Dogs in general will often represent faithfulness and loyalty. They are know as "man's best friend". From a Biblical perspective they can speak of ungrateful people (Matthew 7:6) or wicked individuals and adversaries (Psalm 22:16). They can be protective or vicious in nature and have a wide range of personalities that should be taken into consideration when considering this symbol's meaning.
* Symbol meanings provided by www.mydreamstories.com should not be used as a dream dictionary. They are for reference only and both dreamer and interpreter should be careful to listen to the voice of Holy Spirit as to what any particular symbol means in any specific dream.