Dog Appeasing Pheromone 3
Elaine Tod, , Donna Brander and Natalie Waran
Animal Behaviour and Welfare Group, Division of Animal Health and Welfare, Royal
(Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Veterinary
Centre, Easter Bush, Roslin EH25 9RG, Scotland
Accepted 21 January 2005. Available online 17 March 2005.
Abstract
The behavioural effects of dog appeasing pheromone (DAP) continuously administered
over a 7-day period, were evaluated in adult dogs housed in a public animal shelter.
Barking amplitude (dB) and the frequency of discrete behavioural responses to two
temperament tests associated with fear, separation and excitable behaviour (Arrowsmith,
unpublished data) were recorded in 37 treatment and 17 control dogs. Mean barking
amplitude (Leq) and barking frequency were significantly reduced in dogs subject to DAP
exposure for 7 days (P < 0.001, <0.04, respectively), though peak values (Lpeak) were
not significantly altered. There was also some reduction in the barking amplitude of dogs
during the 1 min recovery period, following a distraction. Following 7 days of DAP
exposure, there were significant differences in resting (P = 0.03), barking (P < 0.04) and
sniffing frequency (P = 0.01) in response to a friendly stranger. There were no highly
significant differences in response to a neutral stranger. The preliminary tests indicate
that DAP is a useful palliative tool for reducing some behavioural indicators of stress in
dogs. Further tests are necessary to investigate the use of DAP in canine stress reduction
in conjunction with traditional behavioural therapy programmes.
Keywords: Dogs; Stress; Pheromones; Behaviour; Separation; Kennels
Article Outline
1. Introduction
2. Materials and methods
2.1. Animals
2.2. Experimental tests
2.3. Barking amplitude in response to a distraction
2.4. Behaviour tests
2.5. Neutral stranger test
2.6. Friendly stranger test
2.7.Statistical analysis
3. Results
3.1. Barking amplitude in response to a distraction
3.1.1. Walking test data
3.1.2. Recovery data
3.2. Behavioural tests
3.2.1. Neutral stranger test
3.2.2. Friendly stranger test
4. Discussion
Acknowledgements
References
1. Introduction
Veterinary surgeons in the United Kingdom reported that many of the behavioural cases
presented to them in 2002 were separation or fear related. Many of the problem
behaviours experienced by dog owners and kennel workers are due to this phenomenon
(APBC, 2003). Behaviours such as excessive vocalisation, destructiveness, inappropriate
elimination and excessive licking are widely thought to be coping mechanisms for the dog
when separated from the owner, and are key diagnostic criteria in the identification of a
dog suffering from fear or separation related problems (CEVA Santé Animale; Sheppard
and Mills, 2003).
It is common for such symptoms to be managed through a programme of behavioural
therapy. However, this approach requires commitment and regularity in the household
routine, and often a deliberate weakening of the owner—pet bond in the case of separation
related problems. This can sometimes prove challenging for the owner who has difficulty
in reducing contact with the dog, and also in homes with multiple occupants where it is
difficult to enforce changes in routine (Mugford, 1995 and Podberscek and Serpell, 1999).
In circumstances where dogs do not respond to behavioural therapy, pharmacological
agents can be prescribed to manage the dog's behavioural symptoms e.g. Amitryptiline,
and Clomipramine (King, 2000). Such treatments can have sedative effects due to their
cerebral suppressant properties (Sari et al., 1975, King, 2000).
The field of mammalian pheromone research established itself primarily in response to a
study on boar pheromones which were shown to induce immobility in the sow during
oestrus (Watson and Radford, 1960). This landmark study demonstrated the potential
benefits of producing synthetic analogues of pheromones (Pearce et al., 1988, Pageat and
Gaultier, 2003). Pageat (1999), who discovered the production of DAP in lactating dams,
was the first to artificially synthesise this pheromone in dogs, opening up the possibility of
using appeasing pheromones in a clinical capacity to tackle fear and separation problems
in dogs. A similar product called “Feliway”, developed for cats and based on feline facial
pheromone secretions, has also been received with interest by the scientific and
veterinary community.
The natural form of DAP is produced 3 days following parturition by the lactating dam
(Pageat and Gaultier, 2003). The pheromone vaporises when combined with saprophytic
bacteria present in the skin. This bacteria is important in increasing the volatility of the
pheromone, which is then released from the intermammary sulcus directly into the
atmosphere as an air-borne molecule (Pageat and Gaultier, 2003). DAP is then absorbed
by the puppies through a paired olfactory structure, present in the nasal cavity, called the
vomeronasal organ (VNO). It is this structure which transduces the pheromonal signal to
the amygdala and hypothalamus (Pageat and Gaultier, 2003). The neurological pathways
involved in the transduction of this appeasing signal are not completely understood,
however recent research has highlighted the importance of pheromone binding proteins,
(PBPs) present in the nasal mucus, as being important in the uptake of DAP (Pageat and
Gaultier, 2003). Synthetic DAP is administered into the air through an electrically heated
diffuser, and is understood to work equally well on puppy and adult dogs alike, although
definitive research has not been conducted to date, on this question (CEVA Santé
Animale).
As it is not a cerebral supressant, it does not have the side effects described above for
some pharmacological agents and has been proposed as a ‘natural’ way to reduce fear and
stress related behaviours in dogs. Recent research by Sheppard and Mills (2003) has
demonstrated that DAP has the potential to be of use in situations which owners
commonly report as acute stress factors for dogs, in particular the use of fireworks. No
controlled trials investigating the efficacy of DAP to calm dogs exposed to potentially
stressful situations have however been published to date.
Dogs with behavioural problems are frequently given up to shelters as a last resort when
the owner can no longer cope (Voith and Borchelt, 1996 and Voith and Ganster, 1993). On
being relinquished to an animal shelter, the dog's behaviour can often worsen, reducing
further the chance of being successfully re-homed. Dog shelters are widely reported to
exacerbate, problem behaviour in dogs (Hennessy et al., 2001, Sales et al., 1997 and
Hennessy et al., 1998). Even in well run shelters, the intrinsic problems of noise, novelty,
change in routine, lack of visual contact with other dogs and an unpredictable
environment; are all considered to be psychological stressors which can result in fear and
stress related behaviours as described above (Hanson et al., 1976 and Hennessy et al.,
1998).
The aim of this study was to investigate the efficacy of DAP as a potential stress reducing
aid by measuring vocalisations of dogs and recording the behaviour of shelter dogs in
response to scientifically validated behavioural tests (Arrowsmith, unpublished data) in
the absence and presence of DAP. A Scottish SPCA animal shelter was chosen as the venue
for this study.
2. Materials and methods
2.1. Animals
This study was undertaken at a Scottish SPCA Animal Welfare Centre in Dumbarton,
Scotland. Three separate kennel blocks, similar in design and layout, provided control of
pheromonal distribution through separation of blocks via doors and corridors. The study
animals were housed individually in wire mesh fronted holding pens, and were allowed day
time access to an attached outdoor kennel run via a small door in their indoor pen, except
during a short period of time for kennel cleaning. Each kennel measured 1.6 m × 1.0 m (l ×
w) for the indoor section, and 3.9 m × 1 m (l × w) for the run. A total of 37 treatment dogs
and 17 placebo/control dogs of random age, gender, breed and life history were tested in
this study, the only discrimination being that no dogs were undergoing behaviour therapy
or psychopharmacological intervention, also that young puppies under 6 months of age
should not be used.
2.2. Experimental tests
The study was blind, randomised and placebo controlled as the test administrator was not
aware at time of testing which dogs were in the control group. All dogs were tested
individually. The DAP electrical diffusers were labelled A–C and an assistant kept a record
of which letter constituted the control diffuser, which had a rinsed, empty pheromone
bottle attached to it. All pheromone bottles were covered to ensure the placebo diffuser
could not be visually identified by the tester. All behavioural tests conducted were
adapted from a set of scientifically validated temperament tests suitable for measuring
discrete behavioural traits associated with fearfulness and separation anxiety
(Arrowsmith, unpublished data) and were performed without direct physical contact with
the dogs. For all dogs, control and experimental, baseline data was recorded at day 0
before the DAP diffusers were plugged into the electrical sockets and data for comparison
was then recorded on the same dogs following 7 days of exposure to the pheromone. The
electrical diffusers were placed above the internal pens and each kennel block had one
DAP diffuser which covered an area of up to 70 m2 which was deemed more than
adequate for the internal dimensions of each kennel block (CEVA Santé Animale). A 1-
week trial was conducted before the study commenced to ensure all tests and recording
procedures were adequate. During the actual study, testing was employed over a period of
10 weeks, in order to gain enough dogs for this study, please see table one for details. A
wash out period of 7 days was employed between each batch of testing to ensure that any
remaining pheromone circulating in the air of each kennel block was given ample time to
dissipate from the environment before baseline data was recorded for the next batch of
dogs, given that DAP is a chemical with low-volatility and therefore a low rate of
dissipation. Each individual dog was given a code number to aid identification on return to
the kennel for the follow up data collection at 7 days. Details such as breed, age, sex and
colour were also recorded. Each dog was only tested once during this study.
2.3. Barking amplitude in response to a distraction
All measurements of sound pressure level (amplitude) were made in dB, using an A-
weighting scale to cover sound in the 0.5–10 kHz frequency range (low frequency),
because most of the energy in a dog's bark, as well as the dog's auditory sensitivity is
centered in this frequency range (Peterson, 1980 and Sales et al., 1997). The maximum
barking amplitude in each block was recorded (Lpeak), as was the average amplitude over
the one minute recording session (Leq). All recordings were made using a Realistic 33-
2050 © sound meter with a range of up to 126 dB (Table 1).
Table 1.
Number of placebo and treatment group dogs per week of data collection Week no. No. of
dogs
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Placebo
--------------------------------------------------------------------------------
Treatment
--------------------------------------------------------------------------------
1 3 6
2 4 2
3 2 7
4 5 13
5 3 9
Total 17 37
The average barking amplitude for each kennel block, collectively, was recorded at the
start of each session and with the observer out of the dogs view. The observer then walked
up and down the kennel block at a steady pace, avoiding eye contact with the dogs, in
order to act as a distraction. The barking amplitude was then recorded every 5 s. The
observer, again, then moved out of visual contact with the dogs and recorded barking
amplitude for a further 60 s as an index of recovery time. It is important to note that all
three kennel blocks were constructed of the same materials, which helped to standardise
the acoustic levels, therefore maintaining uniformity for barking amplitude recording
between kennel blocks.
2.4. Behaviour tests
A behavioural ethogram (see Table 2) was used to record the frequency of discrete
behavioural categories correlated with a high intensity fear response (Sheppard and Mills,
2003, Shull-Selcer and Stagg, 1991 and Thompson, 1998) and behaviours indicating less
intense fear but still constitute a welfare issue for these dogs (Sheppard and Mills, 2003).
The following tests were administered randomly to the dogs to reduce the chance of an
order effect.
Table 2.
Behavioural ethogram Body postures and motor activity
Lying Ventral/lateral lying on ground with all four legs resting and in contact with ground.
Eyes may be open or closed
Sitting Hind quarters on ground with front two legs being used for support
Standing All four paws on ground and legs upright and extended supporting body
Walking Forward movement with legs resulting in shift of whole body to a new position in
enclosure
Posture low Head lower than shoulders, tail low, ears lowered
Vocalisations
Bark ‘Rough’ sound often repeated in quick succession
Growl Deep threatening rumble
Whine Sustained whimper
Displacement activities
Yawn Mouth open wide for a period of a few seconds, then closes
Lick nose Tongue extends upwards to cover nose, before retracting into mouth
Pant Mouth open with tongue extended accompanied with rapid breathing and
expansion/contraction of chest
Escape behaviour
Exit ‘rear’ <td class="nowrap" align="left
| Efficacy of dog appeasing pheromone in reducing stress and fear related behaviour in shelter dogs |