It's a fairly big dog - medium large and completely white with 4 brown patches (two over its eyes, one on its back, and one on its tail). It's a male - neutered. We think he's an American Pitbull Terrier, but we're not sure. He's super friendly and well-trained and VERY cute, so I couldn't imagine someone just leaving him to fend for himself. He didn't have a collar or tags, and no chip. If you know ANYTHING about this dog or someone who might be missing him, let me know or call the Naperville Police Department's Animal Control Unit. :) If you would be interested in adopting him after 7 days... call them and let them know as well so that he won't be put to sleep.