From Puppy Love to Pet Peeve: What Causes Second/Successor Dog Syndrome in Assistance-Dog Handlers and Companion-Dog Owners?

ABSTRACT In a Guide Dog population, there is a higher return rate of handlers’ second dog compared with any prior or subsequent dog pairings. This phenomenon is called Second Dog Syndrome (SDS). Qualitative studies have identified defining features of this syndrome in Guide Dog handlers; however, there has been no peer-reviewed study into the experience of SDS in companion-dog owners or handlers of other assistance dogs. As such, this exploratory study aimed to define the SDS experience in companion-dog owners and assistance-dog handlers. Ten participants, all women, were recruited to participate in focus groups for companion-dog owners (n = 5) and assistance-dog handlers (n = 5). Transcripts were analyzed using thematic analysis. SDS was characterized by a strong bond with the previous dog, ongoing bereavement related to the previous dog loss, negative emotions related to the successor dog, and inability to bond with them. This appeared to be due to comparisons made between the successor and previous dog and unmet expectations of the new dog. For companion-dog owners it was also characterized by a fear of getting hurt again; for assistance-dog owners it was an inability to trust the successor dog, differences in work ability, and a threat to their independence. Time since the loss of the previous dog, awareness of the phenomenon of SDS, and support from the community also influenced the SDS experience. One unexpected finding was that SDS was not exclusively linked to second-paired dogs and that it may be more aptly named “Successor Dog Syndrome.” Given that poor outcomes associated with unsuccessful dog–owner bonding may result in relinquishment, this study provides an important first step to being able to quantify the experience of SDS to develop interventions in the future.

Dogs play important roles in society.In Australia alone, it is estimated that 38% of households include a companion dog (Pet Industry Association, 2018), with most owners viewing them as part of the family (McConnell et al., 2016).Dogs are also used in many forms of assistance, including guiding, hearing, providing mobility support, providing psychiatric support, and detecting and responding to medical issues such as diabetes and epilepsy (Bremhorst et al., 2018).Given the reported depth of human-animal bonds (for a review see, Zilcha-Mano et al., 2011) it is unsurprising that losing a companion animal or assistance animal can elicit a similar grief response to the loss of a close human relationship (Gerwolls & Labott, 1994).In one study, for individuals who retrospectively self-reported a more anxious style of attachment (Bowlby, 1958) toward their late pet, the impact of pet loss was positively associated with both complicated grief and trauma symptoms (Brown & Symons, 2016).In this population, distress often arises because of a continuous failure to re-establish a connection with the deceased dog, leading to profound feelings of hopelessness and despair (Field et al., 2009).It has been reported to affect approximately 30% of pet owners (Adams et al., 2000).Tzivian et al. (2014) found that in multiple companion-dog homes additional pets appear to assist owners during the bereavement process, and owners of multiple companion dogs are more open to the possibility of acquiring a new pet.Conversely, for others, the mere suggestion of replacing the deceased pet is comparable to the inappropriateness of urging a new widow to find another spouse as these individuals may require additional time to mourn and accept the loss of their beloved companion (Packman et al., 2011;Packman et al., 2012).Cordaro (2012) puts forward the need for resolution and acceptance over the death of a pet before accepting another.In this way, the new pet can be accepted without owner expectations that they will help resolve the grief experienced or replace the previous pet by perhaps possessing similar characteristics (Cordaro, 2012).
Being prepared to accept a new pet "as they are" is important because the acquisition of one can result in relinquishment if a meaningful bond between owner and pet cannot be established.Relinquishment by owners represents one of the most common forms of admission of companion dogs into shelters (Hemy et al., 2017).In the worst-case scenario, dogs admitted to animal shelters may be deemed inappropriate for adoption and are euthanized.Not only is this outcome unfavorable for the animals but it can also be an emotionally painful experience for the owner (Shore, 2005).Similarly, if an assistance dog is returned to the training provider because the handler does not bond with it, this represents a considerable waste of resources: it can cost up to USD $50,000 to raise and train an assistance dog (Guiding Eyes for the Blind, 2022).
Given that a large number of owners do not provide a rationale for the relinquishment of their companion dog to a shelter (DiGiacomo et al., 1998), there may be an unexamined factor that explains some of the variance in relinquishment rates.Looking to the assistance-dog population could provide insights on this.Schneider (2005) first published on the potential for unresolved grief over a previous dog to negatively impact the relationship with the successive dog, stating: "the more actively one lets oneself grieve, the less likely one is to take it out on the next dog in some second-dog syndrome comparison" (p.370).Lloyd et al. (2016) investigated the return rates of Guide Dogs and discovered that a higher return rate was associated with second paired dogs, as compared with first, third, or any subsequent pairing.Consequently, they named this phenomenon "Second Dog Syndrome" (SDS; Lloyd et al., 2016).In interview studies describing the challenges associated with transitioning from first to second dogs, handlers reported different facets such as expectations, grief, comparisons between first and second dogs, and unanticipated temperament (Ward & Peirce, 2010).
The limited research to date on this topic has focused exclusively on Guide Dogs, a subset of assistance dogs.Whether this phenomenon is also relevant to companion dogs is unclear because assistance-dog handlers experience a higher degree of interdependence with their dog than companion-dog owners (Kwong & Bartholomew, 2011).Currently, there is no research on whether SDS is experienced by companion-dog owners or handlers of assistance dogs other than Guide Dogs.Given the increase in the types of disability support offered by assistance dogs in recent years (e.g., autism, mobility, PTSD; Howell et al., 2016), it is important to investigate this phenomenon in other populations of assistance-dog handlers.As such, this exploratory, qualitative study investigated whether a similar account of SDS is reported by companion-dog owners and assistance-dog handlers, with the specific aim being to characterize the key features which define the syndrome in both populations.

Methods
Ethical approval was granted by Monash University and La Trobe University Human Research Ethics Committees (Project ID: 24490).

Participants
Participants were recruited by posting an online Facebook advertisement amongst the researchers' professional and personal networks.Owing to unanticipated difficulty in recruiting participants whose experience of SDS was associated with their second paired dog, and because several prospective participants experienced SDS with other successive dog pairings, the inclusion criteria were expanded to include those with successive dog pairings on a case-by-case basis.Thus, the final eligibility criteria for participation in the study were (a) 18 years or older, (b) fluent in English, (c) had lost a previous companion or assistance dog, and (d) were currently experiencing or had previously experienced self-reported SDS with a current dog.SDS was defined in the recruitment materials as "thoughts and feelings toward your second dog that are not necessarily positive or as strong as those toward your first dog."Participants were further excluded if their SDS experience related to a previous dog and not their current dog, or their experience had been more than five years ago.
Participation in the research was voluntary and no incentives were offered.The final sample included five female companion-dog owners and five female assistance-dog handlers.Females were not specifically targeted but proved more forthcoming in volunteering their participation.Additional participant characteristics are presented in Table 1.

Materials
Demographic information (see Table 1) was collected using an anonymous online survey accessed by a Qualtrics link sent via the chat function of Zoom before the focus-group discussions commenced.Qualitative data were then gathered via the asking of nine questions (see Table 2).

Procedure
Participants who consented to participate in the study were sent a link to join one of three 90-minute online focus groups conducted via Zoom.Focus-group session one was conducted with two companion-dog owners, whilst the second group had three companion-dog owners.The third focus group included all five assistance-dog handlers.Two researchers facilitated all three groups: one primarily facilitated the sessions, whilst the other took notes as a back-up in case any recordings were lost (none were).
During the sessions, participants first provided visual or verbal consent to record.Participants were then directed to complete the online demographic survey.For the remainder of the session, participants were asked to discuss the nine questions, which were provided verbally by the researchers as the session progressed.

Analysis
The focus-group recordings were transcribed manually by the research team and participants were identified using a pseudonym.The transcript was analyzed according to the six steps of a thematic analysis process described in Braun and Clarke (2006).This study used a hybrid approach, similar to Fereday and Muir-Cochrane (2006), which included both a deductive and inductive approach to theme development.The deductive orientation aided in identifying similar themes found in the experience of SDS in Guide Dog owners (Ward & Peirce, 2010), while the inductive approach permitted us to identify themes exclusive to the companion-dog owner population, or which were not represented in Ward and Peirce (2010).
Given the exploratory nature of the study, all participant responses were coded and translated into themes and subthemes.Author MD initially coded the companion-dog owner data, and TJH coded the assistance-dog handler data.Then, the companion-dog owner findings were assessed by TJH, and the assistance-dog handler data were assessed by MD to establish inter-coder reliability (Coolican, 2014).The preliminary codes were then subjected to in-depth discussions among all three authors to refine them until all authors agreed on the codes, themes, and subthemes, including consistent names for What adjectives would you use to describe how SDS feels? 4.
When a person has SDS, how do they feel towards their first dog?6.
When a person had SDS, how do they feel towards their second dog? 7.
Would you like to be able to bond with your second dog more? 8.
What would it mean if the bond you had with your second dog was equal to that of your first dog?9.
Anything else you'd like to add? SDS = second dog syndrome.
the companion-and assistance-dog groups, where relevant.To gain a breadth of data and ensure the research aim was addressed, no themes were excluded based on low participant endorsement.

Results and Discussion
The focus group thematic analysis identified a total of seven key features which define the experience of SDS for both companion-dog owners and assistance-dog handlers.One additional theme was reported by companion-dog owners exclusively, and there were three additional themes specific to assistance-dog handlers.All 11 themes are presented in Table 3.
The findings of this exploratory study suggest that SDS is experienced similarly by both companion-dog owners and assistance-dog handlers, with some unique defining features for each.As outlined in Table 3, three additional features specific to assistance dogs related to the dog's working role, and for participants in the companion-dog group, SDS was additionally characterized by a fear of feeling the same grief they felt for their previous dog again, which was not observed in our assistance-dog group.
Interestingly, the experience of SDS was not limited to the second paired dog for either assistance-dog handlers or companion-dog owners, and participants experienced features of SDS with other dog pairings.As such, we will continue our discussion using the term "successor dog syndrome" in place of "second dog syndrome." In addition to the key features which defined the experience of SDS (see Table 3), three other themes were discussed by the participants.These themes did not characterize the experience of SDS but seemed to influence the experience of SDS for the participants (see Table 4).

SDS Unpacked
One of the key features of SDS, which was endorsed by all participants, was the special connection they had with their previous dog (see Table 3, "Strong bond with previous dog"), reportedly influenced by the dog's unique personality characteristics and traits.Participants' loyalty to their previous dog may represent a means of preserving the relationship and high esteem they had for them, despite a somewhat contradictory, but unanimous, desire by all participants to create a bond with the new dog that is equal to the one they had with the previous dog (see Table 3, "Inability to bond with successor dog").It is interesting that, despite being unable to, participants did want to bond with their successor dog.We had presumed that the establishment of a new bond might make participants feel that this would somehow invalidate the uniqueness and special relationship they had with their previous dog.Indeed, this may be a preventative factor in people acquiring a successor dog, but in the case of the current sample, they had already acquired their dogs, so this may reflect a desire to "make it work."However, the loyalty the owner has toward the previous dog, even after its death or retirement, and the desire to preserve the bond's unique nature, are suggestive of a continuing bond.The literature on continuing bonds indicates that successful adaptation to bereavement requires reorganizing the relationship to the deceased animal (Packman et al., 2011) to an internal representation based on memories, meaning, and emotional connection (Podrazik et al., 2000) and relinquishing the goal of physical connection with the deceased pet (Field et al., 2005).The inability to relinquish physical connection " … once we did get along, I think he really opened up a lot to me.I was able to go out and do things alone which was a big difference."(Andrea.assistance-dog handler) Notes: Common features are ordered according to a theoretical chronological timeline.*Theme specific to companion-dog owners.**Theme specific to assistance-dog handlers.
and the continuing bond may be the rationale for why one of the participants considered cloning their deceased companion dog.For example, Rebecca reported: "I was looking into perhaps cloning him so that I could have another version of him."Sentiments like this suggest that the owners were not seeking another dog, but still seeking connection with the same dog.
Another key feature of SDS was profound grief associated with the death/retirement of the previous dog (see Table 3, "Ongoing bereavement related to previous dog loss").This was observed irrespective of how the dog loss occurred (e.g., if it was sudden/unexpected or protracted).Participants reported that unresolved grief and loyalty to maintaining the bond with the previous dog were additional factors which prevented them from bonding with their successor dog.The unresolved grief reported by participants may suggest they have not completely accepted the loss of their previous dog.As discussed in Cordaro (2012), acceptance is an important factor that allows pet owners to better care for their new pet.Several factors have been identified which may increase the severity of grief symptoms, including an anxious attachment orientation (Field et al., 2009) and owners who place more value on their pets than friends or relatives (Weisman, 1991).Some participants compared their relationship with their deceased pets to those with relatives or other typical human dyads: for example, Rebecca stated, "You don't see your aunts, your uncles, your cousins, none of them (…) those circumstances you do get a very strong bond which when it breaks is pretty tough."As discussed by Adams et al. (2000), 30% of companion-dog owners experience maladaptive grief or complicated grief.Given the expression of grief experienced by companion-dog owners and rates of complicated grief reported in studies such as Adams et al. (2000), SDS may manifest from complicated grief if a successor dog is acquired before this can be resolved (although it is worth noting that attachments styles were not measured in the current study).For pet owners and assistance-dog handlers, unsuccessful reorganization of the relationship with the deceased/retired pet, especially by anxiously attached individuals experiencing a persistent grief response, may cause them to continue to attempt to maintain the bond with the deceased/retired animal (Field et al., 2009).This appears to hinder them from bonding with their new dog and may therefore represent unsuccessful emotional reorganization and an unsuccessful adjustment after bereavement (Field et al., 2009).
Participants discussed whether the grief experienced by SDS was exacerbated due to a lack of social recognition by others in the community, which could cause the mourner to experience disenfranchised grief (Lavorgna & Hutton, 2019).This refers to a grief that is underappreciated and not fully recognized by society and is said to leave the griever without validation or social support (Packman et al., 2011).Participants expressed mixed responses, with several reporting that they received some support but also a lack of understanding regarding their grief (see Table 4 "Support").Given that anxious attachment to the deceased companion animal is related to symptoms of complicated grief (Brown & Symons, 2016), if disenfranchised, it may further exacerbate the experience of clinical or complicated grief for this cohort.Therefore, it may be worthwhile for future studies to consider the effect of disenfranchised grief and attachment orientation and whether this can heighten the experience of SDS.
When companion-dog owners described the profound grief they experienced after the loss of their previous dog, they reported that both; allowing time to grieve the loss of the previous dog, and time to develop the bond with the successor dog (see Table 4 "Time"), contributed to the experience of SDS.Each of the companion-dog owners, apart from one who had a period of dual dog ownership, reported having acquired their successor dog within six months after the death of their previous dog.Both participants in focus group 1 reported that if they had waited a longer time before acquiring their successor dog and allowed themselves more time to grieve the loss of their previous dog, this may have decreased their experience of SDS and improved their ability to bond with their successor dog.Studies such as Packman et al. (2011) indicate acute phases of grief occur within two months after the death of a pet, whilst complicated grief can last from six months to a year later, and subclinical levels can present for six months or longer.With the majority of the participants acquiring their successor dog within six months, and considering the time frames suggested in the study by Packman et al. (2011), this may once again indicate that participants with SDS were experiencing complicated grief which impacted the ability to bond with the successor dog.
Whilst no precise time frames have been provided within the literature regarding an appropriate length of time before acquiring a new companion dog after the loss of a previous dog, Cordaro (2012) provides some direction to owners by suggesting that they are only ready to care for a new companion animal once they have accepted the loss of their previous one.It appears participants in the current study may not have achieved this acceptance, with two reporting that they acquired their successor dogs as replacements to fill the void of their previous dogs.With companion dogs, it should be feasible to take as much time as required to grieve the loss of the previous dog before acquiring a new one.However, with assistance dogs, this may not be possible, especially if the handler needs a new dog to help them maintain their independence or safety.As such, SDS may be a more hard-to-manage problem in this population.
In addition to ongoing grief over the previous dog, SDS is characterized not only by difficulty bonding with the successor dog but also negative feelings toward the new dog and new dog ownership.The role of expectations might explain these findings.For example, as reported by Cordaro (2012), the inability to achieve acceptance of the previous dog's death may cause owners to be more inclined to assume the same characteristics of the previous dog in the successor dog and to expect that the successor dog will provide emotional relief from the grief experienced from the death of their previous dog.When these expectations are not met, this can hinder bonding with the successor dog, leading to a potentially inferior relationship with this dog.Expectations of the successor dog based on the previous dog, as well as comparisons between the successor and preceding dog appear to be important features defining the syndrome (see Table 3 "Unmet expectations placed on successor dog" and "Comparison between previous and successor dog").In the current study, all participants reported engaging in some form of comparison between their previous dog and successor dog; some were general comparisons, whereas others were more specific.Several participants recognized that comparing the dogs on certain traits may have been unfair, such as comparing the relationship and temperament of an older dog (i.e., their previous dog) with their current, younger, less mature dog.Overall, participants expressed that, despite their preceding dog also having undesirable behaviors, a defining feature of SDS was a lower tolerance toward their successor dog.
Similar findings of comparison presented as a critical feature of SDS in previous research with the Guide Dog population.Ward and Peirce (2010) explain that this comparison appears to act as a barrier that hinders the handlers from appreciating the positive qualities of their subsequent dog.It can also assert the successor dog as "second best" when they do not measure up to the qualities of the previous dog (Lloyd et al., 2016).Similarly, the results of this study suggest that handlers often made comparisons between their new, untrained young dog and their old dog, with whom they had had a long, successful partnership.Handlers seemingly forget the difficulties and challenges they experienced when they acquired their initial dog (Ward & Peirce, 2010).Taken together, comparisons made between their young dog with their previous dog at the end of a successful partnership can be detrimental to establishing the owner-animal bond in both companion and assistance animals.

SDS Features Unique to Specific Dog Groups
Three themes were specific to the assistance-dog handlers in this study, all of which relate to the dog's working role.These were: the dog's ability to enable the handler to become more independent, the dog's ability to effectively perform his/her working role, and the level of trust between the dog and handler (Table 3).Many studies have shown that assistance-dog handlers perceive that their dog increases their independence, and this appears to be a key benefit of having an assistance dog for many handlers (Gravrok et al., 2020;Howell et al., 2016;Howell et al., 2019).In the current study, the lack of trust in the dog, or an observed inability of the dog to perform the required working role, would necessarily impact the handler's level of independence.Therefore, it is understandable that lack of trust and concerns about the dog's working ability are relevant to assistance-dog handlers' SDS experience.Some of these dogs were provider-trained, while others were handler-trained.SDS has not previously been reported among handlertrained assistance-dog handlers, but this deserves further study, especially as one of the reported benefits of handler-trained assistance dogs, compared with providertrained dogs, is the ability of the dog and handler to establish a strong bond early in the dog's life (Howell et al., 2019;Sillaby, 2016).If the handler is experiencing SDS, this would necessarily impede the development of such a bond and could also mean that the handler is diverting resources toward raising and training a dog that will not ultimately become their assistance dog, if the bond can never fully develop.
Among companion-dog owners, the only unique theme was the fear of getting hurt again.Given that this fear appears to arise out of profound grief over the loss of the previous dog, it is interesting that this finding was not also noted in the assistance-dog handler group, who also described strong feelings of grief over their previous dog.There are two possible reasons for this.First, perhaps assistance-dog handlers also have this fear, but the theme simply did not arise during the discussion.Had they been explicitly asked whether they feared getting hurt again, they may have answered affirmatively.Second, assistance-dog handlers may be motivated to obtain a successor dog despite the fear of getting hurt again, due to the major negative impacts of not having a dog (e.g., loss of independence, lack of a necessary disability support).That is, they are willing to risk the fear of getting hurt because this risk is outweighed by the risk of not having a dog to support them at all.Further research is needed to confirm whether these explanations are correct.

Practical Implications
There are numerous practical implications from this study that may assist in improving human-dog bonds and relinquishment rates: 1) The findings highlight that owners/handlers have certain expectations based on their previous dog.Careful consideration of a dog's desirable and undesirable characteristics is important, as well as increased attempts to match owner and handler preferences with characteristics of the dog, in both companion-animal and assistance-dog acquisition contexts.2) Adoption centers, assistance-dog training providers, breeders, and other dog sources should consider the period since the death/retirement of the previous animal and the level of grief the owner/handler is currently experiencing.3) Given that all but one of the study participants were unaware of the experience of SDS prior to seeing the recruitment materials for this study, more social awareness of this syndrome is required to normalize it and provide necessary supports.Similarly, increased awareness of the key features of SDS through increased training of animal homing and rehoming staff may improve the outcome for both owners/handlers and dogs.4) Overall, increased social awareness about the impact the death of a companion or assistance dog can have on their owner/handler may decrease the experience of disenfranchised grief and enable owners to seek more support over the loss of their dog.

Limitations
There were several limitations with the current study, which should be addressed in future research.First, the sample consisted of only female participants.Therefore, it is uncertain whether the experience of SDS is the same or differs for male owners/handlers.Kidd et al. (1992) reported that women had higher expectations than men that their dogs would provide love, and King et al. (2009) suggest that female dog owners prefer calmer dogs.Given the effect expectations have on SDS, women may represent a sub-population at greater risk of more profound feelings of SDS.Future research is required to establish whether gender or other variables may increase the likelihood and severity of experiencing SDS.
Second, whilst small sample sizes may be appropriate in exploratory studies in order to gain an in-depth understanding of previously unexamined phenomena such as SDS, as indicated by the suggested sample size for projects in Terry et al. (2017), future research using larger sample sizes is required in order to quantify the experience.This future research will assist in developing a scale to measure the experience of SDS, and identify owners who may be experiencing SDS, and interventions to prevent it and aid these owners.
Another limitation is associated with the expression of grief experienced by participants.Whilst there were indicators that the experience of SDS could be associated with clinical levels of grief, no inventory was provided to the participants to confirm this.Additionally, the effect of attachment style on the experience of SDS was not explored.Therefore, future research should attempt to address whether the experience of clinical grief symptoms and attachment orientation are also defining features of the experience of SDS.Exploration of these features will also assist in the development of inventories to aid dog owners/handlers.

Conclusion
In this study, we found seven key features which defined the experience of SDS for both assistance-dog handlers and companion-dog owners.These defining features include a strong bond with the previous dog and ongoing bereavement over its loss; negative emotions towards the successor dog and ownership; and an inability to bond with them due to comparison and unmet expectations.There were three additional features exclusive to assistance-dog handlers: inability to trust new dog; differences in working ability; and a threat to independence.Fear of getting hurt again was the only exclusive feature for companion-dog owners.Additionally, three factors influencing the experience of SDS were time since the loss of the previous dog, and time taken to bond with the successor dog; the participants' previous awareness of SDS as a phenomenon; and the level of community support participants perceived after losing their dog.One of the major findings of SDS, not present in the Guide Dog population, was that it was not linked only to second paired dogs and could be associated with other dog pairings.Thus, this study proposes that the syndrome be re-named Successor Dog Syndrome.

Disclosure Statement
No potential conflict of interest was reported by the authors.

Table 2 .
Focus group schedule.

Table 3 .
The descriptions of the key features defining the experience of second dog syndrome in companion-dog owners and assistance-dog handlers.

Table 4 .
The description of factors which influenced the experience of second dog syndrome (SDS) in companion-dog owners and assistance-dog handlers.