Why was Enzo alone and locked in the house in art of racing in the rain?

In "The Art of Racing in the Rain," Enzo is left alone and locked in the house because his owner, Denny, is facing a difficult situation involving a custody battle over his daughter, Zoe, and is dealing with the aftermath of a family tragedy. Denny is preoccupied with the legal challenges and emotional turmoil, which leads him to leave Enzo alone for extended periods. This isolation highlights Enzo's loyalty and his desire to support Denny during tough times, emphasizing the bond between them.