Dogs — very friendly and smart animals. Many dogs can live 1-5 years, and others can 1-10years.

Dogs very popular animals on the world. There are police dogs, very big, and dogs for fishing. In the world there are 500 million dogs, but 75% — not have house.

Many dogs have all viruses and can infect this. The ancestors of dogs originated from the wolf breed. The dog is the first of the wild animals, which was domesticated by man in the Stone Age — about 12 thousand. years ago.