I just want to welcome you to YorkieTalk!!
You have some good advice. Please don't take offense to all the opinions. This is a great place. I would say if what you're doing isn't working after this amount of time, do try something else.
My little Roxie likes to bark at squirrels and other dogs, it does take time to train them to curb the behavior.
yorkiesmiles &
Bubba &
Roxie