[From Tufts November 2012 Issue]
The head of our Behavior Clinic, Dr. Nicholas Dodman, was stumped by the case of a Blue Merle Collie experiencing panic attacks several times a day, seemingly out of nowhere.
“How often does it happen?” he asked the owner.
There was no set answer. The woman explained that with no particular rhythm to the episodes, the dog, named (appropriately enough) Blue, would begin panting and pacing and even salivating. Then the bout would pass and, a while later, without warning, would happen again.
Dr. Dodman wondered if perhaps there was some kind of noise that could be causing the frequent occasions of hyper-anxiousness, but Blue’s owner didn’t think so. She did offer, however, that whenever she and Blue went to her girlfriend’s house a few blocks away, and also when she left Blue there overnight, he never had the bursts of panic. Clearly, it was something about her own home that was driving Blue crazy, literally.
After Dr. Dodman and the owner wracked their brains trying to come up with the possible trigger — washing machine, white noise machine — she finally said, “Well, I do have a parrot.”
“So I asked her,” Dr. Dodman relates, “any chance you can take the parrot to your friend’s house instead of Blue and see if that solves the problem?’
“She resisted me for six weeks,” he says, “insisting that the bird wasn’t the issue. But she finally relented, reporting that when she did take the parrot to her girlfriend’s, the attacks stopped.
“Parrots can make screeching noises,” Dr. Dodman explains, “and we probably can’t hear all of the screeches in the uppermost range. But a dog can. It’s perhaps the auditory equivalent of fingernails being scratched down a blackboard.
“Now,” Dr. Dodman says, “when someone tells me about panic attacks in a dog that occur seemingly without any particular rhyme or reason, I suggest the person tape record the goings-on in the home. Sometimes, when you wind back the tape, you can hear something that happens each time immediately before the dog gets upset.”
It’s (almost) all in the frequency
The reason dogs hear sound with higher pitches than we can is that they are able to hear in the ultrasound range. That means they hear sounds with ultra-high frequency — some 50,000 cycles per second, as opposed to the human maximum of closer to 20,000 cycles per second. Practically speaking, that means a dog can hear two octaves higher than a person (a range that includes the sound made by a dog whistle).
The evolutionary reason for the high-pitched hearing is that rodents communicate with each other in those upper ranges. If, before dogs were domesticated, a dog in the wild needed to locate a rodent so he could eat it for sustenance, he could track it by listening for it.
Dogs can do more than hear upper notes that we can’t, however. They can also detect and localize sound with superb accuracy and discriminate better than we can between noises occurring at the same time. Their brains simply decode and translate sound signals better than ours. Indeed, a dog’s adult hearing patterns are in place by the time a puppy reaches the age of seven weeks — astounding when you consider that a puppy can hear hardly anything for the first two weeks of life because his ear canals are still closed.
Another auditory advantage dogs have is that their ears are relatively bigger and much more able to move about than a human’s. Dogs have some 30 muscles per ear as opposed to the nine in ours. All that muscle power allows them to move their ears in the direction of a sound and lets them zero in on it as accurately as possible — unless they have heavy flop ears like a Cocker Spaniel. All those muscles notwithstanding, a dog would be hard pressed to point such heavy ears in different directions. Still, even a floppy-eared dog can hear four times the distance its owner can.
No wonder your dog might go off half cocked for no apparent reason. He may be hearing something far away to which your ears are oblivious but that has grabbed his attention. Or he may be hearing something right in the house that gets him going, like Blue did. It’s no doubt why some dogs run under the couch when they hear the vacuum cleaner. They’re perceiving screeches in the machine’s noise that you are missing.
