Should animals have rights and why?

While animals lives with people in people's world, they must have rights like people. In the wild nature they already have an own rules (see Discovery, Explorer Viasat, National Geographic, BBC etc.). Animals must be to protected by the law. In Ukraine one maniac get 2 years prison for killing the dogs. But every day I found dead cats near the road and nobody carrying about it. How animals can complain on a people?