How Much Water Should a Dog Drink Per Day?
Water intake is one of the few things you can measure at home that gives real diagnostic signal. A sudden change in drinking is often the first sign of a problem — which is why knowing your dog's normal matters more than knowing the textbook range.
The baseline formula
Roughly 50–60 ml per kilogram of body weight per day, including water in food. A 20 kg dog: about 1 to 1.2 litres. A 5 kg dog: 250–300 ml. Wet food supplies a meaningful fraction of that, so dry-fed dogs drink noticeably more.
What legitimately changes it
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The number that means 'call the vet'
Persistently above about 100 ml per kg per day — roughly double normal — with no hot-weather or exercise explanation. That threshold is the classic trigger for investigating diabetes, kidney disease, and Cushing's.
How to actually measure it
Fill a measuring jug each morning, use only that water for the bowl, and measure what's left at the same time next day. Bowl-based guessing is useless. Do it for three days to get a real baseline.
The mistakes that cost people money
- Guessing intake from how often the bowl is filled.
- Ignoring increased drinking because the dog seems fine otherwise.
- Restricting water to reduce urination — dangerous.
- Comparing your dog's intake to another dog's rather than to its own baseline.
Common questions
Is drinking a lot at night normal?
A single large drink isn't concerning. Sustained increased night drinking often is, and is worth measuring.
Can a dog drink too much?
Yes — excessive intake can dilute sodium. Water should be available, but a sudden huge increase needs investigation.