Thought of a couple more things. Turid Rugaas book "Calming Signals" should be a must read. Learning to read subtle stress signs can help you better determine more specific triggers.
Also teach a highly rewarding or engaging game to help "snap" your dog out of his fear mode. Tugging or something similar can be developed over time to be a very reinforcing behavior that you can use to pull your dog out of a fear mode, it takes time and effort and may not work for extreme stress, but it will help with the borderline situations. Get this on a heavy reinforcement history and build it in to a great game (it can be any trick or game your dog adores). As long as it throughly engages your dog and your dog really enjoys it. At first your dog may not play or tug during stress but keep working it, it will build over time.
Dawn
U-CD Cammcastle's Mystic Riven CDX OAC OJC OGC OAJ NA TT CGC
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