Ear Protection for Dogs in Helicopters
We looked at ear protection years ago primarily with police canines that do routinely fly and train in helicopters. The concussion did not seem to cause any problems. This was possibly due to the type of helicopters i.e. smaller helicopters. I have been involved in military exercises, several years ago, and we discussed the issue and as long as the dogs were not in the direct prop wash the concussion is minimal.
I guess if you had a large transport helicopter and were directly in the prop wash it could be an issue.