How Much Water Should Dogs and Cats Drink in a Day?
A commonly cited benchmark sits around fifty millilitres per kilogram a day — but diet, weather and disease all move the number.
Water intake is one of the easiest vital signs to track at home and one of the first to shift when something is wrong. A commonly cited benchmark is on the order of fifty millilitres per kilogram of body weight per day, but the figure moves with diet — wet food carries most of its weight as water — as well as with heat, exercise and age.
Measure it once — then watch for change
The practical method is not to chase a formula every day but to learn your animal’s baseline: fill bowls to a marked level, tally what disappears over a normal day or two, and remember that kibble-fed pets drink visibly more than wet-fed ones. Normal intake varies between individuals. Cats in particular tend to run dry — descended from desert hunters, many under-drink on kibble, which is why bowl placement, fountains and wet food matter for their urinary health.
What deserves attention is a sustained departure from that baseline. Drinking sharply more can accompany kidney disease, diabetes or hormonal disorders; drinking much less, especially alongside lethargy or vomiting, risks dehydration. If either pattern lasts beyond a day or two — or a cat stops drinking almost entirely — book a veterinary exam and bring your intake notes: the record turns a vague worry into data a clinician can act on.
MediIndex articles are for general information only and are not medical advice, diagnosis, or advertising. Outcomes vary by individual — consult a board-certified specialist for personal decisions.