The practice of dishonoring foes by denying burial made dogs, among other animals (1 Sam 17:44; Jer 8:2; 16:4), the de facto undertakers who “licked the blood” of many (Naboth, 1 Kings 21:19; Ahab, 1 Kings 21:24; 22:38; Jeroboam, 1 Kings 14:11; Baasha, 1 Kings 16:4). To fulfill the prophecy, Jezebel’s body does become dung on the face of the field, but only after the dogs have digested it (2 Kings 9:10, 36). The dogs may lick Lazarus’ wounds as a foreshadowing of his death and interment in them (Lk 16:21).
The dog’s regurgitation reflex, useful for transporting food to their pups in their former wild state, served to cement their label as unclean (Prov 26:11). The logical connection between a dog’s diet of refuse and its unclean habits further supported the belief that what enters in through the mouth does defile one.
The struggle for survival at the town dump and a semi-wild existence did not produce friendly dogs. Dogs seemed to know nothing of obedience and were dangerous to pet (Prov 26:17). The fear of being eaten by such dogs is real (Ps 22:16-17).
In return for a begrudging toleration they provided watchmen services, and they were even believed to sense spiritual dangers. The absence of a dog bark during Israel’s exodus indicates that God miraculously silenced either the departure of the Israelites or the dogs so that they did not alert the Egyptians (Ex 11:7).
The prophet likens his defenseless nation to a pack of lazy watchdogs that could not bark anyway (Is 56:10).
ed. Leland Ryken, James C. Wilhoit, Tremper Longman III, Dictionary of Biblical Imagery, Inter-Varsity Press, Downers Grove, Illinios, 1998, pg 29