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Why Is My Cat Drinking More Water Than Usual?
Common causes of increased thirst in cats, and why it's worth taking seriously.
Quick Answer
- A diet change, hot weather, or more exercise can cause a mild, temporary increase in thirst.
- A noticeable, ongoing increase is more often linked to an underlying condition, especially in older cats.
- Kidney disease, diabetes, and an overactive thyroid are the most common medical causes.
- Increased thirst rarely needs an emergency vet visit on its own, but does warrant a vet check.
Common Causes of Increased Thirst in Cats
01 Diet Change
Cats on a mostly dry food diet naturally drink more water than those eating wet food, since wet food already contains a high proportion of moisture. Switching diets can cause a noticeable, harmless change in water intake.
02 Hot Weather or Increased Activity
Warmer weather or a more active lifestyle can increase a cat's natural thirst, similar to how people drink more water when it's hot or after exercise.
03 Kidney Disease Common in older cats
Kidney disease is one of the most common causes of increased thirst in older cats. As kidney function declines, cats often drink and urinate more to compensate, sometimes alongside weight loss or a change in appetite.
04 Diabetes Mellitus Needs a vet
Diabetes can cause excessive thirst and urination, often alongside an increased appetite but ongoing weight loss. This needs proper veterinary diagnosis and management.
05 Hyperthyroidism
An overactive thyroid gland is relatively common in older cats and can cause increased thirst, increased appetite, and weight loss despite eating more.
06 Urinary Tract Issues
Some bladder or urinary conditions can change how much a cat drinks and urinates, sometimes alongside straining or changes in litter tray habits.
When to Contact Your Vet
- You notice your cat drinking noticeably more than usual over several days
- Increased thirst is alongside weight loss, increased appetite, or lethargy
- Your cat is urinating more frequently, in larger amounts, or outside the litter tray
- The change in thirst affects an older cat, where underlying conditions are more common
How Pet Med Direct Can Help
Pet Med Direct stocks specially formulated diets that can support cats with certain kidney or urinary conditions, as recommended by a vet.
If your vet diagnoses kidney disease, diabetes, hyperthyroidism, or another condition needing ongoing medication, Pet Med Direct can help with prescription dispensing once your vet has issued a valid prescription.
Some treatments require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet's advice and the directions on the medicine label.
Frequently Asked Questions
How much water should a cat normally drink?
This varies depending on diet, activity, and the weather, so it's more useful to watch for a noticeable change from your cat's normal pattern rather than aiming for a specific amount.
Is increased thirst always a sign of a health problem?
Not always — diet, weather, and activity can all play a role. However, a clear, ongoing increase, especially in an older cat, is worth getting checked rather than assumed to be harmless.
What tests might my vet do?
Your vet will likely suggest blood and urine tests to check kidney function, blood sugar, and thyroid levels, since these are the most common underlying causes of increased thirst in cats.
Can stress cause a cat to drink more water?
Stress is not a typical direct cause of increased thirst in cats, so a noticeable change is more likely linked to diet, environment, or an underlying medical condition.
Should I restrict my cat's water if they're drinking a lot?
No. Never restrict water access, even if your cat is drinking more than usual. Speak to your vet to find out why, rather than limiting their intake.
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This this article is for informational purposes only and does not constitute veterinary advice.
If you are concerned with your dog’s health, please consult a qualified veterinarian.
If you are concerned with your dog’s health, please consult a qualified veterinarian.