There are many synonyms for the phrase "great dog" that one can use. Some of the commonly used synonyms include "excellent canine," "amazing pooch," "superb hound," "fantastic mutt," "terrific four-legged friend," "wonderful canine companion," "remarkable pup," and "outstanding furry pal." These terms are used to describe a dog that is exceptional in one way or another, whether it be their loyalty, intelligence, playfulness, or any other admirable trait. Using any of these synonyms can help elevate your language and express your appreciation for your furry friend in a more creative and descriptive way.