"Douche-Bag Dog Owner" - those that believe holding onto a leash while driving and allowing your dog to run beside your moving vehicle is not cruel, dangerous and inhumane. Synonyms include: Lazy Ass Dog Owner, Careless Fat F*ck.
"Did you see that DBDO? His dog was running beside his truck when the leash got tangled and the dog was subsequently run over and killed. The owner is still driving and hasn't noticed yet.