Hello,
There are medical conditions that cause puppies to drink too much water. Conditions like kidney disease, or liver malfunction or even poor diets, or diabetes. So, if you think that your puppy is drinking too much water please discuss it with your veterinarian. It is important to say that fresh water should always be left out and available for your pets. In most cases they’re drinking what they need to and withholding or rationing water can adversely affect them.

Hello,
Without knowing more about the health status of your dog and the size and type of chocolate eaten I cannot answer this completely. The pet poison helpline can calculate the answer based on a series of answers to questions they will ask. This is the best place to find the answer to this question.
In general a healthy normal pup with a small milk chococolate is unlikely to cause an issue.
There are also several “choc tox” apps available for free online. They may help provide some guidance.