Welcome to the forum and congrats to your new addition...What's your little one's name?
Boxers are the best..They will make you cry, make you laugh and sometimes will make you feel like you are losing your mind.. :bsjoke: .Lol ..But I wouldn't ever be owned by any other breed...
The diaherea may not be nothing..Any time you change a dog's enviroment for whatever reason, it sometimes will take a bit for them to adjust...Boxers especially are highly senstive to change and with a puppy, even more so...Are you feeding the same food that he was? Any food changes can cause that also...
Whining at first is VERY normal..Are you crating him? Take a hot water bottle and fill it up and put it in his crate. Also you can use an old fashion wind up alarm clock, they like the ticking sound..I used to leave the radio on real low on a jazz station for mine....If you are crating him, don't fuss over him once he's in, leave him be..Eventually the whining will stop..Altho to you it seems like it never will..Believe me, it will get better...When we brought Buck home, it got soo bad, my ex went and got him out of the crate and took a blanket and they slept wrapped up together on the patip one nite...Your puppy is missing his family, so you have to become his family to him....
Until he's had all of his shots, I would keep him on your property..No walks..The rule of thumb is 5 mins for every month of age..He needs time for his bones to completely develop, so rigorous exercise needs to be kept to a minimum...Ig your yard is fenced, definitely let him have the freedom of running around in his own yard..I think Buck was close to a year before I started taking him on long walks...
Hope this was some help and definitely read thru our puppy section..We have a ton of new puppies on here and there is a lot of very good information in there.....Welcome to Boxer Forums......