This might be crazy but looking for a pit/boxer mix

I lost my dog not too long ago even posted here on this board and in the paper looking for him, no luck. After that loss my roommates moved out and left me with a small boxer/pit bull mix. When he was 5 months old he became very sick I had him at the vets for over a week, he had surgery they did what they could but in the end he didn't make it. I know he has a brother out there, and I'd like to find him. When my roommate bought him it was at Petsmart and he was a groomer, he paid 50$ for him this would've been around the end of the March. Like I said I hope to find his brother. If anyone can help me out or has any information that would be great thanks. He was a brindle color with a white underside and legs (the bottom of his paws were pink) and a white stripe down the middle of his face. I'm sure his brother would look the same. skampdmb@gmail.com