How much does a dog drink? As a general rule, dogs drink 20 to 40 ml of water per pound of body weight per day. This comes out to about 3 to 4 cups of water for a 20-pound dog. Some dogs may drink less if they are eating canned food as canned foods contain a high percentage of water compared to dry food.
Anything more than 20 to 40 ml per pound per day is considered excessive and can be associated with diseases such as diabetes mellitus or kidney disease.
For more information on Excessive Drinking, please read Polyuria and Polydypsia in Dogs