We adopted a greyhound 2 weeks ago. He's warmed up to me the most so far, but still is clearly nervous when someone in our household returns home.

Over the past 2 days, our grey has taken to barking at my brother-in-law exclusively. If our grey hears my BIL leave his bedroom and go to the bathroom, he barks from downstairs. If BIL comes downstairs, he barks and growls and is obviously stressed by his presence.

My husband is currently out of town so I realize that may also be a stressor but ultimately I am looking for any suggestions on how to handle this situation. To my knowledge, BIL has done nothing wrong to our grey.

Thanks in advance.