My senior is 10.5 y/o. Czech border patrol working lines: an FCI world championship trainer once described him as a "real dog" in a schutzhund seminar. He was the most socially dominant dog in the neighborhood. Nerves were never the most solid but combined with his drives, natural aggression and social dominance gave him that edgy demeanor in protection. In the last year or so he had become more mellow. Yesterday, he got out of our fenced in acreage to chase coyotes but it seemed that for the first time in his life, the coyotes chased him back to our property whereas they all used to be afraid of him. Today, he was scared of thunder and insisted in being let inside the house again for the first time in his life for that reason. Anyone else experienced a once dominant dog losing his nerve and courage in seniority?