When to Call the Vet About Your Cat's Water Intake
Published: October 31, 2026
Most cats that drink a little less than usual are fine, especially cats that eat wet food. Changes in drinking can also be an early sign of illness, though. This guide sorts the signs into three groups so you know whether to watch, call, or go now.
Quick guide
| What you see | What to do | How soon |
|---|---|---|
| Dry or sticky gums, slow skin return, or not eating and drinking for a day | Call your vet | The same day |
| Vomiting or diarrhea that lasts more than a day | Call your vet | The same day |
| Drinking much more than usual, or much less, for several days | Book a check-up | Within a few days |
| Drinking a little less, but eating, playing and using the litter box normally | Offer fresh water and wet food, then watch | Re-check in 24 hours |
The table is a general guide. If you are unsure, calling your vet is always reasonable.
Drinking more than usual
A cat that suddenly drinks much more can have a health problem such as kidney disease, diabetes or an overactive thyroid. This is not something to wait out. Note how much your cat drinks and how often it uses the litter box, then see why a cat may drink so much water and book a visit.
Drinking less than usual
Cats that eat wet food often drink very little from the bowl, and that can be normal. A cat that is drinking less and also eating less, hiding or looking tired is different. Cornell Feline Health Center lists lethargy, weakness, poor appetite, dry gums and sunken eyes among the signs of dehydration. For simple ways to encourage drinking, see how to hydrate a cat at home.
Cats that need earlier help
Call sooner rather than later for kittens, senior cats, and cats with kidney disease, diabetes or hyperthyroidism, because they can become dehydrated more easily.
What to tell the vet
- How long the change has lasted
- Eating, drinking and litter box habits, including any change in urine clumps
- Any vomiting, diarrhea, new medicine or new food
- Your cat's age and any known conditions
Nights and weekends
If your regular clinic is closed, ask for its out-of-hours number, or find the nearest emergency vet. Phoning ahead lets them prepare and tell you whether to come in. There is more in what to do if you suspect dehydration at night or on a weekend.
This article is general information, not veterinary advice or a diagnosis.
- Hydration, Cornell Feline Health Center, Cornell University College of Veterinary Medicine
- How to encourage your cat to drink, International Cat Care
This page is written in our own words from general information. It is not veterinary advice. If you think your cat is unwell, contact your vet.