Cats are known for being low-maintenance drinkers. Most felines get a significant portion of their hydration from wet food and may not visit their water bowl too often. So, if you suddenly notice your cat drinking much more water than usual, it’s understandable to be concerned.
While increased thirst can be harmless in some cases, it can also be a sign of an underlying health issue that requires veterinary attention. Let’s explore the common reasons your cat may be drinking excessively, when to worry, and what you can do to help keep them healthy.
How Much Water Should a Cat Drink Normally?
A healthy adult cat typically drinks about 50–100 ml of water per kilogram of body weight daily. For example, a 5-kg cat should drink roughly 250–500 ml per day. However, factors such as your cat’s diet, daily activity, and living environment can affect this amount.
- Cats on dry food diets tend to drink more water because kibble contains only about 10% moisture.
- Cats on wet food diets may drink less since canned food has about 70–80% moisture.
- Hot or dry climates can also increase a cat’s water intake.
If you notice your cat visiting the water bowl more often, finishing it quickly, or even drinking from unusual places like the sink or toilet, it’s time to pay closer attention.
Possible Reasons Your Cat Is Drinking Excessively
1. Dehydration
Sometimes, your cat may become dehydrated due to excessive heat, increased activity, or a recent illness such as vomiting or diarrhea. Signs of dehydration include:
- Dry gums
- Lethargy
- Sunken eyes
- Loss of skin elasticity (skin doesn’t snap back quickly when pulled gently)
Ensure your cat always has access to fresh, clean water, and encourage drinking by using a cat water fountain or offering wet food.
Chronic kidney disease (CKD) is a frequent reason behind increased thirst in senior cats. As the kidneys lose their ability to filter waste effectively, they release more water, causing your cat to urinate and drink more often.
Other signs include:
- Weight loss
- Poor appetite
- Vomiting
- Bad breath (ammonia smell)
If you suspect your pet has kidney disease, consult your veterinarian immediately. Early diagnosis and special kidney-support diets can slow the disease’s progression.
3. Diabetes Mellitus
Just like humans, cats can develop diabetes, especially if they are overweight or middle-aged. High blood sugar causes the body to flush out excess glucose through urine, leading to dehydration and increased thirst.
Common symptoms:
- Frequent urination
- Weight loss despite a good appetite
- Lethargy
- Sweet-smelling breath
Your vet may perform blood and urine tests to confirm diabetes and recommend insulin therapy along with dietary changes.
4. Hyperthyroidism
Hyperthyroidism is a hormonal condition in which the thyroid gland produces excessive amounts of thyroid hormone. It’s common in cats over 10 years old.
Symptoms include:
- Increased thirst and urination
- Weight loss despite increased appetite
- Hyperactivity or restlessness
- Vomiting or diarrhea
This condition can be managed through medication, surgery, or a specialized diet under the guidance of a veterinarian.
5. Urinary Tract Infection (UTI) or Bladder Problems
Urinary tract infections or bladder irritation may cause your cat to urinate often, prompting them to drink extra water to stay hydrated.
Watch for:
- Straining or crying while urinating
- Blood in urine
- Urinating outside the litter box
These symptoms need immediate veterinary attention, as untreated urinary issues can quickly become serious.
6. Liver Disease
Cats with liver problems may show increased thirst due to metabolic imbalances. Additional symptoms often include:
- Yellowing of eyes or gums (jaundice)
- Vomiting or loss of appetite
- Lethargy
- Swollen belly
Blood tests and ultrasound imaging are typically needed to confirm liver disease and guide treatment.
7. Medications or Dietary Changes
Some medications, such as corticosteroids or diuretics, can cause your cat to drink and urinate more frequently. Likewise, certain high-salt or prescription diets may also increase thirst.
Always discuss any new symptoms with your veterinarian if your cat starts drinking excessively after a change in diet or medication.
When Should You See a Vet?
If your cat’s increased water consumption lasts for more than a couple of days, or is accompanied by other symptoms such as:
- Weight loss
- Vomiting
- Changes in appetite
- Lethargy
- Excessive urination
…it’s time to visit the vet.
Bring a note on how much water your cat is drinking, any changes in litter box habits, and details about their diet. This information will help your vet make an accurate diagnosis.
How Your Vet Will Diagnose the Cause
Your veterinarian may recommend the following tests:
- Blood tests to check liver and kidney function, blood sugar levels, and thyroid function.
- Urinalysis to detect infections, glucose, or protein in the urine.
- Ultrasound or X-rays to evaluate internal organs.
These tests help identify whether the issue is related to metabolic disorders, organ dysfunction, or infections.
How to Encourage Healthy Hydration
Regardless of the cause, keeping your cat well-hydrated is essential:
- Offer wet food regularly to increase fluid intake.
- Keep multiple water bowls around the house.
- Use a cat fountain — many cats prefer running water.
- Clean bowls daily to prevent bacteria buildup.
- Avoid plastic bowls, as they can hold odors and bacteria — stainless steel or ceramic is best.
Final Thoughts
While occasional extra drinking may not be a cause for alarm, persistent excessive thirst (polydipsia) should never be ignored. It’s often a sign of underlying conditions such as kidney disease, diabetes, or thyroid imbalance.
Prompt detection and timely treatment can significantly improve your cat’s well-being and help prevent potential health complications. Always monitor your cat’s behavior, eating habits, and litter box use — small changes can reveal a lot about their health.
If you’re ever unsure, consult your veterinarian for guidance. Being proactive about your cat’s hydration can help ensure they stay healthy, happy, and thriving.
