Psychic Moon (The Shifter Chronicles 1)

Animal Control Officer Derek Williams is a wolf shifter and not one inclined to long-lasting relationships. Not only does he take animal abuse personally, he has a temper and isn't afraid to show it. However, he changes his tune when the newest veterinarian starts working for the Animal Services Center.
Recovering from an abusive relationship and hiding supernatural abilities of his own, Brian O'Donogue wants a fresh start and a new place to call home. Quickly dubbed the "animal shrink" by co-workers, Brian doesn't know what to make of Derek at first. Then he manages to confront Derek during one of his rages, and they both see each other in a new light.
Eventually they take a chance on their feelings and the ensuing relationship is better than either of them could have hoped—until a rogue wolf shifter attacks Brian. The abrupt attack forces Derek and Brian to confront their secrets and whether their relationship can weather the storm heading their way.
The rogue shifter is out there, and he's hunting them.
BONUS STORY: Celtic Warrior and Wolf Spirit
Derek and Brian are celebrating their first Christmas together, and Brian is determined to show Derek a Christmas like those he shared with his family back east. A wolf shifter, Derek has never celebrated a traditional Christmas before—his pack would usually shift on Yule and hunt down prey. But the unexpected appearance of Brian's abusive ex-boyfriend on Christmas Eve threatens not only Brian's holiday plans but his future with Derek.
Can be read as a standalone
Second Editions with updated and revised text.