One antonym for the term "dog-tired" would be "refreshed." After a good night's sleep or a relaxing day, one can feel completely refreshed and energized. Another antonym could be "awake" or "alert," indicating that one is fully conscious and responsive. A person who is not "dog-tired" would also be considered "energetic" or "zealous," indicating that they possess a surplus of energy and enthusiasm. They could also be described as "invigorated" or "reanimated," indicating that they have been rejuvenated after a period of exhaustion or inactivity. Overall, the opposite of "dog-tired" would describe someone who is active, awake, and full of vitality.