Just take it slowly, the way you did when he went through the first Fear Period at 8 weeks. (raisingrascal.com)
If you get a dog 18 months or older, they have gone through fear periods and you have a pretty good idea what the working ability will be like. (servicedogtraininginstitute.ca)
Unfortunately, few breeders or new puppy owners understand how to raise a confident dog and the importance of fear periods. (professorshouse.com)