I was able to with Miles. I got him when he was 10 weeks old, and trained him to go outside. But I live in an apartment, and I was getting creeped out going outside in the middle of the night...so I decided to pad-train him a few weeks ago (he's now 22 weeks). He had already started lifting his leg (which I thought was kind of early, but whatever!)...and he still was able to be trained. I would give it a shot!
