The use of DAP collar to reduce stress during training of police dogs

(01.09.2005) A preliminary study

S. Schroll*, J. Dehasse1,  R. Palme2, I. Sommerfeld-Stur3, G. Löwenstein4

1 3 avenue du Cosmonaute, B-1150 Brussels, Belgium
2 Department for Natural Sciences/Biochemistry, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
3 Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210 Wien, Austria
4 Grub 1, A-3351 Weistrach, Austria
* Corresponding author: [email protected] - Hohensteinstr. 22, A-3500 Krems, Austria


In Austria, police dogs are given to their owners as puppies at 8 weeks of age. For the first one and a half years, the dog lives with the family and receives a basic education.

After this basic education, when they are 16 to 22 months of age, police dogs start an intensive training course for 15 weeks (7 and 8 weeks respectively, with a 3 to 6 week pause in between). During this training course, which is held at a special training center, the dogs stay in kennels, separated from their owners at night. During the working days, the dogs are trained extensively in various environments.

After the training course, the dog and its owner have to pass an examination before it is accepted as a professional police dog. This training course is therefore very stressful for both owners and dogs.

According to trainers and owners during previous courses in past years, the most prevalent signs of stress were: excessive barking and howling at night (in some cases, the whole night), increasing excitement, fatigue, lack of concentration at work,  weight loss, diarrhea, and salivation.

Isolation and social separation from familiar humans in a novel environment is considered a stressful event for a highly social species such as dogs. (Tuber et al 1996). The absence of the human attachment figure combined with a novel environment, causes some adult dogs to exhibit behavioral signs such as vocalization and physiological changes including the activation of the hypothalamic-pituitary-adrenal (HPA) system. There is a statistically significant correlation between cortisol concentrations in saliva and plasma (Vincent & Michell 1992).

The leader of the training center was interested in investigating solutions to reduce the stress on dogs during training with two considerations in mind; the well-being of the dogs and their owners, and the improvement of the performance of these highly valuable dog-human-teams,. The Ministry of Internal Affairs approved and financed an experimental study with dog appeasing pheromone. The purpose of this study was to evaluate the effects of the dog appeasing pheromone in a new galenic form –  as DAP® collar –  on stress symptoms during the basic training course.

The hypothesis of the study is that dogs with the DAP® collar will show less stress symptoms than dogs with the placebo. 

Materials and methods

This is a double-blind placebo-controlled study which ran over a period of 4 weeks.

Nine male dogs (2 German Shepherds, 4 Malinois, 2 Dutch Herder and 1 Giant Schnauzer)  that were between 19 and 22 months (mean value 21 months) in the training course were divided into 2 groups (randomized by age, breed, province). Five dogs received a DAP® collar (CEVA France) and 4 dogs received a placebo collar at the beginning of the course. The dogs wore the collars all the time during the test period. To eliminate an influence from dogs with a DAP collar on the placebo dogs during the daily car rides, only dogs from the same group could be together in a car. The dogs were also living in adjacent kennels together with their group, with a free kennel in between the 2 groups.

During the night, the dogs were confined in the closed indoor part of the kennel between 9 p.m. and 5 a.m. The outdoor part of the kennel was opened at 5:00 in the morning by the trainer. The trainers and the owners lived in another part of the house and could hear their dogs when vocalizing at night. The dogs were fed between 6:30 a.m. and 7:30 a.m. At 8 a.m, they were transported by car to the various training environments. The working day ended at 4 p.m. and the owners were free to care for their dog individually - massage, play, relax, walk in the forest, etc. On the week-ends, owners and dogs were at home with their families.

None of the usually used anti barking collars were allowed.

The placebo collars were regular DAP collars, but with the components of DAP destroyed. The original packages were opened and the collars exposed to warm temperatures (sun and heater) and moved daily for more than 4 weeks (the producer gives up to 4 weeks as the time for effective use on the dog). After this period the collars were laid for 1 hour in hot water (approximately 70-80°C) and for 30 minutes in 70% alcohol to completely remove and destroy the components of the DAP. The DAP collars were opened only the day before the course. After this procedure there was no visible external difference between the placebo and the DAP collars except for a group identification symbol drawn on the clip.

Before the training course, the dog owners were informed about the purpose of the experiment and received handouts with instructions and a short presentation about signs of stress, as well as the basic rules for greeting and leaving the dogs.

Every dog was physically examined and weighed at the beginning and the end of the study.

Saliva samples for cortisol tests were collected by letting the dog chew on cotton balls (Salivette®, Sarstedt). The first samples were taken at home the day before the arrival at the training center. The following saliva samples were collected on the first day of each week in the early morning (evaluation of stress during the first separation/night each week); and, in the afternoon of the same day, immediately after training (evaluation of training stress). The saliva samples were frozen in a household freezer. At the end of the study, the concentrations of saliva cortisol were measured by a radioimmunoassay at the Department for Natural Sciences/Biochemistry, University for Veterinary Medicine in Vienna.

Physical and behavioral signs such as appetite, salivation, diarrhea, panting, destructiveness, vocalization at night and the psychological condition (relaxed, excited, exhausted, concentration at work) were determined on a daily basis by the owner. The learning capacity and performance at work as well as vocalizing at night and the condition after opening the indoor kennel in the morning were determined independently on a daily basis by the trainer.

Data analyses were made with the Mann-Whitney test, the Wilcoxon and the Fisher-Yates test, using a software program (SPSS, version 9.0.1).


From the first training day on, all dogs were quiet during the night. This was interesting and not expected. Only one dog of each group barked during the 4 weeks and this was for a few times and for less than 10 minutes. Usually, when one of these highly reactive dogs starts barking at night, several other dogs will follow and there is increasing excitement and vocalization for a long time. In this training course, surprisingly and for the first time in years, no dog reacted to the vocalization of another dog.

In the morning, the dogs were relaxed and sometimes came out yawning and stretching, obviously aroused directly from sleep, out of the indoor kennel. Only one dog from the placebo group panted excitedly on several mornings and one time another dog from the placebo group destroyed his plastic basket.

There were no dogs with diarrhea, salivation or appetite loss.

The weight of the dogs in the DAP collar group remained stable; the dogs in the placebo group lost weight. Even though p = 0.069 is just slightly above the significant value, this result should be considered an important fact and a sign of a possible chronic stress.

The difference in the values in morning saliva cortisol between the DAP and the placebo group was statistically significant in the second week of the training course (p = 0.016). The performance and the psychological condition of all dogs were very good according to the owners and the trainer. Every dog was successful in the tests at the end of the training period and was accepted for police service.


Results of the present preliminary study suggest that, compared with a placebo collar, DAP collars significantly reduce stress symptoms in dogs that are triggered by social separation and intensive training in a novel environment. The atmosphere during the whole training course was relaxed and respectful. Knowing that the dogs felt better in the kennel and performed well during the working day had obvious effects on the well-being of the humans – owners as well as trainers – too.
Of course, the sample group size of nine dogs is not large enough to establish a continuous level of significance. The behavior of this group of dogs was a bit unusual because little of the stress behavior previously reported in these training conditions was seen here.


We can conclude that the DAP collar, in combination with education of the owners is effective to reduce stress symptoms in young adult police dogs during their crucial training course.
From a systemic and clinical point of view the subjective satisfaction and well-being of the owners and trainers is very important for a sympathetic attitude when teaching their dogs.
These data should be viewed as an adequate basis for further studies.   


Beerda B, Schilder M B H, et al 1997 Behavioural, saliva cortisol and heart rate responses to different types of stimuli in dogs. Applied Animal Behaviour Science 58: 365-381.
Tuber D S, Hennessy M B, Sanders S, Miller J A 1996 Behavioral and Glucocorticoid Responses of Adult Domestic Dogs (Canis familiaris) to Companionship and Social Separation. Journal of Comparative Psychology, 110 (1): 103-108.
Vincent I C, Michell A R 1992 Comparison of cortisol concentrations in saliva and plasma of dogs. Research in Veterinary Medicine, 53: 342-345.

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