What the Bible says about Dog(s) as Derogatory Term for Gentile
(From Forerunner Commentary)

Psalm 22:16 "Dogs" was a common term used by first-century Jews in reference to Gentiles. The Messiah was surrounded, there at the foot of the stake, by Roman soldiers. Richard T. Ritenbaugh Christ's Death, Resurrection, and Ascension Related Topics: Dogs | Gentiles | Jesus Christ's Crucifixion | Roman Executions