You wouldn't think that would be a competitive field, but, you know, comics. There you have it.
|Robbie is judgmental.|
Robotman's armored shell possessed a fully functioning human brain, which explains why he kept his personality and ability for speech. Where exactly Robbie the Robotdog picked up his articulate sense of wry humor is anyone's guess. I doubt it was a dog's brain bouncing around that metal crockpot of a skull, because not only would that not give him the power of speech it would also be super-super sad.
Like his owner, Robbie could pass for "normal" by slipping into a lifelike rubber suit made just to his specifications. For Robotman, that was latex gloves and mask which allowed him to pass as Paul Dennis, for Robotdog it was a fursuit. Like most of your discerning adult convention aficionados possess.
Robbie wasn't particularly any great help to Robotman's crimefighting career - he made a better hostage than helper and primarily stuck around for the comic relief. Still, Robbie's absence probably played a bit of a key in James Robinson's and Paul Smith's Golden Age miniseries - a prestige format book which starred dozens of lesser-known golden age superheroes now under DC's banner, and in which Robotman was an emotionless machine of destruction allied with the Nazi cause.
It's hard to imagine Robotman signing up with a second effort at the Third Reich with a wise-cracking metal mutt dropping bolts on his new carpet. I can't say what happened to Robbie, but he was obviously missed.