All dogs have days when they drink a bit more than usual, and this is often nothing to worry about. However, a noticeable and persistent increase in thirst can sometimes be an early sign of illness—especially in older dogs. If you’re concerned that your dog is drinking more than normal, it’s always best to speak with a vet for advice and guidance.

Dogs drink more because they’re thirsty. There are many reasons why your dog might be more thirsty than normal. Sometimes it’s because of an illness that needs prompt investigation and treatment. Especially if drinking more is accompanied by other changes, such as weight loss. Drinking more also means your dog will pee more. A simple urine test can often help you and your vet find out the reason why your dog is drinking more. 

What to do if your dog is drinking more?

Dogs normally drink about 50ml per kg of body weight in 24 hours. So a 10kg French Bulldog should drink around 500ml per day, and a 30kg Labrador will drink 1.5 litres. 

If your dog is drinking more, we need to rule out the innocent reasons. Then find out how much they are drinking and if anything else has changed.

• Check that your dog's bowl gets filled regularly, so they’re not gulping water because they’ve been waiting for it.

• Feel your dog's body, ears and paws. Could they be hot or have a fever?

• Find out how much they are actually drinking. Measure water into their water bowl and keep it topped up. Record how much you add and how much is left after 24 hours. Try to prevent them from drinking out of puddles or streams while you’re doing this.

• Check how much your dog drinks over several days to see if there’s a pattern, like after eating, after walks, or early morning.

• Collect a urine sample in a clean jar or specimen bottle from the vet. If your dog drinks more, their urine is more dilute. The vet can check this and look for other clues to the underlying cause.
  
  

The common causes of drinking more

The most likely reasons for empty water bowls will be ‘physiological’. This is vet-talk for drinking more because your dog’s hot or out of breath, or because they’ve eaten.

• Dogs lose water when they pant to cool down or because they've been running hard or playing madly.  

• Moving from a wet to dry food means your dog gets less water from their dinner and needs more from their water bowl.

Drinking more as a symptom of illness:

• Vomiting and diarrhoea: dehydration

• Eating something harmful: grapes, chocolate, anti-freeze

• Diabetes (sugar diabetes)

• Cushing's disease

• Chronic kidney disease

• Pyometra (unneutered female dogs)

• Heart disease

• Urinary tract infections

• Liver disease
  

When to worry

Call your emergency vet if your dog is drinking more and:

• May have eaten something harmful

• Has very severe vomiting and diarrhoea, especially with blood

• Seems vacant or confused

• Has a severe and worsening cough

• Having breathing difficulties

• Weak or collapsed

• Having seizures

Speak to a vet as soon as possible if your dog is drinking more and:

• Losing weight

• Peeing more often, and the pee (urine) looks or smells abnormal

• Is an unneutered female who’s been in season recently

• Has mild vomiting and/or diarrhoea

Can (and should) I prevent my dog from drinking more?

Don't restrict water when your dog needs it. This can be distressing and harmful for them.

Dogs need to drink more to make up for fluid they may be losing in pee, vomit, diarrhoea or panting. Preventing them from drinking will worsen dehydration and make them even sicker.

Preventing the underlying cause:

Panting:

• Keep rooms cool and comfortable for your dog

• Avoid going for walks in very hot weather

• Clip and/or thin your dog’s coat to keep them cool 

Illness:

• Visit your vet to diagnose and treat the underlying cause

• Keep all harmful substances out of sight, smell and reach of dogs

• Managing long-term illnesses can help reduce excessive drinking, even when the condition can’t be cured. These include Cushing’s disease, chronic kidney disease, and liver disease. But be aware—drinking more can also be an early sign that the condition is getting worse.
  

Things to look out for if your dog is drinking more

Warning signs that suggest there's something wrong when your dog’s drinking more include:

• Changes in eating habits

• Weight loss or a change in body shape

• Changes in smell or colour of urine

• Vomiting and changes in stool

• New cough or breathing faster at rest or asleep

• Having less energy

How to help at home if your dog is drinking more

If your dog has a diagnosed condition such as Cushing’s disease, kidney disease, diabetes, liver disease or heart disease, they may naturally drink more than other dogs. You can’t stop the extra thirst, but you can help them stay comfortable and healthy at home:

• Keep fresh water available in several places. This is especially helpful for older dogs or those with mobility issues.

• Never restrict their water. Limiting water can make them very unwell, especially with kidney disease.

• Dogs with chronic conditions often need to pee more. Let them out more often to prevent accidents and keep them comfortable.

• Give medications exactly as prescribed and keep up with any special diets. Good management of the condition often helps reduce excessive thirst.

• Monitor changes in drinking or peeing. A sudden increase can be an early sign that the condition is changing or worsening. Watch out for any new symptoms too. Keep notes to share with your vet. 

Routine vet checks for blood tests or urine checks help catch problems early and adjust treatment when needed.

What's the vet treatment for dogs drinking more?

Vet treatment is only necessary when there’s an underlying illness. Treatment will depend on the underlying illness. Some conditions may need lifelong medication and monitoring.

Are some dogs more likely to drink more than others?

Some dogs are more likely to pant because they get hot more easily:

• Dogs with long coats or thick undercoats, including Golden Retrievers, Newfoundlands, St Bernards, and Huskies.

• Short-faced dogs (brachycephalic breeds), including Pugs, French Bulldogs, and Boxers.
  

Difference in risk of other diseases:

• Older dogs: higher risk of liver disease and chronic kidney disease

• Dogs that scavenge are more likely to eat something harmful

Other reasons dogs may drink more

There are some less common causes of drinking more, including:

• Psychogenic polydipsia: Increased drinking that starts as a habit or behavioural problem. Eventually, it also causes medical problems.

• Saltwater poisoning: From drinking too much seawater at the beach.

• Diabetes Insipidus: Also known as ‘water’ diabetes. A rare brain illness that means your dog can’t produce concentrated urine.