Effects of Electrical Stimuli

Many studies were conducted to examine the physiological, physical and behavioral effects of electric shock in animals and, also, in humans.

2.4.2.1 Physiological and Physical Effects of Electrical Stimuli

In a study conducted by BEERDA (1997), the dogs were exposed to different types of stimuli such as sound blasts, electric shock, opening of an umbrella, restraintment and falling bag and subsequently their behavioral, saliva cortisol and heart rate responses were measured. The result of that study demonstrated that the unanticipated stimuli, i.e. electric shock, loud noise and falling back, induced increased cortisol responses, whereas the stimuli which were administered by the visible experimenter did not change the cortisol values in dogs.

In that study, heart rates were not measured when the effects of electrical stimuli were tested.

However, another research which examined the effects of human contact on the dog showed that increased heart rate was also observed in dogs when a tone was followed by electrical stimuli (LYNCH and McCARTHY 1969).

Already in 1983 DESS et al. demonstrated that an electric shock induced the elevation of adrenal cortisol and, also, that the uncontrollable shocks caused significantly higher cortisol response than the controllable shocks. In contrast to BEERDA’s (1997) findings, DESS et al.

(1983) stated that ‘’predictability’’ had no significant effect on cortisol responses.

A recent study conducted by SCHALKE et al. (2006), however, showed the important role of

‘’ predictability’’ in aversive dog training, such as electronic dog training. For this study, three experimental groups of dogs were used, each of which received the shock in a different manner. Group A (Aversion) received the shock when the dog touched the prey, Group H (Here) received the shock when the dog did not obey previously trained ‘’here’’ command and Group R (Random) received the shock randomly-out of context.

As a result, elevation of saliva cortisol level was significantly higher in group H and in group R when comparing with group A. Considering those results, SCHALKE et al. (2006) concluded that: ‘’animals, which were able to clearly associate the electric shock with their action - touching the prey - and consequently predict and control the stressor, did not show consistent and persistent stress indicators’’.

They also emphasized that there is a high risk that dogs will show persistent and severe stress symptoms in case of poor timing in application of high electric pulses. Overall, this study also pointed out the significance of predictability and controllability of the electric shock in dog training and further of good timing, namely of experienced trainers in administration of electronic training collars.

In a research performed on rats, it was found that during the acquisition and expression of the conditioned aversive stimulus - sound accompanied by electric shock-, modification of the synaptic projections from the auditory cortex of the brain to the lateral amygdala revealed (TSVETKOV et al. 2002). Thus, the changes in the brain during fear conditioned learning were emphasized.

POLSKY (1994) stated that inappropriate use of electronic training collars -extreme tight or long application - may cause lesions on the dog’s neck. He further emphasized that the lesions caused by mechanical abrasion result from the electrodes rubbing the skin rather than from the electric shock.

LINDSAY (2005) pointed out that the electric stimulus used in dog training causes no physical damage, neither to the skin nor to the underlying tissue. The introduction of electric stimulus, however, causes an illusion of startling stimulus by activating mechanic receptors along Aβ and Aδ fibers. As a result, transmitting of Aδ fibers cause ‘tingling’, ‘tapping’ and

‘fluttering’ sensations, whereas the transmitting of Aβ fibers cause sensation ‘pricking’. High levels of electric stimulus, on the other hand, may activate C-fiber which produces sensation of ‘burning’ (SANG et al. 2003). In other words, although no physical damage occurred, sensation of burning was perceived upon the administration of the high level of electrical stimulus.

2.4.2.2 Behavioral Effects of Electrical Stimuli

In the above mentioned experiment conducted by BEERDA (1997), it was also found that unanticipated stimuli such as electric shock elicited a very low posture correspondent to the increased saliva levels in dogs. The findings from the study carried on by SCHILDER and

In this study, direct reaction of dogs to electrical stimuli, as well as the comparison of the dogs trained with and without electronic training collars was investigated. As a result, it was found that the dogs showed the following reactions to the electrical stimuli: lowered body posture, high pitched yelping, barking, squealing, avoidance, redirected aggression and tongue flicking. Furthermore, the dogs trained with the electronic training collars exhibited lowered ear positions than the dogs trained without electronic training collar - but still in a harsher way.

All in all, SCHILDER and van der BORG (2004) concluded that receiving electric shock is painful for dogs and further that the dogs associate the owner’s presence with the receiving of the shock. Thus, they suggested banning these instruments from the dogs sports completely.

However, in a scientific review written by JACQUES and MYERS (2007), it was pointed out that since in the study conducted by SCHILDER and van der BORG (2004), no information was provided about the experience of the handlers and dogs and also about the level of shock,

‘’the study has come under considerable fire’’.

CHRISTIANSEN et al. (2001a) explained the reactions of the dogs to the electric shock as following: ‘’displaying grades of jumping, head shaking, vocalizations, and the speed of withdrawal from the sheep’’. They further pointed out that these reactions differed between individuals. Additionally, in this study, the significance of timing in electronic dog training was indicated and it was also suggested ‘’to avoid this method for other purposes than training dogs to avoid chasing sheep.’’

CHRISTIANSEN et al. (2001b) presented a subsequent study examining learning effects of the electronic dog collar in the following year. Considering their findings in that study, they cited that the use of electronic training collars is an efficient way to prevent the undesirable hunting behavior in dogs. They also indicated that no adverse effect of this method was observed.

In a study conducted by POLSKY (2000), it was found that unconditioned aggression can be evoked as a result of a dog having received electric shock. REISNER (2003) also cited that human directed aggression might be observed upon the administration of aversive methods such as electric stimulation, prong or training (choke) collars as a result of increase anxiety.