Savage Sanctuary by Jacqueline Barbary

Blurb:
Sexy bad boy shapeshifter Michael O’Dare grew up on the streets. When government soldiers finally captured and imprisoned him, he became a lab rat and a collared slave, never again allowed to be human. His escape allowed him to return to human form and head for freedom in the Western Territories.

Robert Hamilton-Scott had lived by the code "You’re careful, or you’re caught" for too long to take chances now. The one risk he takes in his carefully controlled life is offering temporary shelter to shifters on the run like Michael.

Robert knows it’s definitely not safe to want the sexy renegade he’s giving sanctuary to-passion is dangerous for a shapeshifter. As the soldiers close in he must choose between the careful life he’s built or life on the run with the man who has captured his heart.