Dead Heat by Patricia Briggs (2015) Ace

The Werewolf family, Charles, the son of the Marrok (over all Werewolves in the U.S. maybe world-wide) takes his mate and wife, Anna, to an old friend’s horse ranch to pick a new horse.  While there, they investigate the disappearance of a little girl who went to school with his friend’s granddaughter.  It turns out that she was replaced by a fey’s fetch changling.  The friend is old and dying and refuses to be turned by his son (the local alpha).  But there is something left for him to do.

The story is the best so far in the series.