This is a detail of an Art Deco piece. Often Deco artists would feature greyhounds and I think it was something to do with the speed of modernisation at the time. The famous Greyhound bus line, with its distinctive deco logo, started around the nineteen twenties. Dogs are particularly renowned symbols, obviously because of their close association with humans. Yet hounds are often terrifying creatures in mythology. Hecate who haunted crossroads had a whole pack of hell hounds at her service. Cerberus, was usually depicted as having three heads. Under orders from the King , Cerberus was brought from Hades by Heracles, but the king found Cerberus so scary that Heracles had to take him back. But the point about greyhounds is that they are sleek and fast. In Irish mythology the hound is revered and of course, Cuchulainn means Hound of Culaan. All Celts whether mainland or on the islands revere the hound and there is no evil associated with them. It is thought that in all likelihood the ghostly hound of folk tales was introduced by Christians. And let's not forget Dante's "veltri". There is much debate about this but it is clear that the beasts were strong and fast. In The Wood of the Suicides Dante saw two sinners pursued by "black bitches, eager and swift as veltri loosed from their leash." Nere cagne, bramose e corrente, Come veltri ch'uscisser di catena". In Dante's world, sinners needed to beware!
Addendum: I am reminded by my photographer friend, Mick, of the Robert Johnson song, regarding events at a crossroads and "Hell Hound on my Trail". The old myths are the best myths. I must certainly dig that one out from my collection and give it a spin!