A pet is made or kept by humans as companions. In recent years, more and more people, young or old, rich or poor, to keep a pet like a dog, cat, monkey and so on. Pets are loved by the people. Not only is it good for the heads of friends and family members. Although there are people, their behavior is sometimes better than humans because they remain faithful and obedient to the master. There are many stories he told us that an animal that saved his life, or master of still travel thousands of miles to return home. This makes it even more beautiful. In addition, trained animals are very useful. For example, a dog trained to assist blind and walking trained pigs can even get drugs imported goods. However, pets are problematic. Some pets such as dogs or snakes, people can attack unexpectedly. Many people get sick or because the virus to leave pets HY. And some animals are dirty and toxic. Therefore, do not need an animal breeding.