STUDI SULL'UTILIZZO DEI COLLARI D'ADDESTRAMENTO (in inglese)
Scientific studies
[edit]Christiansen et al study (2001a)
Christiansen et al, looked at behavioural differences between three breeds of dogs when confronted by domestic sheep (138 dogs; Elkhounds, hare hunting dogs and English setters). Two testing procedures were used and shock collars were used to deter attacks on sheep. The first, a path test, involved observing the dogs' reactions to a set of novel stimuli (rag pulled across the track, bundle of cans thrown down, tethered sheep at 5m) as it was walked. The second test involved monitoring the dog's reaction to a free-roaming sheep flock in a field. In this study they identified several factors that predicted a high hunting motivation and attack severity. These were lack of previous opportunity to chase sheep, low fearfulness towards gunshots and unfamiliar people and general interest in sheep when encountering them. Younger dogs (<3 years of age) showed more pronounced initial hunting motivation and more frequent attacks. Elkhounds showed more hunting behaviour, more attacks and were more frequently given electric shocks during the tests. A shock collar was used to deter attacks on the sheep during the experiments. Shocks (3000V, 0.4A, duration 1 second) were delivered when dogs came within a distance of 1-2m of the sheep, and were repeated until the dogs left the area. The objective was to suppress an attack, but not to damage the hunting ability of the dogs. Despite frequently initiated chases and attacks, few shocks were delivered. This was because few dogs approached closer than 1–2 m, and the intention was to deter proximity to sheep rather than to associate hunting behaviour with an aversive shock, which would impair future hunting behaviour in other contexts.
[edit]Christiansen et al study (2001b)
The dogs used in the first study were re-tested using the same procedures in order to assess the long term impact of the training on their reaction to sheep. Again, in the free-running tests the dogs were fitted with a shock collar, which was used to deter approaches to within 1-2m of the sheep. Dogs that had previously been shocked in year 1 showed a significant increased in latency to approach a person during the path test (p<0.001), even though this was not a condition under which shocks had been delivered. Owners reported behavioral differences between year 1 and 2 in 24 of the dogs. 18 of the 24 dogs had shown no interest in sheep during that period, even though they had been interested in them during the first year tests. However, only one of those dogs had received shocks, so the change in behaviour could not be attributed to the use of the shock collar. When comparing owners’ reports for the two years, the dogs showed a weaker inclination for chasing sheep and other prey than previously (p < 0:001), but this variable was not affected by shock experience. Dogs that had shown interest in sheep in year 1 showed a persistent interest in year 2. No dogs chased or attacked sheep as their first response, while half of them did so the first year. During the entire test period, the proportion of dogs attacking sheep was reduced to almost one fourth. The number of shocks administered per dog was reduced by the second year, and only one of the dogs which received el. shocks the first year needed el. shocks also the second year.The observations that both receivers and non-receivers of el. shocks the first year showed a reduction in the probability of chasing sheep, but the receivers showing a larger reduction, show that el. shock treatment provides an additional learning response. No adverse effects on the dogs were observed with this training procedure, but in their discussion the authors commented "In order to ensure no negative effects, we recommend that the electronic dog collar may be used for such purposes only if it is used by skilled trainers with special competence on dog behaviour, learning mechanisms, and of this particular device."
[edit]Polsky study (2000)
Polsky presented a set of five case reports based on data from legal documents relating to personal injury lawsuits involving severe attacks on humans by dogs who were being trained or maintained on an electronic pet containment system (using a shock collar). In every incident, the dog was within the "shock zone" and all fences were working; the dogs must then have received a shock. Four of the five dogs were not subject to threatening behavior by the victims prior to the attack. None of the dogs gave any kind of warning prior to biting, and all bit their victims repeatedly and seriously in the head, face, back and neck.
The analysis suggests that the dogs' aggression was caused by the shock. There are several unknown factors to the cases, including the training used to introduce the dog to the fence, the amount of time the dog spent outside unsupervised, and what level of shock intensity the dogs received. However, the reaction of the dogs, and especially the severity of the attacks, was inconsistent with their past behavior. Polsky concluded a "possible interpretation in terms of unconditioned aggression as a result of a dog having received electronic shock and avoidance-motivated aggression mediated through fear reduction toward human stimuli."
[edit]Salgirli dissertation (2008)
The aim of Salgirli's study was "...to investigate whether any stress is caused by the use of specific conditioned signal, quitting signal, and/or pinch collars as alternatives to electric training collars, and if they do so, whether the stress produced in the process is comparable to the one with electric training collars." The study population were a group of 42 adult police dogs. The quitting signal was a conditioned frustration equivalent to negative punishment. It was conditioned by associating failure to obtain an anticipated food reward with a specific vocal signal. In the test, dogs were walked passed a "provocateur" who attempted to taunt the dog into a reaction. If the dog reacted it was punished, and if it failed to react on subsequent provocations then the punishment was deemed to have had a learning effect. The study is therefore a comparison of negative and positive punishment methods, and not a comparison of punishment with positive reinforcement. Learning effect was measured by assessing the number of dogs that learned to quit a behaviour after application of the punishing stimulus. There was no statistical difference in learning effect between the pinch and shock collar, but the quitting signal produced a significantly poorer learning effect compared to shock or pinch collars (p<0.01 in both cases). "Although the pinch collar caused more behavioral reactions, in the form of distress, than the electronic training collar, the electronic training collar elicits more vocal reactions in dogs than the pinch collars"; the explanation for increased vocalisation in the shock collar group was that this was due to a startle response rather than pain reactions.
Salivary cortisol was monitored to measure the stress levels of the dogs, but this data was not presented in the dissertation; behavioral observation was the sole measure of stress. The study concluded that the electronic training collar induces less distress and shows stronger “learning effect” in dogs in comparison to the pinch collar. Commenting on the quitting signal, the author stated "It should particularly be mentioned, that the quitting signal training was implied only on adult dogs within the frame of this study. Therefore, the results should not be interpreted as that the quitting signal can not be a suitable method in police dog training. As previously stated training of the quitting signal requires a hard and a structured procedure. Thus, if the training, namely the conditioning, begins in puppyhood, the quitting signal can also be an effective method in police dog training". Comparing the effects of the three punishment methods; "These results can probably be explained by that electronic training collar complies completely with the punishment criteria, which were defined by TORTORA (1982), in case of proof of the proficient and experienced user. On the other hand when applying the pinch collar, these criteria can not be met even though perfect timing is applied since reactions of the dog and effectiveness of the method depends on several different factors such as the willingness, strength and motivation of the handler, as well as his/her proficiency. In addition to that, the visibility of the administrator and, thus, of the punishment is another important factor influencing the efficiency of the pinch collar because the dog directly links the punishment with its owner. Therefore this method does not satisfy the ‘’punishment criteria’’ at all. The quitting signal on the other hand requires criteria, such as good timing and structured training procedure, on account of complete conditioning in order to achieve effective results. Even if these criteria are met, the personality trait of the dog is another factor, which influences the efficiency of the signal."
[edit]Schalke et al. study (2007)
Schalke et al. conducted a 7-month study to investigate the effect of shock collars on stress parameters, in a series of different training situations. Heart rate and saliva cortisol were used to determine the stress levels in three groups of dogs. Group A received the electric shock when they touched the "prey" (a rabbit dummy attached to a motion device), Group H ("here" command) received the electric shock when they did not obey a previously trained recall command during hunting, and Group R (random) received random shocks that were unpredictable and out of context. Group A did not show a significant rise in cortisol levels; the other two groups (R & H) did show a significant rise, with group R showing the highest level of cortisol. Salivary cortisol was measured, as this procedure is less likely to cause stress related rise in cortisol.
From this the researchers concluded that the dogs who could clearly associate the shock with their action (i.e. touching the prey) and as a result were able to predict and control whether they received a shock, did not show considerable or persistent stress. The evidence of increased stress in the other groups was felt to support earlier findings that poor timing and/or inappropriate use of a shock collar puts the dog at high risk of severe and ongoing stress. They conclude that "The results of this study suggest that poor timing in the application of high level electric pulses, such as those used in this study, means there is a high risk that dogs will show severe and persistent stress symptoms. We recommend that the use of these devices should be restricted with proof of theoretical and practical qualification required and then the use of these devices should only be allowed in strictly specified situations."
[edit]Schilder & van der Borg study (2004)
Schilder and van der Borg conducted a study to compare the behavior of police service dogs that had previously been trained using a shock collar (Group S) with those which had not (Group C). In the training test no shocks were applied, but the animal's behavior was observed during training tasks. The intention was to investigate whether shock collar based training might have a long term effect on stress-related behavior even in the absence of shock, and whether this related to specific features of the training context. Behaviors recorded included recognised indicators of stress (panting, lip-licking, yawning, paw lifting and body posture) as well as yelping, squealing, snapping and avoidance. During free walks on the training grounds, groups S dogs showed significantly more stress related behaviors and a lower body posture than group C dogs. During training, the same differences were found. The difference between the groups was more significant when training took place on the familiar training ground, indicating a contextual effect. The presence of the trainer was considered to be part of this context. The authors concluded "We concluded that shocks received during training are not only unpleasant but also painful and frightening."
Lindsay says of this study, "Schilder and Van der Borg (2004) have published a report of disturbing findings regarding the short-term and long- term effects of shock used in the context of working dogs that is destined to become a source of significant controversy.... The absence of reduced drive or behavioral suppression with respect to critical activities associated with shock (e.g., bite work) makes one skeptical about the lasting adverse effects the authors claim to document. Although they offer no substantive evidence of trauma or harm to dogs, they provide loads of speculation, anecdotes, insinuations of gender and educational inadequacies, and derogatory comments regarding the motivation and competence of IPO trainers in its place."
[edit]Steiss et al. study (2007)
Steiss, et al, conducted a four-week study of adult shelter dogs’ physiological and behavioral responses to bark control collars. Plasma cortisol was used as the stress measure. Dogs were randomly assigned to either a shock collar, a spray collar, or a dummy collar (control group). Dogs that were known to bark at an unfamiliar dog were used for the study. Test conditions involved presentation of an unfamiliar dog. Dogs wore activated collars for period of 30 minutes per day for three days in two consecutive weeks. The amount of barking was significantly reduced starting on the second day with both the spray and shock collars. There was no significant difference in effect between the two collar types. The treatment group dogs showed a mild yet statistically significant increase in blood cortisol level (an indicator of stress) only on the first day of wearing the collars (as compared to the Control Group.) At the conclusion of the study, Dr. Steiss and her team concluded that "In the present study, with dogs wearing bark control collars intermittently over a 2-week period, the collars effectively deterred barking without statistically significant elevations in plasma cortisol, compared to controls, at any of the time points measured."
[edit]Tortora Study (1983)
Tortora applied a method called "safety training" to treat aggression in 36 cases exhibiting a form of "instrumental aggression", selected after screening a population of 476 cases. "Instrumental aggression" was defined as describing aggressive acts that "do not have a clear evolutionary significance, are not directly related to emotional arousal, do not have specific releasing stimuli, are not directly modulated by hormones, and do not have an identifiable focus in the brain". Tortora states that in the context of the article "instrumental aggression" was specifically defined as "aggressive responses that have "a specifiable learning history, show a growth function over time and are modulated by their consequences. These dogs had few operant alternatives to gain reinforcement by compliance and were channeled down a path that allowed their innate aggressiveness to come under the control of the negatively reinforcing contingencies in the environment". The dogs initially behaved as though they "expected" aversive events and that the only way to prevent these events was through aggression. The dogs were therefore a highly selected subset that had not learned strategies for coping with threat.
Each dog was trained to respond to a set of 15 commands taken from the AKC standard for CDX obedience. The commands were selected to provide control over the dog , and included "heel", "stand" "go", "come", "hold", "drop" and "sit". These behaviors were termed "safety behaviors". Training was divided into 9 stages, each of which was composed of 5-20 twice daily training sessions. Dogs could only progress to the next stage after passing a test. On average, dogs took 10-15 sessions to complete each stage. After training basic commands, the dogs were trained to perform the behaviors they had already learned in order to avoid progressively increasing electric shock. After that, they were conditioned to perform a safety behavior in order to avoid a "safety tone" that allowed them to anticipate the shock. In the later stages of training, dogs were exposed to provocation by a distractor dog, and were punished using full intensity shock if they failed to perform a safety behavior or if they showed aggression. After training was complete, and the dog's were choosing to perform the safety behaviors instead of aggression, owners were taught to use the shock collar and the training was transferred into everyday situations. The training resulted in a long-lasting and complete suppression of aggressive behaviour in the dogs. Dogs were followed up 3 years after the end of training, and the reduction in aggression were maintained.
