7 month old picking on 9 week old puppy

[jemarrs]

Hi, I'm a newbie to forum participation as well as to having a German Shepherd puppy.
I adopted a puppy when he was 9 wks old to be a companion to my 71/2 yr old Lab. Sadly, my beloved lab passed away suddenly at the beginning of the year to cancer. Just a couple of days ago I adopted my GSD puppy's half sister at 9wks. I have been shocked at how awesome the German Shepherd breed is!
I'm a bit shocked at how my 7 mo puppy is reacting to the 9wk old puppy- trying to be extremely mouthy in a very aggressive manner.
Also, I had had the choice of the last two puppies in the litter-the 'runt' of the litter who was extremely affectionate, eye discharge, and her sister who wasn't affectionate per se, with two big red mask markings around her eyes (otherwise mostly black)and much more sturdy. I chose the more robust one and went to pick her up on Friday after a month's time. The one that was there for me is extremely small with eye discharge and is extremely affectionate. Of course, it was love at first site, but was the wool pulled over my eyes? Can a puppy lose such a distinctive marking like a red mask and go to black? I always had heard that black can go to other marking but not the other way around Thanks!!

[Mary Beth]

Your 7 month gsd is acting normal - he is the oldest now and will not let a little puppy rule the house. Watch them so that the puppy doesn't get hurt and keep them separated if needed. I don't think a puppy can lose such a distinctive marking - it almost seems that you were given a different puppy. If you are happy with the puppy, then fine, if not, you may want to return the puppy and get a refund.

[jemarrs]

Thanks so very much for your reply!

[qbchottu]

What do you mean "red mask"? You have a picture?

You have 2 puppies under 1 year in your house - you have to manage the dogs with greater care. They need to be separated, train separately, bond separately, create an environment where the 9wk and 7mo are able to individuate and develop independently of each other. You need to closely monitor and separate the dogs if one is getting too much. You can set your younger one up for failure if you continue to expose her to frightening and overwhelming experiences with other dogs at a young age...