A Very Silent Night, said to be recorded at a frequency that can be heard only by dogs, was issued as a charity CD by the Royal New Zealand Society for the Prevention of Cruelty to Animals.
To widespread surprise, it rocketed to the top of the charts, reports the Daily Telegraph.
Now distributors in the US and Australia are vying for the rights to international sales, the society has announced.
Although dog owners sit through several minutes of silence while the disc spins on the CD player, the dogs they own are reported to wag their tails, prick up their ears, and even dance in delight.
The accompanying video, which has become a popular feature on YouTube, shows Dei Hamo, a New Zealand singer, and two female companions mouthing the words of the song.
The CD was the brainchild of DraftFCB Creative, an Auckland-based advertising agency, which claims the recording was electronically synthesised to achieve the frequencies audible only to dogs.
Some remain unconvinced, however. Since the video appeared on YouTube, several viewers cast doubt on whether there is actually any sound at all.
One said: "This is a have. I checked it with an oscilloscope and there is nothing there, it's just muted video."
But another countered: "That's amazing! I cranked my speakers up full volume and played this, and the dog across the road went ballistic!" (Daily Telegraph)