What does the dog symbolize?
Trust and faith. mostly trust
In Western culture, snakes generally symbolize something dangerous, dishonest and repulsive. Dogs symbolize the opposite: trustworthy, loving, devoted protectors. So this dream suggests something dangerous and nasty attacking something trustworthy and protective. ... The dog might symbolize the dreamer's sense of what is right as well as the instinct for self protection. The snake might be a temptation that threatens to overwhelm the dreamer's common sense.