In paragraph 2 and 3, who does the word they refer to? What does the word it refer to? How do you know ?

I'm sorry but i'm not for sure what you need on

Dogs have been considered man’s best friend for decades! most likely because of their kind and loyal nature. they make splendid companions. their loyalty is beyond compare and after all, a dog is the only thing on earth that loves you more than he loves himself! dogs see us as their friends and leaders, they’ll do anything in their power to ensure your comfort and safety.