A general rule of thumb is that a puppy can only "hold it" for about an hour for every month old after 3 months of age (a 4 month old puppy can hold for about an hour, 5 months 2 hours etc.)
Out of curiosity, please tell me that you are leaving food and water available for him the whole time you are gone. 12 hours for a 12 week old puppy is far too long to go without food and is a hypoglycemic crisis waiting to happen.
__________________  Don't get your knickers in a knot. Nothing is solved and it just makes you walk funny. |