There are many factors that come into play in the mental and physical health of a dog, but perhaps two of the most important are diet and exercise. Diet and exercise aren’t just important for the high energy performance or working dog. They are key for the average pet dog as well.
Is there such a thing as the perfect puppy? In all likelihood there is not. There is always something one might change in any dog (or person really), but the goal should be to always strive towards raising a puppy to be its most perfect self. This is hard work, to be sure, but it is not only possible, it is necessary.
The personality of a dog is flexible and indeterminate. Dogs can be exuberant or shy; friendly or hostile; fearful or bold; aggressive or passive or some combination of the above. These differences in personality may to some extent be determined by breed, or individual genetics, but for the most part it is based on how and to what extent each particular dog has been socialized.