Previous research has suggested that owners’ attitude to their family dogs may contribute to a variety of behaviour problems in the dog, and authors assume that dogs with separation-related disorder (SRD) attach differently to the owner than typical dogs do. Our previous research suggested that these dogs may have an insecure attachment style. In the present study we have investigated whether owners’ attachment style, personality traits and the personality of the dog influence the occurrence of SRD in the dog. In an internet-based survey 1508 (1185 German and 323 Hungarian) dog-owners filled in five questionnaires: Demographic questions, Separation Behaviour Questionnaire (to determine SRD), Human and Dog Big Five Inventory and Adult Attachment Scale. We found that with owners’ higher score on attachment avoidance the occurrence of SRD in the dog increases. Dogs scoring higher on the neuroticism scale were more prone to develop SRD. Our results suggest that owners’ attachment avoidance may facilitate the development of SRD in dogs. We assume that avoidant owners are less responsive to the dog’s needs and do not provide a secure base for the dog when needed. As a result dogs form an insecure attachment and may develop SRD. However, there may be alternative explanations of our findings that we also discuss.

Funding: This work was supported by the EU FP7 ICT-215554 LIREC ( http://lirec.eu/ ) and the Hungarian Academy of Sciences (MTA 01 031) ( http://mta.hu/ ). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Copyright: © 2015 Konok et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Introduction

Dogs and humans have been living together for tens of thousands of years and during this time domestication might have predisposed dogs to form attachment relationships with humans [1]. Dog puppies are typically acquired by human families at age between 6 and 10 weeks and the human owner becomes readily the primary attachment figure for the puppy [2]. Dogs show functionally analogue behaviours to human infants in the Strange Situation Test [3–5], that is, they seek the proximity of the owner and show stress-response during separation from him/her. The proximity of the owner serves as a secure base for the dog for exploring the environment [4–7] and a safe haven in threatening situations [8] similarly as parents’ proximity is for infants.

Humans also have a disposition to form an attachment relationship with their dogs [9] which might be facilitated by dogs’ paedomorphic morphological and behavioural features [10]. Kubinyi at al. [11] found that 93.3% of the owners considered their dogs as family members. Actually, using the Repertory Grid [12] technique Berryman [13] found that pet owners (mostly dogs and cats) see their pets significantly more like „own child” than any other family member. In addition, owners use their dogs as a safe haven (to alleviate stress) [9] more than any other family members or friends, except for romantic partners [14].

Separation stress and related disorders Stress response to separation is adaptive both in animals and humans. According to Bowlby [15] the ultimate function of parent–offspring attachment is to protect against predators and maintain the supply of resources for offspring if they remain in proximity to the parent(s). However, typical maturation results in increased tolerance of separation. In human children, separation anxiety [16] become problematic and is diagnosed as a separation anxiety disorder if it exceeds (in intensity and in age) normative reactions to separations from caregivers and cause troubles in social functioning [17]. Separation anxiety disorder is marked by recurrent excessive distress when separated from the home or important others, permanent and excessive worry about losing the attachment figures, refusal of going to school or reluctance to going to sleep alone [17,18]. A functionally analogue behaviour problem exists in dogs, which is referred to as separation-related disorder (SRD) [19]. This phenomenon occurs in the owner’s absence or when the dog is prevented access to the owner. Owners of dogs with SRD complain most frequently about destructive behaviour displayed at home, excessive vocalization (often noticed by neighbours), or inappropriate elimination (urination/defecation, e.g. [20]). Further symptoms (which are less easily recognized) include autonomic signs such as hypersalivation or hyperventilation, increased and repetitive motor activity (e.g. pacing, circling), repetitive behaviour (e.g. over-grooming or self-mutilation), behavioural signs of depression such as withdrawal, inactivity or inappetence, gastrointestinal symptoms (vomiting, diarrhea) or escape behaviour that can result in self-trauma [20–22]. Thus, it seems that both in humans and dogs there are individuals who have lower threshold for the activation of the attachment system [15], and who show a separation response that is developmentally inadequate, has extreme degree, form and consequences.

Attachment, caregiving behaviour and separation anxiety Attachment and separation anxiety are related concepts. According to Bowlby [15], securely attached children have the confidence that the attachment figure will be available and accessible if needed, thus they are less anxious during separation. In order for the child to feel accessibility and availability the mother (parent) has to be sensitive and responsive to the child’s needs (e.g. responsive to the infants' cries, sensitive in initiating and terminating feeding, etc.). Sensitive and responsive parenting consists of synchrony, mutuality, emotional support, positive attitude and stimulation [23]. In parallel with the theoretical assumptions, researchers found that insecurely attached children are more prone to show separation anxiety than securely attached children [24,25]. Children’s attachment style and separation anxiety is associated with parents’ caregiving behaviour [26–28]. Specifically, maternal responsiveness/sensitivity seems to be the primary predictor of a child’s secure attachment [29–33] and separation anxiety [25]. Parents’ caregiving behaviour is influenced by their own attachment style („adult attachment”, [34]). Van Ijzendoorn [35] hypothesized that the parents’ representation of past and present attachment experiences (Bowlby’s “inner working model”, [15]) influences the degree of sensitivity and responsiveness with which the parent reacts to the child’s attachment signals. These hypotheses were supported by investigations showing that insecurely attached adults show less consistent responsiveness to their children’s needs (for a meta-analysis, see [35]). More precisely, avoidant/dismissing mothers are the ones who are less sensitive/ responsive than secure mothers, and this is especially true in stressful situations or with mothers experiencing more psychological distress [36,37]. It seems that preoccupied (anxious) mothers have deficiency not in sensitivity but rather in autonomy support/non-intrusiveness [36,38]. As attachment styles are associated with different personality traits [39,40], and personality affects parenting [41], mothers’ personality can also affect the child’s attachment style and behaviour problems [42]. In summary, higher extraversion, agreeableness, conscientiousness and lower neuroticism seem to be associated with more secure adult attachment ([39,40], or for a meta-analytic review see [43]) and a warmer and more sensitive parenting (e.g. [41,42], or a meta-analysis: [44]). Thus these traits are plausible candidates for influencing children’s attachment style and behaviour problems including separation anxiety. However, as far as we know, no study has been carried out on the association between parental personality and the child’s separation anxiety.

The etiology of SRD in dogs: owners’ attitude, dogs’ attachment As SRD is much less studied in family dogs, we have only few data on the etiology of the disorder. The potential causes mentioned in the literature include pathologic “over-attachment” or “hyper-attachment” to the owner (e.g. [20]), negative early experiences such as too early separation from the bitch, other traumatic experiences while left alone, change in family circumstances (for details see [45]) or heritable factors [46]. McCrave [47] reported an increased prevalence of SRD in mixed breed dogs. However, mixed breed dogs are represented in a large percentage among shelter dogs [48] and staying in a shelter can contribute to the development of SRD [47,49]. SRD is reported more often in male dogs than in females [50–52]. Mendl et al. [53] reported that dogs from the shelter with SRD show more „pessimistic” choice behaviour in a food search test. In a previous study [50] we showed that dogs with SRD do not use the owner as a secure base. These dogs are very distressed upon separation and they cannot be easily calmed down by the return of the owner. During separation, they do not use an object substitution of the owner for self-reassurance, as typical dogs do. Thus, we assume that SRD dogs living in human families have an insecure attachment style, analogue to human C type (insecure, ambivalent/anxious) [54]. Note that this view is in contrast with the popular theory which holds that SRD dogs are “hyper-attached” to the owner. Two studies [50,55] reported that SRD dogs do not show more affection toward the owner (expressed by e.g. proximity to and body contact with the owner, eye-contact with the owner, fast tail-wagging) which contradicts the “hyper-attachment” theory. Based on the functional analogy in attachment between dogs and children we assume that owners’ responsiveness and sensitivity to the dog’s needs influences the dog’s attachment style and separation-related disorder as in the case of human mother-child dyads. Experts in behavioural disorders agree that owners’ attitude to the dog may contribute to a variety of behaviour problems [56]. For example, time spent with the dog and shared activities with the owner correlates negatively with dogs’ behaviour problems (e.g. disobedience, aggression, nervousness, overexcitement, etc.) [57,58]. Owners’ anthropomorphic emotional involvement correlates with the dog’s aggression toward people [56]. Owners’ personality was also found to be associated with dogs’ behaviour problems: Owners of aggressive dogs were reported to be emotionally less stable, more disciplined and tense than owners of non-aggressive dogs [59]. Owners’ neuroticism was found to correlate with the degree of the dog’s displacement activities [56] and with dogs’ neuroticism [60]. However, only one study observed an indirect association of owners’ attitudes and the dog’s SRD: the prevalence of separation- related elimination is lower if the dog has been subjected to obedience training and if it does not sleep in the bedroom of the owner [61].