In Valiant Comics' continuity (VH-1), "Bloodhound" made his first and only appearance in Magnus Robot Fighter #20 as a Freewill "sniffer-rob" on Mars at the end of the 40th Century.
In Valiant Entertainment's continuity (VEI), the hound was first seen in Book of Death #1, unnamed and depicted as a some sort of Cocker Spaniel. The hound was then re-introduced as a White Shepherd type and a companion of Ray Garrison aka Bloodshot beginning in Bloodshot Reborn #5, although he had first been a member of the Bloodshot Squad as seen during the Bloodshot Island arc. Bloodhound is now the family dog of Ray Garrison, his girlfriend Magic, and their daughter Jessie.
Like his human namesakes, Bloodhound is a Nanite-enhanced being, however, it remains to be seen what the hound is fully capable of, besides being very clever and having heightened senses and stamina.