Black Dog by Victoria Danann

The Hawking family is at home at the Northern Ireland farm and wolf-dog kennel for Yuletide when Blackie goes missing. Instead of a joyous celebration of family and friends, Ram’s mate and elflings are beside themselves with fear and worry. As Song and Litha join the search, the story takes a turn into the dark world of dog fighting and the kidnapping of adult male dogs that match promoter criteria.
Black Swan rarely gets involved in the mundane affairs of the world because that’s simply not their purpose, mission, or directive. But when Simon’s office is drowned in messages from retired knights insisting that Blackie is unofficially one of them and that an exception must be made, he relents and orders available personnel to assist B Team with a rundown.