Do animals smile in the same way humans do?

 Otra pregunta en Quora. No me culpeis, tengo como 300 relativas a los animales, y algunas son muy buenas, así que las reciclo aquí.
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People smile, so human beings are animals that smile, so some animals smile. If you had added the topic Evolutionary Biology to your qestion I would have simply written people smile, so some animals smile.
Bonobos smile: Bonobo smiles - Lola Ya Bonobo.

This can be a little controversial for someone that has learned that great apes make fear grins similar to smiles when they area scared, but in the case of bonobos they can do both things "fear grins" and big open smiles.
Chimpanzes smile, or make playfaces:

That are quite different to fear grins or grimaces, or so, here is one of the second (look at the chimp on the left opening the mouth and showing her teeth)

About cats and dogs, I have cats, they show their social open mind and good humour in many ways, but never showing a smile, al least in my experience.
I have not fear to throw myself in the outerskirts of the so called antropomorphic fallacy, in my experience the greater fallacy is to permit your prejudices prevent you listening to what a well observer can tell you, and seeing what you can see with your own eyes.  So, as they saying goes in Spanish: soy todo orejas -I am open to listen- if anybody has a testimony about a dog or a cat wearing a expression similar to a smile to show good humour.