Water is the most overlooked part of pet nutrition. Unlike food, it has no label and no portion chart — so most owners simply don't know the number. A weight-based range fixes that.
Why water scales with weight
Body water turns over in proportion to size, so needs are roughly linear with weight: 50–70 ml per kg for dogs, 40–60 ml for cats. The range reflects that metabolic size and activity both shift the true need.
Food is a source too
Wet food is 70–80% water and can satisfy most of a cat's needs. Dry food is the opposite — a dog or cat on kibble needs nearly all its water from the bowl. The diet changes the effective target.
Reading the signals
The number matters less than changes in the number. Increased drinking can signal kidney or endocrine issues; refusing water in a sick pet is urgent. Baseline awareness of the typical range makes those signals visible.
Frequently asked questions
About 50–70 ml per kg of body weight. A 20 kg dog needs roughly 1–1.4 litres daily, more in heat or after exercise.
About 40–60 ml per kg — roughly 200–300 ml for an average cat. Wet food covers part of this, so bowl drinking is usually lower.
Cats drink less by nature and get water from wet food. Concern is less about the volume and more about a change in behaviour — sudden increases or decreases warrant a vet visit.