Some months back, a piece in our blog series mentioned using music to ease your pet’s anxiety during the process of euthanasia. It was a casual suggestion aimed vaguely at minimizing the uncertainty and fear that may accompany my patient on this, his final visit to my clinic. The idea of using music on veterinary patients has been wiggling around in my brain since then. I haven’t attempted it yet; could that prove to be a useful tool?
There are a limited number of studies on music perception in animals, which are further limited by the fact that human researchers have difficulty reading the minds of their non-human subjects. Some information was gathered by brain imaging, some by hormone assays on body fluid samples. Some projects collected only heart rate and body temperature. In others, minutes of standing up and lying down were tabulated. Some poor soul had the job of counting barks emitted. Furthermore, the music stimuli employed were extracted from broad categories such as “soft rock” and “classical”. Anyone who’s spent two minutes listening to music will realize immediately that sorting it into categories doesn’t follow a simple, generic algorithm. Put another way, two music aficionados may quickly fall into a debate on the exact genre of a particular piece. Put a third way, one tune dallies along with a handful of butterflies just until Elmer Fudd makes his first appearance, while a different specimen is trotted out for your Independence Day fireworks finale. Both are inarguably (...right?) classical music, but they are carefully selected for the wildly different responses they inspire in the audience.
(Is it driving you crazy? They are Grieg’s “Morning Mood” and “1812 Overture” by Tchaikovsky.)
To further confuse the issue, animals of different species vary in their ability to perceive and process sound energy. Most animals have hearing more acute than ours, with the capacity to detect sounds that are too soft for humans and pitches that are either way too low (whales and elephants, for example) or way too high (bats and dolphins) for the human ear. This means that “human music” may prove to be totally inappropriate (i.e., irritating) in terms of pitch or volume, or the inclusion of “invisible” sounds.
A few research groups have tackled that issue by attempting to create sound palettes tailored to a particular species. Pitches are selected to match the physiology of the subject’s auditory apparatus, as noted above. Tempos are generally chosen to match the target species’ innate biological rhythm, since it’s widely believed that a beat matching one’s own resting heart rate exerts a calming influence on listeners. Results were somewhat encouraging in felines; dogs presented more of a challenge.
We actually know so little about the concept of “music”. One man’s trash is another man’s treasure, and so forth. Music can make us cry, bounce, close our eyes in ecstasy, or consider throwing ourselves out of a moving vehicle. It’s impossible to quantify. If we can’t comprehend music itself, how can we hope to understand the route it may take through a non-human ear and brain?

Dr M.S. Regan