Do you notice the presence of polydipsia (an increased water intake) in your cat recently? Well, the answer should lie either in simple environmental changes or health-related severe problems. Here are the possible explanations to your question of “Why is my cat drinking a lot of water?”.

We – humans, drink water when we feel thirsty and to compensate for the amount of water loss after eating dry food or exercising. Cats are just the same, they also drink water to quench the thirst and to fulfill the lost fluid in their body.

However, besides environmental elements such as your cat’s diet or the weather, excessive thirst in cats can be caused by certain medical conditions and can lead to some fatal diseases. So when you see your cat drinking a lot of water suddenly, especially when the polydipsia is coupled with vomiting or losing weight, carefully check with your vet.

Is my cat drinking too much water?

First of all, it is very important to know whether your cat is really drinking too much water or not. In order to do this, you should know the normal amount of water intake for cats in a day and the signs showing that your cat is having an abnormal thirst.

How much water should a cat drink?

Each cat is different, so their water intake varies depending on their health, lifestyle and living environment.

For example, a cat eating only dry food should drink more than a cat eating wet food or an energetic cat who spends the day outdoor should drink more than an indoor cat.

However, on average, a domestic cat should drink around 45ml/kg/day or 4 – 5 ounces/day (this also includes water cats receive in food). So, if your cat weighs about 5 kg, then he should intake about 225ml/day. Don’t forget to take your cat’s diet and personality into consideration before jumping into the conclusion that he is drinking too much.

How to know if my cat is drinking too much water?

Of course, it is best to visit the vet and run a series of urine tests to calculate the exact difference between the amount of water intake and excreted.

However, there are some signs in cats that are easy to notice as well as some methods of measurement that you can try at home. 3 main signs that your cat is drinking more water than usual:

  • More sudden trips to the water bowl and you need to refill the bowl more often
  • An increase in urination frequency (in the litter box or accidents around the house)
  • Unusual drinking from other sources such as taps, shower, etc. (only if he has never done it before)

You can also use water cups with measurements to measure the amount of water you fill in the bowl and the amount of water your cat drinks. However, this method only works if your cat is the only drinker of the bowl (in case you have more than one cat), and he is not drinking from any other sources.  

Why is my cat suddenly drinking a lot of water?

Lifestyle and environmental causes

As aforementioned above, if you notice your cat drinking a lot of water suddenly, try thinking about his diet, habits, and surroundings first. Is it summer and the weather is very hot? Or is your house is too warm? Do you only feed him dry food? And has he been spending a lot of time outside?

Well, hot weather and physical activities naturally lead to excessive thirst, while a dry diet also leads to your cat drinking more water to compensate for the lack of water in their meals. So if you can put your cat’s increased water intake down to these factors, there is no need to panic.

Underlying diseases

On the other hand, cats can be very good at covering up their illness. So if you notice your cat drinking a lot of water and losing weight, not eating/eating more, being inactive, or peeing a lot, it could be the symptom of some underlying diseases that could affect his life if not diagnosed and treated on time. 

4 health-related causes for excessive water intake

Diabetes mellitus

Feline diabetes is diagnosed with high sugar levels in the blood, and when the sugar spills out into the urine, it carries large volumes of water. Increased thirst is one of the early signs of feline diabetes mellitus, other signs you should watch out for consist of excessive urination, increased appetite, and sudden weight loss. If you notice from 2 out of all these symptoms, take your cat to the vet to do urine and blood tests.

Chronic kidney disease

Feline kidney disease occurs when one or both kidneys fail to maintain the body’s water balance. This results in your cat drinking a lot of water to keep the hydration balance. Other than drinking more water, your cat might also eat less, lose weight, vomit or experience diarrhea. Simple urine and blood tests can indicate feline kidney disease.  


Hyperthyroidism (overactive thyroid) is very common in cats, it can affect heart rate and blood pressure. Early symptoms include an unquenchable thirst, large appetite, excessive urination, sudden hyperactivity, and vomiting. Hyperthyroidism can also be diagnosed with simple blood tests. 

Urinary tract disease

If your cat is experiencing a urinary tract disease, she is in pain, so it is not that difficult to notice. If you notice your cat suddenly drinking a lot of water, licking his genital after peeing and blood in the urine, then he is in great pain and is having serious health-related problems that should be checked by the vet immediately.  

After all, what should I do when my cat is drinking a lot of water?

In conclusion, it is best to take your fluffy baby to the vet for urine and blood check-ups if you are wondering, “why is my cat drinking a lot of water?”. Bear in mind that the above-mentioned diseases are common in older cats, so if you notice your old cat drinking a lot of water suddenly, it is more likely that they are sick. So taking him to the vet for timely diagnosis and treatment is advised.  


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