My name is Dewie!

Dewie is a 6-year-old purebred male pug that I purchased from a breeder. He is sweet, snuggly, playful, silly little pug. He's generally pretty quiet, but howls at emergency vehicles. Dewie is such a cutie. The issue that I'm having is, Dewie is frequently exhibits territory marking. It seems to be triggered by anxiety and/or the presence of my senior male dog. Despite my best efforts to remedy the problem, every thing I've tried has been unsuccessful. Dewie is wonderful dog and deserves people that are patient and equipped to handle his needs.