Schipperke peeing problem

I have a 1 yr old male neutered Schipperke--Taz. He knows to go potty outside and I have no problem with him pooping in the house. However, he will pee (while walking--leaving a little "trail"). I most always never catch him in the act of doing this. He doesn't pee alot, just a nice little "trail"! He is crate trained and rarely will he pee in his crate--and never poop in it. I also have a 19 month old neutered male Sheltie--Cody, with whom I have NO problems with. Doesn't matter if I've just taken Taz out to relieve himself, I can not be watching him and will find a "pee trail". How can I keep Taz from doing his "walking pee trail"? It's driving me nuts. I just took in a pee sample to my vet to rule out any bladder issues--should have results in by Monday.

How often do you take him out every day?

He goes out first thing in morning when I get up 7:00, again in about an hour, then at least twice more before I leave for work at 11:30 am. He has plenty of times to go. He'll do his "pee trail" sometimes not long after I have just taken him out!

How long does he stay outside? You could try taking him on a short walk.

We're outside for 5-10 min. He pees good and goes till he lifts his leg and nothing comes out!!