Hi, I have a shih tzu/Japanese chin mix and he's about 5 1/2 months now and he gets tired of one type of food pretty quickly. I mix his dry food with a bit of wet food to make it more enticing. Unfortunately, where I live doesn't have a vast variety of dog food, and 'puppy' food is even harder to find. So anyway, I won't have as much of a difficult time if I could finally feed him adult food. I would have a few more choices at least to switch it up. Anyway, how old do you think he should be before giving him adult dog food? Many thanks for your response.