I know it sounds bad, but I do think we all have lost our tempers at one point or another. My ferret was misbehaving once and I smacked him on the nose and walked away. Pretty much after I calmed down though I realized what I had done and felt really bad. Same as, I had been 'bad' as a child and my mother has smacked me (welcome to spanking! Ever heard of it? Seems parents forgot about it recently). Its not that they mean to hurt the reciever as much as they just lose their temper. However, if your husband felt no remorse, I would rethink having a dog. I'm not going to say rethink having a husband because well, a lot of people do not view animals as equal to humans. I don't agree with it but I know tons of people that don't like animals and yet could not ever hurt a person!
As well, I'm sure all parents have hit a point in their lives where a child does something and they feel ready to throw in the towel. I know my current boyfriend and I have gotten in fights and felt like we should not even bother to work at the relationship. But we do, we get over it. It is just emotions. This is the same, if not harder it seems, with animals. An animal cannot really understand what you want. They do not understand our language. They understand tone but they don't always understand what all the fuss is about (I remember trying to teach my ferret to roll over. He understood I wanted him to do something, he just didn't understand what this 'roll over' nonsense was all about

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I do think your husband and you should have a conversation once he has calmed down though. You need to understand each other and have a good long discussion about whether or not the dog is appropriate for your household. Maybe something else is bothering him and he just took it out on the dog. I know that sounds horrible, but maybe it is something really simple. Don't give up just yet. Communication is the key!