I have a nearly 2year old, neutered male shih tzu. When he was younger he was playful, never barked and friendly with all dogs. In the past 6 or 7 months there have been 2 incidents where other dogs off-lead have come over and 'had a go at' him when he was onlead. One was a very scary incident where a great dane picked him up by the neck and was shaking him.
Now Fred is quite wary of a lot of dogs and sometimes goes crazy barking at other dogs we pass - especially if the other dog barks first. He seems quite on edge with certain dogs and sometimes dives toward them and it makes me on edge walking him incase he goes any further than barking. Is there anything I can do to help calm him and undo the damage of the 2 negative experiences?