You have to do something to cause extraordinary pain to that dog to cause it to want to bite you if it is a dog that you are on good terms with and familiar with. You cannot just provoke a dog to anger by doing nothing. Therefore if you have a dream in which you are bitten by a dog that you know and love then you will have had to do something pretty awful to anger it. The dog represents someone that you know in real life and the bite represents their anger towards you. What was it that you did to anger this person? Is it something you can apologize for? If not then how do you plan to reconcile your relationship and keep the floodgates open for more friendliness. You need to be able to work through this if it is something that is truly bothering you and if you have done something to tremendously hurt someone. Either that or you will have to risk abandoning the relationship for some stupid mistake you made. Don't let this mistake be the undoing of a great relationship. Be more apologetic and let them tell you how they feel. You need this honesty if you hope to salvage your friendship still.
If you have a dream in which you are bitten by a dog but the dog is one that you are not familiar with then this could be a dream to be careful where you tread. You could be getting into territory that few people are allowed in and it could make things uncomfortable for yourself and anyone else that you might know. Make sure that whatever you do, you don't cause any more damage than has already been done in this broken place. Don't encroach on anything that you do not understand or you are going to end up hurting yourself and anyone else that is involved in this intertwining tale. This is what you have to do in order to make sure that you come out on top. It is the only thing you can do.