Mandy Lamb and the Full Moon by Corinna Turner

From Carnegie Medal Award nominated author 

MANDY LAMB is one unique and highly entertaining story!

Mandy Lamb is the world's only half-sheep girl, thanks to a spot of well-meant but ill-advised genetic tinkering. She's grown up happily in the Valley of Worth with friends both sheep and human—and one who is neither.

Now she's off to senior school in the nearby town. And she's about to meet James, a rather strange orphan who smells, to Mandy, distinctly like a dog, and who has a bad habit of running off at the full moon.

With danger on the way, will James prove friend or foe?