Everybody names their dog Chief. Think of this as a good creative thinking exercise for your kids.
Be sure that they know what the dog is (breed, size, fur color, etc.) Do you know the dog's personality a bit? Does he have any significant traits that you want highlighted in the name?
Story: When my sister and I were very young (I was 4 and she was 5) we adopted a kitten to replace the one who had died. My sister was extremely attached to the old cat more than anybody else, so she was basically spearheading the entire thing under supervision of my parents. We always had good luck with Persians, so we finally found an all black male kitten Persian. It came time to bring him home, and we were discussing names. Know what she picked?
This was a situation where my parents had to override her judgment. And if they wouldn't, I would. That name was unacceptable and stupid and we all knew it except for her.
Thankfully, after a long talk, we picked out another name. George. Acceptable. Worked out fairly well.