PawsMathThe basic rule: about 1 ounce per pound
Healthy adult dogs need roughly 50–65 mL of water per kg of body weight per day, close to 1 fluid ounce per pound. Part of that comes from food. Kibble is only about 10% moisture, so a dry-fed dog gets nearly all its water from the bowl, while a dog on canned food (75–80% moisture) may drink half as much.
Daily water needs by weight
| Weight | Water per day | Cups | Excessive above |
|---|---|---|---|
| 5 lb | 5 oz (140 mL) | 0.6 | 8 oz |
| 10 lb | 9 oz (270 mL) | 1.2 | 15 oz |
| 20 lb | 18 oz (540 mL) | 2.3 | 31 oz |
| 30 lb | 28 oz (820 mL) | 3.5 | 46 oz |
| 50 lb | 46 oz (1360 mL) | 5.8 | 77 oz |
| 70 lb | 64 oz (1910 mL) | 8.1 | 107 oz |
| 90 lb | 83 oz (2450 mL) | 10.4 | 138 oz |
When to worry about water intake
Drinking much more than usual (over 100 mL/kg/day), especially with more frequent peeing or accidents in the house, is one of the earliest signs of diabetes, kidney disease, Cushing’s disease, liver disease, pyometra in unspayed females and some urinary infections. Measure what your dog drinks over 24 hours (fill a jug, top up the bowl from it and note what is left) and share the number with your vet.
Drinking much less than usual for more than a day, particularly with vomiting, diarrhea or lethargy, can lead to dehydration and also needs a vet check.
Tips to keep your dog hydrated
- Keep fresh, clean water available at all times and wash the bowl daily.
- Take water and a collapsible bowl on walks over 30 minutes and on car trips.
- Add water or low-sodium broth to kibble, or feed some wet food.
- Provide shade and extra water in hot weather; avoid exercise in the hottest part of the day.
More questions
How much water should a dog drink per day?
A healthy dog drinks roughly 1 fluid ounce per pound of body weight per day (about 50–65 mL per kg). A 40 lb dog needs roughly 35–40 oz, or 4.5–5 cups. Hot weather, exercise, nursing and a dry-food diet all increase this.
How much water is too much for a dog?
Vets generally consider more than 100 mL per kg per day (about 1.5 oz per lb) to be excessive thirst, called polydipsia. It can be a sign of diabetes, kidney disease, Cushing’s disease, infection or medication side effects and should be checked.
Do puppies need more water?
Yes. Puppies need more water per pound than adults and dehydrate quickly. Offer fresh water at all times and roughly half a cup every two hours while awake for young puppies, adjusting to your vet’s house-training advice.
My dog eats wet food and drinks very little. Is that normal?
Yes. Canned food is about 75–80% water, so dogs on wet food often drink much less from the bowl while still getting enough fluid overall.
How can I tell if my dog is dehydrated?
Look for dry, sticky gums, sunken eyes, lethargy and loss of skin elasticity. Gently lift the skin between the shoulders; it should snap back immediately. Dehydration with vomiting or diarrhea needs a vet.
Sources
- Nutritional Requirements of Small Animals, Merck Veterinary Manual
These numbers are estimates for a typical healthy dog. Your vet knows your animal and should have the final say, especially if there's a medical condition involved. Disclaimer