Mongrel by Lee Colgin

Mongrel, a creature more wolf than man, leads a lonely life on the fringes of pack society—until the night a handsome vampire shows up with a mysterious request.
Bowie, a vampire cursed to a life of endless nights, maintains close ties with his human family. When young girls in their village go missing, he must act quickly. But to find them, he’ll need to convince the local werewolf pack to loan him their best tracker—a wolf known as the Mongrel.
Though he hates the slur, Andras is used to being called Mongrel. When Bowie refuses to refer to him by anything but his given name, Andras can’t help a flicker of unexpected trust toward the stranger. He volunteers to help Bowie, risking banishment.
Can two tenderhearted men overcome their traumatic pasts and work together to rescue the girls before it’s too late? Or will the world’s most prolific killer snuff the flames of their passion along with the lives of the captives?