Cats and water: why wet food matters

If you have ever watched your cat at the water bowl, you may have noticed how little actually goes in. A few laps, a look around, done. Dogs drink like they mean it. Cats drink like they are being polite.

That is not a quirk of your cat. It is how cats are built, and it is the main reason wet food deserves a place in the bowl.

Cats are not big drinkers

Domestic cats descend from wild cats of dry regions, where water was scarce and most of it came from food. A mouse or a bird is roughly two-thirds water, so a hunting cat drinks very little and still stays hydrated.

Our cats kept the habit, but most of them no longer eat mice. A cat living on dry food alone gets very little water from its meals, and its thirst does not fully make up the difference. Many cats on a dry-only diet simply live slightly short of water, without showing any obvious sign.

How much water does a cat need?

A healthy adult cat needs roughly 40 to 60 ml of water per kilo of body weight per day, all sources included. For a 4 kg cat, that is about 160 to 240 ml: a large cup.

The key words are "all sources included". Water comes from the bowl and from the food:

• Dry food contains about 10% water. A day's worth of kibble brings only a few spoonfuls.
• Wet food is mostly water. Our fillets are 76% moisture, so a single 70 g tin brings about 53 ml, a quarter to a third of a 4 kg cat's daily need.

So the same cat can drink very little and be fine on wet food, or drink the same amount and fall short on kibble alone.

Signs your cat may need more water

Dehydration in cats is often subtle. Things to watch:

• very small or very dark urine clumps in the litter;
• dry or tacky gums;
• less energy than usual;
• constipation.

If you notice these, or if your cat suddenly drinks much more than usual (which can also be a sign of illness), talk to your vet. If your vet has ever mentioned urinary or kidney issues, more water is almost always part of the advice.

Wet food: the easiest win

You do not have to switch your cat to wet food entirely. Adding even one wet meal a day changes the water balance noticeably.

Some simple ways to do it:

• A tin on top of the kibble. Spoon a fillet over the usual dry food. The broth soaks in, the bowl smells better, and your cat gets water without noticing. Reduce the kibble a little so the total stays right; our feeding calculator does the maths.
• One wet meal, one dry meal. Many owners find this the most practical rhythm: wet in the morning or evening, kibble for the rest of the day.
• Do not throw away the broth. In our fillets, the meat or fish is cooked in its own broth. That liquid is not filler: it is water and flavour, and most cats lick it up first.
• A spoonful of water in the bowl. Warm (not hot) water stirred into wet food makes it smell stronger and adds a little more liquid.

Make the water bowl more tempting

Even with wet food, fresh water should always be available. Small changes can make a big difference:

• Wide and shallow. Many cats dislike narrow, deep bowls.
• Away from the food, and far from the litter tray. Many cats drink more when their water is not right next to their meal.
• More than one bowl. One in a quiet room, one where your cat likes to rest.
• Fresh every day. Cats notice stale water before you do.
• Moving water. Some cats prefer it. A pet fountain is worth trying if your cat drinks from the tap.

The same rules about bowls and calm corners help with appetite too: more in The picky cat: what actually helps.

In short

1. Cats are naturally light drinkers and rely on food for much of their water.
2. Dry food alone brings very little water; wet food is mostly water.
3. Adding one wet meal a day, or a tin over the kibble, is the simplest fix.
4. Keep the broth, offer fresh water in a wide bowl, away from food and litter.
5. If your cat drinks much more or much less than usual, ask your vet.

Your cat will not thank you for any of this. It will just quietly be better hydrated, which, for a cat, is about as close to gratitude as it gets.