Just get the perk that gives you infinite Dogmeat(s).
I'm really not missing him that much.
I just completed The Replicated Man. So weird how different experiences can be, the first two times I played that I first heard about him when I got to Rivet City, I spent like 10 hours hunting around all over the wastes for information and tapes and what have you.
This time, because my intelligence is much higher, I heard about him in Megaton, some random "Underground Railroad" type person approached me in the wastes and gave me a part, and then I turn the quest in to guy looking for him at Rivet City and that's it.
Also, I ran across something... weird in the wasteland. It was at a barn near Vault 106, late at night, as I crept up to the entrance, I noticed some raiders inside acting odd.
The four of them seemed to be having a conversation, but one of them wasn't wearing clothes (other than underwear) and he had his hands up in the air. Another was wearing what seemed to be a white BDSM outfit that barely covered his privates. Naturally I shot him first, but I really want to know what the hell was going on. At first I assumed the guy with his hands up was a captive, but it turned out he was just a nearly naked raider... I'm so confused.