what to do?

Question
I have a alomost 8yr old gsd.  She's imported.  I have a male also/fixed of course his age is 5 yrs old.  Just inherited a pup gsd for mothers day.Im not new to the training, and i know the pecking order in the house.I know i'm the pack leader. the pup seeks acceptance at every turn w/ the older gsd. Today my  8yr old went after the 5 month old pup... i kenneled the 8yr old and while i was doing this, she turned on me by showing teeth to me and growling. she has never done that before.I had her since she was 7wks old....she has traveled the world w/ me.Im at a loss.  not sure what to do with the aggression towards me or pup.  What can i do different?  any suggestions?  she is also a family pet and is adored in all ways.  help me if you can.

Answer
This is 2 part question.   First her behavior to the pup.  I am not sure what you mean by "going after" the pup.  Did she pin him, was is all growl and no real bite, or was she seriously going to make a few holes in him?   Adult females will often tolerate a young pup until they push too many buttons....  then will teach him a lesson by pinning him.  But usually it looks and sounds really bad but the pup will get up with only his pride damaged.   You will have to figure this one out.   Let them play, supervised of course but don't be overly protective.   See how she reacts.   She may be a bit jealous, so spend time with her alone.   

Now for her behavior to you, she was probably just a bit hyped and over stimulated, as she has not shown this behavior before.  Could she be in any pain????   Arthritis etc and when the pups bumps her she could be reacting to some pain that you are not aware of.  I am just throwing things out there for you to consider as I can't see the dog.   Watch for any other signs of inappropriate behavior on her part in case you've missed them while your attention has been on training the new puppy.

Good luck,

Lori