Daily water for dogs and cats
Enter your pet's weight: get how much water it should drink in a day, with the normal range.
What it's for
Dogs and cats need 44-66 ml of water per kg of body weight per day, according to the Merck Veterinary Manual: the page gives the middle of that range, 55 ml per kg, and the whole range. Monitoring intake helps you spot problems early.
Warning
If your pet persistently drinks much more or much less than normal, talk to your vet: it can signal something worth checking.
The number changes a lot with what they eat
Those 44-66 millilitres per kilo are the total water requirement, not what has to be drunk from the bowl. Wet food is 70-80% water, so an animal eating tins covers much of its needs through meals and drinks far less; one eating only dry food (10% water) has to take almost all of it from the bowl. A dog moving from wet to dry suddenly drinks twice as much, and that isn't a symptom: the diet changed.
Cats drink little by design
The domestic cat descends from a desert animal and has kept a weak thirst: it doesn't compensate well at the bowl for what it doesn't get from food, which is why chronic dehydration and urinary problems are so common in cats fed only dry food. Three things really work: some wet food in the diet, wide, shallow bowls (whiskers touching the sides are unpleasant) and moving water, that is a fountain, which a great many cats clearly prefer.
It also helps to put the water away from the food bowl and in several places around the house: it's a habit that comes from behaviour in the wild, where the water source and the eating place don't coincide.
When the change is a signal
The change matters far more than the absolute value. An animal that starts drinking much more than usual, persistently and without a change of diet or season, is the commonest warning sign for diabetes, kidney problems and some hormonal diseases, and often the first sign, while it still seems well. The opposite counts too: an animal that stops drinking should be seen at once.
The way to notice is trivial and nobody does it: measure for two or three days how much goes into the bowl and how much is left. A number written on a scrap of paper is worth more than «I think it's drinking a lot», and it's also what the vet will ask for.
Nearby tools
For daily calories there are Dog calorie needs and Cat calorie needs, and for grams of food Daily kibble amount. For the foods to keep away Foods dangerous for pets.