2 yrd old boxer snapping

[terris37]

I have a two 2 yr old fawn/white female boxer who is spayed. she normally very loving and happy. Lately she has been a bit nippy with my younger son who is 12. She has never acted that way with me or my older son. She has tried to nip at my husband and daughter. This weekend my nephew stayed over and she really wanted a piece of him. I do not understand her behavior. She did manage to get my son in his face once and has bit him on his hand on several occasions. I am really concerned about this mood change. Is there something I am doing wrong. Would appreciate any feed back.
Thanks
Terri

[kassa]

Take her to the vet immediately. An abrupt
change in behavior could be caused by anything
from a bad tooth or splinter in her paw to
some internal injury which is causing her pain and
making her strike out, to something like a brain
tumor.

Do not treat it lightly, but get help immediately.
If she has never done anything like this before,
she needs to be looked at thoroughly to see what's
going on.

Good luck.