Dreaming of blood is a good thing. Dreaming of a dog fighting, being fierce or barking shows that it is not harmonious with friends or that friends are not worth relying on. If I bite you or attack you, be careful that the people you trust cheat you and hurt you, but the compatibility of the two can resolve the bad omen.
Friendly reminder: oppose superstition and advocate science, be a normal person and answer you scientifically. Maybe you are under too much pressure, or for other reasons. It doesn't matter. Don't believe those boring things!