I’m watching my neighbor’s male dog for the weekend, and I took him for a pretty long walk last night - about 1/2 hour. The damn dog stopped and urinated on every tree and hydrant along our route. How much pee can a dog hold? (And this is a small dog, a miniature pinscher!)
First time dog daddy, eh? 
Male dogs mark territory with urine; he’s purposely only doing it only a half-teaspoonful at a time, so as to have enough to complete his entire route. He’s not out there to empty his bladder before bedtime, like Grandpa. He’s out there to score some babes and make sure nobody’s on his turf.
Enjoy. 