How Much Water Should my Dog Drink?

You've just topped up the water bowl for the third time before lunch, and you're wondering: is my dog drinking too much, too little, or exactly the right amount? If that sounds familiar, you're not alone — it's one of those everyday puzzles that quietly worries a lot of pet parents, especially in hot weather or when your dog's drinking habits suddenly change.

The good news is it's usually simpler than it feels. Below you'll find how much water your dog should drink each day, what nudges that number up and down, the signs of a dehydrated dog to watch for, and when a change in drinking water is worth a chat with your vet.

How much water should a dog drink a day?

As a general rule of thumb, a healthy dog needs around 50 ml of water per kg of body weight per day — most dogs sit in the 40–60 ml per kg range. Water helps every part of your dog's body function properly, from cushioning joints to carrying nutrients, so getting enough water genuinely matters, just as it does for humans.

Here's roughly what that works out to, using body weight as your yardstick:

• Small dogs (around 5 kg): roughly 250 ml of water a day — think a Chihuahua or a small terrier.
• Medium dogs (around 10–20 kg): between 500 ml and 1 litre a day, covering breeds like Cocker Spaniels or Border Collies.
• Larger dogs (around 30 kg): about 1.5 litres a day, where many Labradors and Retrievers land.

If you'd rather not do the sums yourself, a quick online water intake calculator will estimate a target from your dog's weight and activity level. Just remember these figures describe your dog's total daily water intake — some of which comes from what your dog eats, not only the bowl.

How much water should a puppy drink?

Puppies drink little and often — small amounts frequently — rather than in big gulps, and their needs shift quickly as they grow and get more active. Once they're weaned onto solid food, offer constant access to clean water and keep a closer eye on things, because a wobbly, developing pup can tip into dehydration faster than a sturdy adult. If your puppy seems to be drinking a lot more or a lot less than usual, it's always worth a quick word with your vet.

What affects how much your dog drinks

Two dogs of the same size can drink quite different amounts, and that's completely normal. A few everyday factors nudge that daily figure up and down:

• Activity level and exercise: a dog who's had a long, muddy adventure needs more water than one who's mostly snoozed on the sofa — more exercise means more panting, and more water loss to replace.
• Hot weather: panting is how dogs regulate their body temperature, so in hot weather they lose fluid quickly and naturally drink more. Expect to refill the water bowl more often.
• Diet: dogs on wet dog food or raw food take in a lot of moisture — canned and wet food can be 65–80% water — so they often drink less from the bowl. Dogs on mostly dry food get little from dinner, so a dry diet usually means they top up more at the bowl.
• Age: older dogs can go either way — some drink more with older age or certain health conditions, while others with mobility issues won't drink as much water as they should.

The key is knowing what's normal for your own dog's water intake, so you can spot when something shifts.

Signs of dehydration in a dehydrated dog

Dehydration can creep up gradually, particularly in hot weather or after lots of exercise, so it helps to know the signs of dehydration before they become serious.

The quickest home check is skin elasticity: gently lift the loose skin between your dog's shoulder blades and let go. In a well-hydrated dog it springs straight back; if it's slow to settle, dehydration may be developing. These checks spot trouble early but don't replace professional advice — if your dog isn't getting enough water, move them somewhere cool and encourage your dog to drink. Our guide on why your dog isn't drinking water covers the common reasons, and ongoing dehydration can lead to knock-on problems like constipation.

Is your dog drinking too much water?

Just as too little is a concern, a dog drinking too much water deserves attention. A dog who's suddenly draining bowl after bowl — an excessive amount compared to their usual — may be flagging a health issue, so it's worth finding the underlying cause rather than ignoring it. As a rough guide:

✓ Normal after exercise or heat ⚠ A steady, unexplained rise ＋ Sudden, extreme thirst — see a vet

Some of the common reasons a vet might check for:

• Kidney disease and diabetes: two of the more common reasons behind a big jump in thirst, as the body works harder to manage fluids and blood sugar.
• Hormonal conditions: Cushing's disease and Addison's disease — both adrenal gland disorders — or raised calcium levels can change how much your dog drinks.
• Dental disease and medication: painful dental disease can put a dog off both eating and drinking, while some prescription medicines simply make dogs thirstier.

There's an opposite extreme, too: a dog who gulps down a huge volume very fast — often during water play — can occasionally develop water intoxication, so steady sipping beats one enormous binge. If you notice your dog is drinking a lot more than usual, or the thirst comes with other signs like tiredness or toilet accidents, and you're at all concerned, it's worth booking a vet visit to rule out an underlying cause.

How to keep your dog hydrated and healthy

Most of the time, proper hydration comes down to a few simple habits that help your dog stay healthy:

1. Keep the water bowl fresh and full

   Change the water daily and rinse the bowl so there's always clean water on offer — dogs can be as fussy about a grubby bowl as we'd be about a dirty mug. Plain tap water is perfectly fine for dogs in the UK; filtered water is fine too, but fresh water is what really matters.

2. Make water easy to find

   Put multiple bowls around the house so there's always a drink within reach, and try different bowls — some dogs prefer ceramic or stainless steel to plastic. Fussy drinkers often take to a pet water fountain.

3. Add moisture to mealtimes

   A splash of water over dry food, or the occasional switch to wet food, is an easy way to increase water intake for reluctant drinkers.

4. Cool tricks for warm days

   On hot-weather walks, carry a collapsible bowl and offer a small amount along the way, and pop a few ice cubes in the bowl at home as a treat. If your dog is ever overheated, offer cool rather than ice-cold water and get them to a vet — our hot weather guide has more.

5. Keep an eye on the bowl

   Noticing how much your pet drinks day to day is the easiest way to catch changes early. To keep tabs on your pet's water intake, fill and check the bowl at the same time each day, and use a water intake calculator for a rough daily target to compare against.

Quick questions

Sources & further reading

• Why your dog isn't drinking water — and how to help
• Why your dog is drinking a lot of water
• Dogs Trust — how much water should a dog drink