Meaning
As the dog was an unclean animal, the terms "dog," "dog's head," "dead dog," were used as terms of reproach or of humiliation (1Sam 24:14; 2Sam 3:8; 9:8; 16:9). Paul calls false apostles "dogs" (Phil 3:2). Those who are shut out of the kingdom of heaven are also so designated (Rev 22:15). Persecutors are called "dogs" (Ps 22:16). Hazael's words, "Thy servant which is but a dog" (2Kings 8:13), are spoken in mock humility=impossible that one so contemptible as he should attain to such power.