Dogs need plenty of water, just as people do. However, some dogs drink more than they should and it results in frequent urination, with those types of dogs, their water intake will have to be monitored along with activity. I am not saying deprive a dog of water completely. Water is very essential to a dogs well being. For dogs that have self control you can leave water down for them all day. Every day the water should be changed, the bowl should be cleaned to eliminate any bacteria.

Every dog is different in the amount of water they do drink. Some tend to drink les when they should be drinking more, in this case you can add a small piece of bullion flavoring cube for flavor. I have seen one dog that will drink nothing but natural spring water. Some dogs drink too much water and this tends to lead to accidents if the dog is not able to go out when necessary. When you are home and have more time to let the dog out or take it for a walk, more water can be given. Older dogs tend to regulate their water, they tend to adapt to your routine quite well.

Dogs can become easily dehydrated.
How to determine dehydration: A dog may be dehydrated even when drinking plenty of water due to medical problems, over-activity, heat or stress. One way to easily determine this condition is to check for skin elasticity. On the upper back just below the shoulders, using your thumb and forefinger, pinch the skin gently, lift up and then let go. If the skin returns to normal quickly, your pet is absorbing enough water. If not, encourage your dog to drink more water and call the vet immediately.

Puppies are easily over-watered.
This can be a serious problem when trying to housebreak. What goes in, must come out! Therefore, puppies should be on a strict feed-water-walk schedule as soon as possible in order to successfully accomplish housebreaking and to establish normal eating and drinking habits. You should not let a housebreaking puppy have unlimited access to water. After the puppy is done eating or drink, the puppy should be taken outside immediately. Be patient. If the puppy does not eliminate its waste after several minutes, take the puppy back inside and put it in a cages area and try again after 5-10 minutes.