There's no question that your dog needs to have access to clean water all day long. If he gets thirsty, he needs water to be there for him in his bowl.
How often you should change the water in your dog's bowl
Getting the right kind of bowls for your dog
How often should you clean your dog's food and water bowls?
Even though you may have stainless steel bowls, you still have to keep them clean in order to ward off that harmful bacteria and ensure that dirt and grime doesn't build up. You should wash your dog's food bowl with hot, soapy water after every meal, or you can put it in the dishwasher to clean it as well. Washing it in the sink separately from your dishes is the better option not only for health reasons, but because you'll save big on your water bill too.
If you ever notice that your dog's bowl has a scratch or crack in it, get rid of it and buy a new one.
Giving your dog enough water
While having the right kind of dog bowls and keeping them clean is important, you also need to make sure you're giving your dog enough clean water every day, too. According to the American Kennel Club, dogs require about 1 ounce of water per pound of body weight per day, while puppies that have been weaned need between one half ounce and 1 ounce of water per pound of body weight per day. If your dog is active, he's going to need even more water.
If you notice that your dog is drinking way more than usual and it's not because he's just exercised or eaten, then a medical issue could be at play. Kidney disease, dehydration, parasites, liver disease, vomiting, fever, and infection can all cause your dog to become much thirstier than usual. It's always best to call your vet about your dog's increased thirst instead of trying to diagnose the issue yourself.
Conclusion
You should change your dog's water at least twice per day. At the same time, you need to use the right kind of dog bowl and keep it clean, as well as give your dog enough water and monitor his drinking habits.