Our cairn terrier, Warfield, has always had a tenuous relationship with garbage trucks and school buses. It took a few years, but I believe I finally isolated the problem. It has something to do with the sound frequencies produced by diesel engines. It’s not all large trucks with their rushing engines or squeaky brakes; it’s only those running diesel. Craig Leland shared a similar story of his bichon frise, Clark, who starts howling whenever he hears a Luna carpeting ad, Bill Joel’s “Piano Man,” or Aerosmith’s “Dream On.”
I read somewhere that dogs don’t have a wider range of hearing than humans. It’s just that they can hear the higher and lower frequencies at much lower decibel levels than we can. I have no idea how that fits with the way a dog whistle works. Whatever the case may be, Warfield and Clark are hearing something they don’t like, and they’re set on letting us know.