I love dogs, please keep this in mind.
Today while shooting dogs at YHS a pair of devils emerged. Devil #1 was caught in the act by Gary’s camera. They are sisters, litter mates, who came in to the shelter together. Apart they were fine, almost calm (not common in the shelter environment). But when we brought both of them into the photo shed, things went south. Gary described the racket as a “sound track to a horror movie”. I have never heard dogs generate this sound, it was like quacking ducks screaming and barking. And it was loud, overwhelmingly so. Loud as gunfire. It lasted a few long minutes, all the humans were thinking of running for the door.
My experience with dogs that live together is they will calm each other when they’re near each other. They feel safer with a pack mate at hand. I can’t say how these two felt, but they got very loud.