Water is the nutrient dogs need most urgently and the one owners think about least. A dog can survive weeks without food and days without water.
The normal amount
Roughly 50 to 60ml per kilogram of body weight per day, or about an ounce per pound.
- 5kg dog: 250–300ml
- 15kg dog: 750–900ml
- 30kg dog: 1.5–1.8 litres
Treat these as the middle of a wide range. Hot weather, exercise, a dry-food diet, lactation and some medications all legitimately increase it. Dogs on wet food drink noticeably less, because roughly three quarters of their food is water.
The number that matters clinically: consistently over about 100ml per kilogram per day is considered excessive and warrants investigation.
Measuring it properly
If you are worried, measure rather than guess:
- Fill the bowl with a measured amount at the same time each day
- Top up with measured amounts
- Measure what is left 24 hours later
- Subtract, allowing for spillage and puddles outside
Do it for three days and take an average. In a multi-dog house you will need to separate them.
The ten-second dehydration check
Skin tent. Lift the skin over the shoulder blades and release. It should snap back instantly. Slow return suggests dehydration — though it is less reliable in very thin, very old or very overweight dogs.
Gums. Should be moist and slippery. Tacky or dry means dehydration.
Capillary refill. Press a finger on the gum until it blanches, then release. Colour should return within two seconds.
Eyes. Sunken eyes indicate significant dehydration.
More than one of these means a vet, not a bowl of water.
Why increased drinking matters so much
A sustained increase in thirst is one of the most useful symptoms in veterinary medicine, because it narrows the possibilities sharply:
- Kidney disease — very common in older dogs
- Diabetes mellitus — usually with weight loss despite a good appetite
- Cushing’s disease — with increased appetite, a pot belly and coat changes
- Pyometra — a uterine infection in unspayed bitches, usually weeks after a season. A surgical emergency
- Liver disease
- Hypercalcaemia, sometimes associated with certain cancers
- Medications, particularly steroids and diuretics
Most of these are far more treatable caught early.
If your dog has started drinking noticeably more, collect a first-morning urine sample in a clean container and take it with you. It tells your vet a great deal and it saves a visit.
The dogs for whom water is a priority
Kidney disease. Damaged kidneys cannot concentrate urine, so these dogs lose water constantly and must drink to compensate. Never restrict water, and wet food is genuinely therapeutic.
Bladder stone formers. Dilute urine is the single most effective preventive measure across all stone types.
Urinary tract infections.
Diabetic dogs, who lose water with glucose in the urine.
Older dogs generally, who are more prone to dehydration.
Dogs in hot weather, obviously.
Practical ways to increase intake
- More bowls, in more rooms, and outside
- Wet food, which substantially increases total water intake
- Add water to dry food, and let it stand
- A fountain. Some dogs drink considerably more from moving water
- Ice cubes in the bowl in summer
- Unsalted bone broth as a flavouring, in small amounts
- Clean bowls daily. Biofilm builds quickly and many dogs dislike it
- Stainless steel or ceramic rather than plastic, which scratches and holds odours
- A bowl that does not move. A non-slip base or a heavier bowl
- Water on every walk
Some links on this page are affiliate links. If you buy through them we may earn a small commission at no extra cost to you — it helps keep this site free. We only recommend products we would use with our own dogs.
PupFlask Dog Water Bottle
Bottle and bowl in one with a pour-back, so you can offer small amounts frequently without waste. For a dog who needs to drink more, having water available away from home is part of the plan rather than an extra.
XIAZ Elevated Dog Bowl Stand
For a dog with neck or elbow pain who finds bending to a floor bowl uncomfortable, a comfortable height genuinely increases how readily they drink. Not for deep-chested breeds, where raised feeders have been associated with increased bloat risk.
Water and exercise
After hard exercise, offer small amounts frequently rather than a bowlful at once.
A dog who gulps a large volume while panting swallows a lot of air, which causes discomfort and, in deep-chested breeds, is among the factors associated with bloat risk.
Let them cool a little, then offer water in stages.
Water intoxication
Rare, serious, and worth knowing about.
A dog who swallows a large volume of water — usually while repeatedly retrieving from water, or biting at a hose or sprinkler — can dilute their blood sodium dangerously, causing brain swelling.
Signs: wobbliness, vomiting, lethargy, bloating, glazed eyes, dilated pupils, collapse, seizures.
Prevention: limit water retrieving sessions, take breaks, use a flat floating toy rather than a ball that forces the mouth wide, and stop when a dog looks bloated.
Water to avoid
- Stagnant ponds and lakes, particularly in warm weather. Blue-green algae can kill within hours
- Sea water. Causes vomiting and, in quantity, dangerous sodium levels. Always take fresh water to the beach
- Puddles, ditches and slow streams — leptospirosis and giardia
- Puddles near roads, which may contain antifreeze
- Pool water, which irritates the gut
Restricting water
Almost never appropriate.
The one reasonable exception is lifting the bowl an hour or two before bed during puppy toilet training — and never in hot weather, never during the day, and never for a dog with any medical condition.
A dog with kidney disease, diabetes or Cushing’s must have water available at all times, however inconvenient the night-time toilet trips.
The habit worth building
Notice how often you fill the bowl.
Most owners never register a gradual change, because bowls get topped up without thought. A sudden change in how often you are filling it is information — and it is frequently the earliest sign of something worth catching.
