I have an american bulldog that will put his nose to the ground and hunt, has found a few pigs, in fact last year was the best find dog i had...

I had to stop hunting him like that though, he started ranging out further and further, to when I let him go he would usually go out damn near 1,000 yards, way to dangerous for a straight catch dog to be doing that. Now when we walk into fresh sign he has his nose to the ground and trying to pull my arm off...

Daniel my hunting buddy has 2 american bulldogs that hunt and find pigs, they stay a lot closer to us, its really fun when you come up on a group that curs have found and then bulldogs are also finding em, it can turn into some work pretty quickly. RIP his male has found some huge boars too.
Micheal has a small male pit that has a good nose too, he has found some for us. He ranges out to far also though.
I like using bulldogs on smaller places with no livestock for little quick hunts, if they'll stay close to you.
Tell your buddy keep a tracking collar on him.