Why Does my Cat Drink a Lot?


For the second time that day you pick up the cat’s empty water bowl. As you run the faucet, a voice nags in your head that the cat never used to drink so much. This worries you and a bad feeling settles in the pit of your stomach. You ought to get the cat checked by a vet, but you dread to hear this is the beginning of the end and nothing can be done…



Put all such negative thoughts aside and know that thirst is an important symptom of several conditions, the majority of which are treatable. Indeed, timely therapy could extend your feline friend’s life expectancy by years (yes years!)


What’s a Normal Amount for a Cat to Drink?

The ancestors of our domestic cats were desert dwellers. With little or no water amidst the arid sand dunes, these ancestor cats evolved superbly efficient kidneys, which harvested vital water from the body tissue of their prey.

This is why it’s unusual to see a healthy cat that eats canned food, drinking water. Their kidneys are so good at recycling that they get what they need from the moist food. (Of course fresh water should be available at all times.)

However, switch kitty onto dry kibble and you’ll start to see them drink. The reason is that biscuit contains very little moisture (as low as 10%) in contrast to canned foods which are a staggering 75% water. Hence, if you recently switched your four-legger from wet to dry food, panic over! They’re likely just drinking more to make up for the lack of water in their diet.


Signs your Cat is Drinking More

OK, if your cat is drinking more and you’re not sure whether it’s diet related, take a look at their litter box habits. The cat that’s thirsty because of a diet change won’t alter their litter box habits. A cat that is thirsty for health reasons will produce a small flood of puddles, so keep an eye out for soggy litter boxes.

If you find yourself:

  • Refilling the water bowls more frequently
  • Emptying more wet litter from the tray

Then your cat has increased thirst and you should check in with a vet.


Possible Reasons your Cat Drinks a Lot

Well done! You’ve booked a vet appointment, but you’re still worried about what the diagnosis might be. What sort of problems might you be looking at? Here’s a quick rundown of some of the commonest causes of increased thirst.

#1: Infection

Some cats with a bacterial infection will drink more so as to flush toxins out of their system. This is often associated with the cat being off-color and eating less. Your vet will check the cat’s temperature and possibly run some blood tests. The good news is that a course of antibiotics may be all that’s needed to get kitty back on her paws.

#2: Kidney Disease

Kidney disease is common and affects one in two cats over the age of 15. The signs include increased thirst, weight loss, poor appetite, and vomiting.

However, early diagnosis and therapy make it perfectly realistic to slow down the deterioration (and maybe even improve renal function) so the cat goes on to lead a long and happy life. Indeed, there’s a new blood test called SDMA which allows vets to spot kidney disease months or years earlier than was previously possible. The earlier treatment starts, the better the long term outlook.

Remember, simple changes in diet plus starting medication if necessary, can make a dramatic difference to the life expectancy of cats with mild to moderate kidney disease, and the latter is not a diagnosis to be fearful of.

#3: Sugar Diabetes (Diabetes Mellitus)

Approximately one in every 400 cats suffers from sugar diabetes. This is similar to Type II diabetes in people where the body either doesn’t produce enough insulin or the body’s cells are resistant to its action. This leads to raised blood sugar levels, which makes the cat drink more in order to dilute the excess sugar.

The symptoms include excessive thirst, often accompanied by weight loss. Some cats develop a strange way of walking, with “flat feet” at the back, and in advanced diabetes the pet might develop cataracts and their breath smell like nail-polish remover.

Diabetes is treated with diet changes and insulin injections. When treated early, scientific studies show anywhere between 17 – 67% of cases go into remission and no longer need insulin therapy. Therefore it’s much better to tackle the problem head-on and seek help, rather ignore your cat’s thirst and hope it will go away of its own accord. Indeed, the longer the diabetes goes untreated, the greater the risk of complications.

#4: Over Active Thyroid Glands (Hyperthyroidism)

This common condition is caused by the thyroid glands producing too much thyroid hormone. The latter regulates the body’s metabolic rate and too much thyroid hormone is a bit like driving a car with your foot flat on the gas pedal, everything happens too fast.

The typical symptoms include thirst, a ravenous appetite, and being hyperactive. When left untreated complications will develop such as heart failure, liver disease, and high blood pressure (often leading to blindness).

A number of highly successful therapies are available, including:

  • Diet: Hills YD food is iodine restricted which means the body isn’t oversupplied and therefore cannot manufacture too much hormone.
  • Medication: Pills are widely available with counteract the excess thyroid hormone
  • Surgery: To remove the overactive glands
  • Radioactive iodine: This is the gold standard treatment where the overactive tissue is selectively destroyed after an injection of radioactive iodine.


Water as Therapy


And finally, whatever the reason for drinking a lot, your cat should have access to plentiful fresh water at all times. Indeed, conditions such as kidney disease positively benefit from encouraging the cat to drink. With this in mind provide multiple water bowls around the house. But if your cat is fussy about drinking from bowls and prefers a dripping tap, a pet water fountain is a great choice in order to keep your feline friend fully-hydrated, fit and healthy.