Nightbitch by Rachel YoderCall Number: Fic Yoder, Rachel
An ambitious mother puts her art career on hold to be a stay-at-home mom, but the experience does not match her imagination. Two years later, she discovers a dense patch of hair on the back of her neck. In the mirror, her canines suddenly look sharper than she remembers. Her husband casually dismisses her fears from faraway hotel rooms. As the mother's symptoms intensify, and her temptation to give in to her new dog impulses peak, she struggles to keep her alter-canine-identity secret.
(Description from Amazon)