I think he will be ok, as long as your brother gives him the proper exercise. My brother also has a boxer...I think he is about a year now too.. and he lives in a TINY apartment with his wife. The do take their pup, Dude, out a lot, and he was very well trained the last time I saw him...(about a year ago) He is very interesting.. my brother taught him in German (or whatever langauage they use with police dogs) so you have to say different things, you can't just say, sit, lay down..etc. I hope everything works out!