Like human beings animals can smile and laugh  

Yes when we express our feelings we used to laugh but i also think that animals also used to laugh when they express their feeling.

I have quite often tried to capture the feeling of elation and joy on the countenance of my pet dog.In the same line I had also situations in which the dog was in a pensive mood. Though it is hard to assign valid reasons for these mood shifts in pet animals, it remains a fact that they do have personal feelings of their own.

Yes according to me that all animals can smile and laugh like human beings. But the only different is that they have their own way of doing it. It may happen they use different tones which stands for laughing and smiling. For example if a dog cries we can know that it is crying. But are the crying of dog is similar to us? No. So it is sure that the animals have different ways of expressing joy and sadness.

They can smile and they can cry. I have seen my cats do both. My three elder cats were very sad when my brother died, and they knew it and felt it.

When my one cat, Frisky's little sister, Sparkle was attacked by a skunk, she cried like there was no tomorrow. She had to be cleaned off quickly and then after she was cleaned off she had to be held and comforted for along while. She was so scared after that.

Cats most certainly have emotions.