Agree with the coins in the can, or clapping loudly to distract them.
It may sound harsh also but maybe when you're out on walks and you pass a big dog... bring a spray bottle with you and give a quick squirt in the face whenever he begins barking at a large dog. Don't let him see where the spray comes from though. Just do it quick. Most dogs do not like this! It will make him associate barking with the big dogs = water in the face (or wherever).
Also, I would take him around more large dogs off-leash to let him get used to bigger dogs. Sometimes the leash causes tension. |