2. Materials and Methods
Conflicts of Interest
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|Authors, Year, Ref||Population||Location||Intervention||Measures||Result|
|Wells, Graham, Hepper 2002 ||n = 50|
male: 27 neutered
female: 23 spayed
Age from 6 m–6 y
|Rehoming Center, UK||Five treatments:|
2. Human conversation (radio program);
3. Classical music (mix of tracks);
4. Heavy metal music (mix of ‘Metallica’ tracks);
5. Pop music (mix of tracks).
Dogs exposed to each of the five interventions on five separate days, with one day rest in between. Acoustic stimuli presented between 10:00–14:00.
|Three behavioral parameters observed: Position in kennel, activity, and vocalization. |
Dogs observed at 10 min intervals for duration of intervention.
|More time spent at front of kennels during all auditory interventions.|
Changes in activity and vocalization related to type of auditory stimulation—more time resting and quiet when exposed to classical music.
Increased barking during heavy metal music exposure.
|Kogan, Schoenfeld-Tacher, Simon 2012 ||n = 117|
1. rescue dogs
male: 21 neutered
female: 12 spayed, 1 entire
Mean age 5.27 y
Dachshund (pure and cross)
2. short-term boarding
male: 31 neutered, 10 entire
female: 38 neutered, 4 entire
Mean age 5.92 y
Variety of pure and mixed breed
|Dog shelter and boarding facility, USA||Four treatments:|
2. Classical music (4 tracks);
3. Heavy metal music (3 tracks);
4. Dog relaxation music (Through a dog’s ear (TADE)).
45 min exposure, followed by a 15 min break. Three conditions tested per day between 09:00–12:00
Dogs exposed over 4 months, not all dogs exposed to all treatments.
|Three behavioral parameters observed: Activity, vocalization, and body shaking.|
Dogs observed at 5 min intervals for duration of intervention.
|No interaction between treatment and group (rescue vs. boarding dogs), although rescue dogs spent more time sleeping and silent.|
Changes in activity and vocalization related to type of auditory stimulation—more time sleeping and quiet when exposed to classical music.
Increased body shaking during heavy metal music exposure.
|Bowman, Dowell, Evans, Scottish 2015 ||n = 50|
male: 25 neutered, 9 entire,
female: 12 spayed, 4 entire
Age from <1 y to >10 y
Variety of breeds, high proportion of Staffordshire bull terriers
Aggressive dogs excluded
|Animal rescue and rehoming center, Scotland||Two treatments:|
2. Classical music (mixed tracks, low pitch and slow tempo)
Dogs exposed to one treatment for 7 days, then the alternate treatment for 7 days.
Acoustic stimuli presented between 10:00–16:30.
|Three behavioral parameters: Position, location, and vocalization.|
Heart rate variability.
Observations made for 1.5 h, 2x/day (10:30–12:00 and 14:00–15:30), on days 1, 7, 8 and 14.
Saliva collected at the end of each 1.5 h period.
|Classical music exposure induced changes in behavior (less time standing and barking) and altered heart rate variability, indicative of reduced stress.|
No significant changes in salivary cortisol.
Resistance to effects of music if the same playlist is used repeatedly.
Therapeutic effects of music more obvious in male dogs.
|Brayley, Montrose 2016 ||n = 31|
male: 24 neutered
female: 7 spayed
Age from 9 m to 13 y
|Rescue shelter, UK||Five treatments:|
3. Classical music (Beethoven);
4. Pop music (mix of tracks);
5. Dog relaxation music (TADE).
Dogs exposed to each treatment for 2 h, with 2 days rest in between.
Acoustic stimuli presented between 10:00–12:00.
|15 behaviors sampled, including multiple measures of activity and vocalization.|
Behavior recorded every 5 min using an ethogram.
|Audiobook treatment induced calmer behavior than all other treatments.|
Classical music induced calmer behavior than pop music and no intervention (control).
|Albright, Seddighi, Ng, Sun, Rezac 2017 ||n = 10|
male: 8 neutered, 2 entire
Mean age 4.2 y
|Veterinary hospital, USA||Five treatments:|
1. negative control (saline);
2. positive control (sedative);
3. Human voice quiet (55–60 dB);
4. Human voice loud (80–85 dB);
5. Dog relaxation music (TADE) (45–50 dB).
Dogs exposed to treatment for 20 min after sedative injection.
Each dog exposed to all treatments with a minimum of 48 h rest in between.
Testing between 08:00–15:00
|Depth of sedation assessed by spontaneous behavior, accelerometry, and restraint tests.|
Behavior assessed every 5 min and compared before, during and after treatment.
Restraint tests 30 min and 40 min post-treatment
|Sedation is negatively impacted by high-intensity noise conditions (80–85 dB)|
Exposure to music marketed as having a calming effect in dogs did not improve sedation
|Bowman, Dowell, Evans, Scottish 2017 ||n = 38|
male: 15 neutered, 9 entire,
female: 7 spayed, 7 entire
Age from <1 y to >8 y
Variety of breeds, high proportion of Staffordshire bull terriers
|Animal rescue and rehoming center, Scotland||Six treatments:|
1. Control (before and after);
2. Soft rock;
4. Pop music;
5. Reggae music;
6. Classical music
Dogs exposed to a different music treatment each day for 5 consecutive days.
Acoustic stimuli presented between 10:00–16:00.
|Three behavioral parameters: Position, location, and vocalization.|
Heart rate variability.
Observations made for 1 h, 2x/day (10:30–11:30 and 14:30–15:30).
Urine collected between 13:00–14:00 on days 1, 4–8 and 11.
|Music exposure (all genres) induced changes in behavior (less time standing) and altered heart rate variability, indicative of reduced stress.|
Urinary cortisol higher during soft rock exposure.
Physiological and behavioral changes were maintained over the 5 d of auditory stimulation, suggesting that providing a variety of different genres may minimize habituation.
|Engler, Bain 2017 ||n = 74|
no further information supplied.
|Veterinary teaching hospital, USA||Three treatments:|
2. Classical music;
3. Dog relaxation music (TADE)
Treatment rooms assigned to each treatment. Music played continuously throughout the day. Each dog only exposed to a single treatment (control = 30, music = 23, TADE = 21)
|Owners and clinicians completed a standardized survey regarding dogs’ behavior.|
Physiological variables obtained from the medical record.
|No difference in behavior (aggression, anxiety) or physiology (body temperature and heart rate) of dogs detected.|
Classical music had a positive effect upon owner and employee satisfaction.
|Alves, Santos, Lopes, Jorge 2018 ||n = 67|
Puppies (7 weeks old)
Four different breeds (27 German shepherd dogs, 19 Belgian Malinois shepherd dogs, 7 Dutch shepherd dogs, and 14 German shepherd dog and Belgian Malinois shepherd dog crosses).
|Police canine unit, Portugal||Two treatments:|
1. Control (n = 46);
2. Varied auditory stimulation (including music, radio talk shows, and environmental noise (cars, sirens, gunshots)) (n = 21)
Auditory stimulation provided from 3 weeks of age for 2 h/day, focused around meal and play time.
|Puppies’ performance in a skills test (9 scenarios ranging from following and submission to startle response and pain sensibility) evaluated at 7 weeks of age.||Auditory stimulation had a negative effect upon puppies’ performance overall, in particular on following, lifting by evaluator, and submission tests.|
|Koster, Sithole, Gilbert, Artemiou 2019 ||n = 16 (8 kenneled, |
Mean age 3 y
81% mixed breed
|Veterinary teaching hospital, West Indies||Two treatments:|
2. Dog relaxation music (TADE)
All dogs exposed to one treatment for a 60 min veterinary training session, then 7 days later exposed to the alternate treatment.
|Heart rate variability||Auditory stimulation reduced RR variability, suggesting the novel music exposure had an excitatory rather than a calming effect.|
|Uetake, Hurnik, Johnson 1997 ||Holstein cows (Bos taurus)|
n = 19 (mid and late lactating)
|Dairy Research Center, Canada||Cows conditioned to identify the start of the milking period when they heard music (Country music)|
During experimental period cows observed on days with and without music stimulus.
|Number of cows in holding area|
Behavior (standing, eating, resting)
|Music stimulates the voluntary approach of cows to holding area and encourages behavioral readiness of cows to milking|
|Nunez et al. 2002 ||BALB/c mice (Mus musculus), and Sprague–Dawley rats (Rattus norvegicus domestica)|
n = 80 mice (male 7–12 weeks old)
|Lab animal facility, Spain||Four treatments:|
3. Auditory stressor (fire alarm bell);
4. Auditory stressor and music.
|Mice: Immune function (e.g., thymus and spleen cell counts and viability, T cell proliferation)|
Rats: Injected with carcinosarcoma cells and sacrificed 8 days later to count the number of metastatic nodules on the lungs.
|Music enhanced immune parameters and anti-tumor response in unstressed rodents.|
|Lemmer 2008 ||Wistar-Kyoto rats (Rattus norvegicus domestica)|
n = 20 (male, 10 normotensive and 10 hypertensive)
|Lab animal facility, Germany||Four treatments:|
2. White-noise control;
3. Stress response control (cage-switch);
4. Classical music (Mozart/Ligeti)
|Radiotelemetry to monitor blood pressure, heart rate, and motor activity.|
Plasma norepinephrine concentrations
|Mozart and Ligeti had different effects on physiology, with more effects detected in hypertensive rats.|
White noise induced no effects.
|Davilla et al. 2011 ||Layer chicks (Gallus gallus domesticus)|
n = 192 (8 breeds)
|Conservation program experimental station, Spain||Two treatments:|
2. Classical music (Mozart’s string quartets)
|Fear (tonic immobility duration)|
Stress (heterophil to lymphocyte ratio and fluctuating asymmetry)
|Significantly higher heterophil to lymphocyte ratios in chicks reared without music.|
Significant differences in physical trait measurements (wing length asymmetry, leg width, and combined asymmetry) in birds reared without music.
Inconsistent, insignificant effects of music on duration of tonic immobility.
|Wallace et al. 2013 ||Moloch gibbons (Hylobates moloch)|
n = 8 (2 family groups)
|Wild Animal Park, UK||Two treatments:|
2. Instrumental classical music between 50–90 bpm
Affiliative behavior (grooming)
Stress behavior (self-scratching)
|No significant differences in behavior between music and control treatments.|
|Li et al. 2019 ||Piglets (Sus scrofa domesticus)|
n = 35 (males from 14 litters)
|Commercial sow farm, China||Five treatments:|
2. String instruments, slow tempo (65 bpm);
3. String instruments, fast tempo (200 bpm);
4. Wind instruments, slow tempo (65 bpm);
5. Wind instruments, fast tempo (200 bpm)
Piglets given choice between rooms with and without music.
|Entries to room|
Behavior (lying, standing, walking, exploring, feeding, playing, tail wagging)
|Piglets spent significantly more time in the slow/string and fast/wind rooms compared to the other music conditions.|
Behavioral responses varied with music treatments—stronger response to tempo than instrumentation.
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