A total of 8 charity service users were assessed as meeting the eligibility criteria between August 2019 and March 2021. Overall, 6 service users gave consent to be contacted, with 4 individuals consenting to be interviewed and included in the study. An additional 2 participants self-selected to the study by responding to digital advertisements circulated via social media. A total of 6 participants were included in the study, 3 males and 3 females.See Table 1 for socio-demographic characteristics. The study sample size was concordant with IPA theoretical guidelines and previously published studies, which recommend 4–10 participants [24, 29,30,31].

Table 1 Sociodemographic characteristics of study sample

Throughout the IPA analysis, 7 subordinate themes emerged concomitant to 4 superordinate themes of protective partnership, positive behavioural change, facilitating meaningful social connections, and loss-orientated cognitions. To ensure transparency in the idiographic nature of the analysis, a coding tree of superordinate and subordinate themes is included below (see Table 2). Excerpts of participant data are included in the text to evidence that the interpretation is grounded in the data, which allows the reader to re-examine the interpretation of the data and assess for internal coherence.

Table 2 Coding tree of superordinate and subordinate themesProtective relationship

All participants described a deep and meaningful relationship with their CA, where the primary benefit of the CA is connected to the human-animal bond and the emotional support this affords. In the context of adjustment to advanced illness, this human-animal bond appears to transcend to a greater significance comparable to a human-like attachment [9]. Uniquely, this change is considered a surprising aspect of their illness journey, regardless of whether CAs have been a longstanding feature or are a relatively new part of the individual’s family system.

The significance of the protective partnership is highlighted by the anthropomorphic language utilised to describe the CA and the general status conferred to the CA within the family system of people with advanced cancer. Individuals living with advanced cancer describe their illness as generating barriers that restrict their access to usual emotional supports, which seemingly precipitates the CA’s new significance. The protective relationship superordinate theme contains three subordinate themes: providing unconditional positive attachments, promoting post-traumatic growth, and expressing the emotional consequences of illness.

Providing unconditional positive attachments

It has been suggested that the beneficial effects of CAs are underpinned by Attachment Theory, [32, 33] and indeed, the protective relationship appears heavily centred on the attachment between the individual with advanced cancer and their animal. Mac, a single man living alone, describes the significance of his CA since being diagnosed with brain cancer:

“Nothing as loving as her. If I am sad, she knows I’m sad and she is very perceptive to me being down or whatever, … I can sense that from her and that gives me a boost and that helps me” (Participant Mac & CA Buster).

Mac explains here that the protective partnership is underpinned by a significant degree of emotional congruence between himself and Buster. Mac suggests that his CA is uniquely attuned to him and that allows them to demonstrate empathy. It is as if Buster fulfils Mac’s need to be understood, which subsequently confers to him emotional support and forms the basis of their protective relationship. The beneficial effects of this positive attachment are heavily centred on Rogerian core conditions of congruence (‘authentic self’, where inner feelings are in line with actual behaviour) and empathy, [34].

The unconditional nature of the attachment between the individual with advanced cancer and their CA is noted as a crucial aspect of the protective relationship. As Claire, a 47-year-old woman with breast cancer, discussing the comfort she finds in her CA explains:

“She just is always so loving and so positive, that if you’re not feeling great and you spend a wee bit of time with her, she just makes you feel a wee bit better *Interviewee becomes emotional*” (Participant Claire & CA Daisy).

Claire explicitly describes the unconditional nature of her attachment with Daisy as an integral aspect of their protective relationship. This significance is emphasised by her description of proximity maintenance, whereby she suggests there are immediate improvements in psychological benefits from simply being close to her CA. It is as if the attachment with the CA instils an increased sense of self-worth in Claire and increases her resilience to the negative consequences of her illness by embodying the Rogerian core condition of unconditional positive regard [34].

Interviewees also described that their unconditional secure attachment to their CA provides them with an increased sense of security and safety while they manage the challenges related to their advanced cancer. As described in Neil’s account below:

“With nobody in the house, he’s there to greet me when I come home and when I go out … He barks to let me know when somebody is coming up the driveway, so he is a wee bit of an early warning system” (Participant Neil & CA Teddy).

Neil’s explanation suggests that his illness generates an increased sense of vulnerability and feelings of loneliness. Neil indicates that his illness has created an interpersonal isolation that the unconditional positive attachment with Buster mitigates against by creating a safe haven and sense of security.

Throughout these accounts the CA is described in a manner that suggests the individual with advanced cancer maintains an almost human-like attachment. The four key features of secure attachment secure base, safe haven, proximity maintenance and separation distress [33] are universally experienced between individuals with advanced cancer and their CA. The unconditional positive attachment between the CA and their owner is an integral part of their protective relationship. This attachment ultimately provides emotional support, which promotes general wellbeing and protects the individual from the negative psychological consequences of their advanced illness.

Promoting post-traumatic growth

Positive psychological change occurring within an adverse experience is referred to as post-traumatic growth (PTG) and has five facets: relating to others, new possibilities, personal strength, spirituality, and appreciation of life [35]. All interviewees described how their CA has engendered positive psychological change throughout their experience of advanced cancer

“There are lots of frightening things and unpleasant things in our lives at the minute, but if you see her running about, you can’t help smiling… I suppose it is trying to appreciate the things you do have, instead of thinking about the challenges that you have in your life or what is ahead of you … It just brings you back to the moment” (Participant Claire & CA Daisy).

Claire acknowledges how her advanced cancer diagnosis has generated significant psychological distress associated with the unknown aspects of her illness and the general sense of disempowerment this has created. Claire’s account suggests that Daisy provides her with a greater appreciation for the positive aspects in her life, which facilitates her being in the present moment. There is a shift from a loss orientated to an acceptance focused stance, which is indicative of her CA facilitating PTG through a greater appreciation of life and new possibilities [35]. Moreover, the CA seemingly exerts a grounding effect on Claire that encourages psychological adjustment and promotes mindfulness coping behaviours [36].

“He is always here; he is my constant. … He knows when I am down, sad, or happy … He is one of the good things in my life and the fact that I have a good family and a very loving family” (Participant Mac & CA Buster).

Likewise, Mac, while describing the significance of his protective relationship with Buster, highlights PTG in two distinct ways. It is as if his protective relationship has encouraged him to consider his own values and in doing so has engendered a greater appreciation for the different aspects of his life. Secondly, PTG is seen in the description of close relationships, where the CA facilitates an appreciation of Mac’s intimate relationships and an acceptance of his increased emotional vulnerability.

Several interviewees denoted PTG in a divergent fashion, highlighting potential spiritual development associated with their experience of their CA throughout their illness. Increased spirituality has been demonstrated as a significant predictor of psychological adjustment to cancer, regardless of the perceived threat to life [37]. As Karen, a middle-aged woman with breast cancer describes following a period of intensive chemotherapy treatment:

“My relationship with my dogs is much deeper now following being ill and the fact that I realise that spiritually they are very connected to me” (Participant Karen & CA Rufus & Lilly).

Karen specifically states that her CA has facilitated a general spiritual development associated with the depth of their protective relationship. Agnes, an elderly lady diagnosed with breast and bladder cancers, provides a similar narrative indicating a spiritual growth associated with her CA. She explains that she feels a previous CA ‘sent’ her current CA to protect her “because she has the same antics as the other dog”.

Unlike Karen, Agnes’s account of spiritual PTG reflects more of an engagement in an existential inquiry relating to the presence of a higher power. The CA in this regard connects the self with a higher presence, which appears to provide Agnes with a sense of wellbeing and emotional support as her illness progresses.

Expressing the emotional effects of illness

All interviewees explained that a significant aspect of the protective relationship with their CA exists in the ability to express the emotional consequences of their advanced cancer with impunity. As Neil, a 66-year-old man who lives alone and describes himself as increasingly lonely following his prostate cancer diagnosis, describes below:

“On the odd day you get a wee bit down and you start thinking about these things and you wonder what you done wrong … I just talk away, whether he’s listening or not, I just talk away. It’s maybe because I can’t get an answer back from him, but it gets it out of my system for a while” (Participant Neil & CA Teddy).

Neil’s narrative suggests that during the process of trying to understand and accept his illness he experiences low mood and increased feeling of self-blame. He implies that Teddy is an unfettered outlet for him to express the emotional consequences of advanced cancer, while also stressing that the lack of reciprocal communication allows him to engage in a safe process of introspection.

George, a married family man, offers a similar account while reflecting on his illness’s impact on his family. He acknowledges the safety of being able to openly express his emotions to his CA in a way that he cannot do with his family: “you don’t need to conceal the pain … He has no cares, no worries”. Although the human-animal bond parallels aspects of human–human relationships [38], it is clear the human-CA protective relationship differs from a human–human relationship, with the latter incurring more considerations that might limit open discourse. In this regard, the CA seemingly offers a unique support to the individual with advanced cancer.

The ability to express the emotional consequences of advanced cancer is a key component of the protective relationship between individual and CA, seemingly embedded in the unconditional nature of the attachment. It provides a direct emotional support to individuals with advanced cancer, allowing patients that safety to communicating the consequences of their illness and express their basic emotional needs. This offers a unique emotional support that provides a stress buffer against the psychological consequences of the advanced illness [8].

Positive behavioural change

As their illness progresses, all individuals described becoming increasingly susceptible to the negative consequences of their advanced cancer. Their accounts indicate that this manifests as a reduced engagement in meaningful activity, due either directly to physical limitations or as an indirect consequence of mood disturbance.

All participants suggested that their CA precipitated some degree of positive behavioural change during their illness. Their accounts highlighted that the CA creates a sense of purpose in the individual that motivates them to engage in positive behavioural change, which subsequently increases their self-worth and facilitates improved wellbeing.

Individuals with advanced cancer described the CA promoting a variety of positive behavioural change, which can be separated into two distinct subordinate themes: promoting behavioural activation and generating routine and structure.

Promoting behavioural activation

All interviewees described experiencing psychological benefits from the behavioural activation that occurs primarily as a result of caring for their CA. Below Claire discusses how Daisy has resulted in her re-engaging in exercise, that otherwise she had felt too unwell to participate in:

“One of the things I get the most out of it, is having to take her out walking, being it is keeping me active … Even if you don’t feel like going out you have to take her out. So that is a sort of a practical thing that I have got from it” (Participant Claire & CA Daisy).

Claire states that the behavioural activation promoted by Daisy is one of the most important benefits of a CA while managing an advanced illness. She highlights that the practical support offered by the CA comes through the activity generated in meeting the CA’s need, which also provides an extrinsic motivation to engage in activity. There is a strong inference that this behavioural activation, which would otherwise be neglected, leads to improvements in Claire’s wellbeing and protects her against depressive consequences of her advanced illness.

The promotion in behavioural activation is interrelated with the protective partnership. As George discusses how his advanced cancer has restricted his usual activity, he explains how the protective relationship with Winston provides him with the safety to engage in novel physical activity: “I got confident to walk around the block… even go out by myself… before I would not go out, so he was getting me out”. As with Claire, the CA facilitates George’s engagement in positive behavioural change that has a positive effect on his overall subjective wellbeing.

Generating routine and structure

Participants described how a significant part of the positive behavioural change attributed to their experience of CA during their advanced illness, relates to the routine and structure created by the CA.

In the extract below, Mac highlights the integral role Buster has had in establishing positive behavioural change through generating new routine and structure for him:

“I would worry about me own mental health … if I didn’t have Buster I wouldn’t get out of my bed for a couple of days and that’s never good for anyone. … If I didn’t have Buster some mornings there would be no reason to be getting up … I don’t know where I would be without them” (Participant Mac & CA Buster).

Similarly, Neil described that Teddy has generated positive behavioural change by providing regular routine and structure to their lives:

“Before I was just lounging about the house … Having to make me own tea, sometimes I didn’t feel like making it… But he changed the routine. I have to feed him so I may as well feed myself” (Participant Neil & CA Teddy).

In both of these accounts features of depression are evident. Mac and Neil emphasise the significance of the routine and structure provided by their CA. Both demonstrate awareness into the negative consequences of their absence of routine and increased levels of apathy, yet they describe a lack of motivation to break this negative behavioural cycle. Through providing the routine and structure necessary to care for their CA, the person with advanced cancer is more likely to engage in their own self-care. The CA inadvertently elicits positive behavioural change that the individual would not have had the intrinsic motivation for otherwise. The significance of the CA generating routine and structure is greater for those with an increased sense of interpersonal isolation and appears less prominent in the accounts of individuals living with partners.

Facilitating meaningful social connections

All individuals expressed the view that their advanced cancer diagnosis generated a sense of increased isolation, which fosters further feelings of loneliness and reduces the perceived availability of social supports. This isolation is a unique aspect of advanced illness that occurs independent of social circumstances; expressed equally by individuals living alone and those living with family or dependents.

Participants highlighted that their CA facilitated their reintegration with others, generating an increased sense of belonging within the individual, which provides them with access to practical and social supports that mitigate the feelings of separation generated by their diagnosis.

Individuals with advanced cancer described their CAs attracting external supports into their lives, which they would have otherwise been without and that they feel to some degree mitigates against the negative psychological consequences of their advanced cancer diagnosis. This would be consistent with literature suggesting that CAs help individuals secure access to practical and social supports [8].

“I’ve got to know a lot more people… It just probably makes you feel a bit more integrated into the whole thing and there probably are people you could ask for support if you needed to” (Participant Claire & CA Daisy).

As a single mother living with a dependent, Claire explains that Daisy facilitates meaningful social connections with others. These connections provide her with the sense of belonging to a community, where otherwise her illness may have led her to feel overly isolated. Claire suggests that these connections could lead to increased social support, which might offer protective factors that mitigate against the negative effects related to the progressive nature of advanced cancer.

Similarly, Agnes suggests that a key benefit of the social connections generated by her CA can be in the emotional support it provides, which can be as simple as others taking an interest in her wellbeing: “they talk to me, ask me how I am doing”. While George highlights that the social connections generated can be just as important for those with more established family units because it provides an opportunity to communicate openly about his cancer and worries, “I talk to people up on the hill… You can talk to a stranger completely”.

Loss-orientated cognitions

Individuals with cancer relate their psychological distress to the unknown and a sense of being disempowered by their illness [39]. Alongside the positive roles CAs maintain for those managing advanced cancer, all interviewees indicated that their CA can also result in a significant increase in their experience of loss orientated cognitions. These loss orientated cognitions relate to the CA being an object to project the own worries and could be separated into two subordinate themes: increased reflection on separation anxiety and focussing on novel limitations.

Increased reflection on separation anxiety

The CA maintains a special place within the individual’s personal system, which relates to the supportive effects of the CA delineated in the superordinate themes: protective partnership, positive behavioural change and facilitating meaningful social connections. Throughout all accounts a concern existed for interviewees as to what might happen to their CAs as their cancer progresses.

“I would have to give her away and that would put me in a worse position because it would genuinely break my heart” (Participant Mac & CA Buster)

Mac describes his fear that as his illness progresses this will lead to an inevitable separation from Buster. It is as if Mac’s account not only highlights his concerns relating to potentially losing Buster and the positive benefits conferred by their relationship. But also, that his interaction increases his focus on his own mortality and increases his own death anxiety.

Likewise, George explains below that during a prolonged period in hospital a facilitated visit from his CA did generate positive effects, but following being separated from Winston he experienced an increased focus on the finality of his advanced cancer diagnosis:

“All of a sudden he was there. Then my wife had to take him away and I suppose that realisation came then, that one day it is going to be for real. That he is not going to see me again” (Participant George & CA Winston).

The fear of loss highlights the significance of their protective relationship, and the benefits Winston confers on George, while also emphasising his projectivity to need support throughout the entirety of the illness. Yet the separation can illustrate the progressive nature of the illness, which increases George’s experience of loss orientated cognitions and furthers his own death anxieties.

Focussing on novel limitations

The other loss orientated cognitions described by interviewees related to being unable meet the CA’s care needs, attributed to the physical and psychological consequences of advanced cancer. The participants’ accounts suggested an aspect of caring for a CA while managing an advanced cancer diagnosis is the potential emphasis it can place on their own novel limitations.

“Frustrating because I can’t take her out as much. … I have to depend on people to help … I did try and take Buster out a couple of times and I actually took seizures” (Participant Mac & CA Buster).

Mac’s account emphasises feelings of guilt as he perceives his illness has gradually restricted his ability to meet Buster’s needs. Mac further explains that he has engaged in increased risk taking to meet Buster’s needs, which we can infer is an attempt to alleviate the negative effects of being confronted by the physical limitations of his progressive illness.

These functions appear connected to the reciprocity of the positive relationship between the individual with advanced cancer and their CA. As the illness progresses, the individual can no longer meet the CA’s needs as before. The CA then becomes a reminder of their own, inevitably increasing physical limitations, which perpetuates further loss-orientated cognitions.

Participants emphasised that the negative psychological consequences of loss-orientated cognitions were lessened by external social supports, attributed primarily to the CA led reintegration with others. As Neil explains below, a pet charity supports him in meeting Teddy’s needs and provide him with a sense of gratitude for the alleviation of his loss-orientated anxieties:

“The (organisation) has that all in hand you know. If something happens or I go into hospital, you know, he is looked after, so I am very grateful for them” (Participant Neil & CA Teddy).

Additionally, any negative effects highlighted by interviewees would often be followed by a rationalisation or vindication of their CA, through the participant citing that the benefits of their CA outweigh any negative aspects.

“It is certainly not a challenge because of the way I feel about Buster… There are more benefits, than hindrances” (Participant Mac & CA Buster).

As Mac explains here: the unconditional protective relationship he maintains with Buster and the positive effects conferred by the significance of this human-animal bond, justify any challenges from living with a CA while managing advanced cancer.