I have a problem with my armature. if I symmetrize the other side of the armature is outside the model.

If I drag it inside the model and do weigth painting the side I draged is all wrong and deformed. what am I doing wrong?
Here's the beld file
The symmetrize will use the armature's origin as the axis center, to fix your problem you could for example align the armature's origin to the dog's origin: