Smart assed answer. Turn off the TV.
Real answer. Maybe a dog trainer. There was a dog whisperer about that exact problem.
OMG...I have a Shih Tzu, and she barks at the t.v., too....I think it's cute....part of her personality...and apparently, your dogs' too....If it really bothers you, you can shut the t.v. off, and put on some music, but then, you are left, unable to watch your own t.v.
They are protecting their home...they have no way of knowing that the barking isn't a threat.....
Usually, when there is an unwanted behavior, if you fill a can with screws, put a lid on it....then, when she/he barks, drop the can (don't let your dog see you drop it)....she/he won't know where that came from, it will be an unpleasant startle....and they will begin to associate that noise, with their behavior(barking)....and they'll avoid it, because they don't like that noisy can....Make sure you are consistent, though, or it won't be effective.
turn off the TV it is rotting his brain...
Why stop him... encourage it, it'll become his little game
I am with rjcrjc
Limit his TV viewing time... and maybe use the parental controls not allowing Animal Planet. Do not let him Watch Best in Show either. I really have no idea how to stop it unless you change the channel.
change the channel
Get him a doggie friend.
as h does it, tell him quiet. if he gets quiet, even for a few seconds, give him a treat. continue doing that until he gets it himself