waste products from the body. They may also lose the ability to concentrate urine properly. So, the cat’s instincts tell them to flush their body with fluids to compensate.
• Liver disease. Like kidney disease, liver disease and liver failure tend to drive cats toward increased water intake. However, liver disease often results from other conditions (Trusted Source) . Depending on the cause and level of function loss, liver disease can often be managed with medication, food changes, and fluid therapy.
• Hyperthyroidism. The result of too much thyroid hormone circulation through the body, hyperthyroidism typically causes increased drinking, peeing, and appetite in cats. Many hyperthyroid cats become ravenous, eating everything they can while continuing to lose weight.
• Urinary tract infection. As with humans, urinary tract infections (UTIs) cause discomfort and urgency to pee in cats. The cat’s instinct to flush their body takes over, increasing drinking. Cats with a UTI may also pee outside their litter box due to painful urination.
• Medication side effects. Some medications such as steroids (Prednisolone, dexamethasone, triamcinolone, etc.) and diuretics (furosemide, bumetanide, torsemide, etc.) cause increased thirst and urination. If the side effects are severe, your vet may stop the medication or provide additional medications to ease the side effects.
• Dehydration. A lack of access to water or refusal to drink can result in dehydration and increased thirst. Some signs of dehydration include sunken eyes, lethargy, dry mouth, pale gums, panting, and refusal to eat. Dehydration can be a symptom of the above problems, too. Thankfully, your vet can usually treat dehydration with fluid therapy.
• Heat exhaustion. If your cat has been exposed to high temperatures (especially those at or above 80°F), they could be experiencing heat exhaustion. Heat illnesses often accompany dehydration, meaning your cat will likely drink more water than normal. This condition can be quite serious and requires immediate medical attention.

When to take your cat to the vet for excessive thirst

If your cat’s increased thirst isn’t linked to changes in diet or weather, it’s time to dig deeper. Call your vet immediately if you notice additional symptoms like weight loss/gain, lethargy, changes in appetite, drooling, panting, or any others listed above. Some of these changes can be life-threatening if not addressed quickly.

🚨 Note that if your male cat suddenly cannot pee, this is an EMERGENCY. Urinary blockages in male cats can result in an increase in electrolytes in the blood, rupture of the bladder, and even death.

How vets diagnose and treat very thirsty cats

Diagnosing a very thirsty cat can be tricky. Your vet will likely start with a thorough exam and ask about the changes you have noticed. Next up, blood work and a urinalysis. If those don’t provide a solid answer, the vet may request X-rays or an ultrasound.

Depending on the source of the problem, your cat may need medication. Some concerns (like UTIs) require a brief round of antibiotics, while others (like diabetes and hyperthyroidism) will require life-long treatment and monitoring. Regardless of the cause, your vet will help you determine how to resolve your cat’s thirst.

Changes in drinking water may be normal for some cats during certain times of the year or due to changes in food. However, some changes alert you to medical issues that need addressing quickly. Pay close attention to your cat’s water intake and take notes whenever it changes. When in doubt, a quick call or visit to the vet is a safe bet to ensure your cat stays happy and healthy.

Frequently asked questions

Why is my cat not eating but drinking lots of water?

This change in drinking can be associated with weather changes. When it’s hot, dry, or humid out, we drink more water. So do cats. Another reason might be that you changed your cat’s food to something that contains less moisture, and they need to compensate by drinking more.

Can increased thirst be a sign of stress and anxiety in cats?

While not the most common sign of stress or anxiety in cats, an increased thirst could mean your cat is uncomfortable. Take a look at your kitty’s surroundings. Did things change dramatically, such as with a move or introducing a new pet? If so, your cat may be afraid to come out and drink. If everything’s relatively the same, consider there may be an underlying health concern.

Do cats drink more water as they get older?

Getting older isn’t a direct reason for drinking more water in cats. However, several disease processes can occur in older cats that could explain increased thirst.

When should I be concerned about my cat drinking a lot of water?

If your cat’s increased thirst is accompanied by other symptoms like lethargy, urinating outside the box, vomiting, diarrhea, weight changes, etc., call your vet immediately.

How do I know if my cat is drinking enough water?

The average 10 lb cat should drink about 1 cup of water a day. If you’re feeding your cat wet food, they will likely drink less. If you’re concerned about your cat’s thirst, seek vet advice.