Thanks Lizbud,
It is not only a question of belief but a question of nature and of ethics. Is there any point in responding to a cow the same way you would respond to a hamster?
Would you expect a two year old human to react to you as a two year old horse?
Can you think of a twenty year old crocodile or cat thinking the same way as an adult human? Or even the same as each other?
It is ridiculous.

Can a dog then think of human emotions? No, but can certainly perceive them.
Does a dog have emotions? Yes.
Are human emotions the same as dog emotions? No, they are not. The dogs emotions are no less important, in my view, but not the same. Dogs have different values, social structure and emotional values. That does not make them less valid - just different.
Can a dog feel guilt? - No.