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.
Dogs can suffer from a whole host of diseases and other serious health problems. Some of these conditions are inherited, while others are caused by viruses; still others are related to lifestyle and environmental influences.
You may have felt that choosing a breed was the biggest decision you had to make before getting a dog. But now that you have made that choice, you are now faced with a more basic decision: do you want a male dog, or a female?