Can pets read human emotions?

I definitely think that pets can read human emotion and even human illness. The reason behind my answer is that I have two dogs and any time I am upset or not feeling well, my small dog will want to lay in my lap or he will stay very close to me until I am feeling better. But he is my daughter's dog and he is very loyal to her, so he normally chooses to be close to her. Same goes for my big dog, but generally she spends her time with all who live in our home.