It means you have lost trust in someone.
Reveals an overprotective, suffocating relationship.
The are issues with friendships or relationships.
The dog in the dream world symbolizes loyalty and friendship. If the snake attacks your dog, it shows that you have lost trust on an individual very close to you. Maybe a friendship is at risk, or you may be having current personal issues with a friend or your significant other.
Dreaming of a snake attacking your pet means issues with a relationship
This dream may be disclosing that you have realized you are in middle of an overprotective or demanding relationship. Perhaps, you are the one who is suffocating or straining a close relationship -or a friendship; as a result, your social relations are being impacted negatively.
Now, in this line of interpretation, this dream may reveal that your personal failures or poor decisions are undermining the way you get close to your friends or family members. Precisely, the snake in this kind of dreams is not the representation of demons or evil spirits as has been believed since ancient times; instead, this reptile is a dream symbol embodying a few perturbing elements or impulses in you that are damaging your relationship with your loved ones.
A snake attacking or biting your pet may be telling you that an external negative element (represented by the snake) is affecting your relationship with your best friend, or even worse, your relationship with your partner, boyfriend or spouse.
Dreaming of a snake biting your pet shows you are being needy
One of the characteristics of our pets, especially the dog, is their desire to be loved and pamper by their owner. Having said that, a dream in which a snake bites your pet, is subtly indicating that your eagerness to be accepted or loved by others can set you up for serious problems. In this case your dreaming mind would be warning that constantly seeking the approval of others may carry a very high emotional cost for you.
Finally, consider the possibility that the snake is just disclosing something negative about the dreamer, in this case the dream may be suggesting that you, dear reader, are the cause of conflicts or disputes that have been happening to you lately. I strongly recommend to look at yourself in order to find some attitudes, habits or reactions that may be bringing conflicts or disagreements with your loved ones.