11 Oct 2022
Thomas Webb
Job Title
Recent estimates suggest that up to 6 in 10 dogs and cats are overweight or obese (Bomberg et al, 2017), and the level of overweight and obese companion animals has been described as an “epidemic” (Kipperman and German, 2018).
Risk factors for obesity among companion dogs are multifactorial and include factors pertaining to the dog (such as genetics, breed, neutered status, age, sex and responsiveness to food). However, owners typically control food intake among companion animals and can also moderate energy expenditure (Association for Pet Obesity Prevention, 2014).
Therefore, growing interest exists in collaborative programmes that explicitly target owners’ behaviour, either as part of a multi-component intervention (for example, alongside a nutritional recommendation) or as its primary focus.
A review of 14 behaviour interventions by Krasuska and Webb (2018) suggested they can be effective (the interventions had, on average, a medium-sized effect on outcomes); however, it was also clear that the evidence-base was in its infancy, and a need exists for a systematic and scientific approach to developing interventions, similar to that which has been called for in other domains (such as Michie and Johnston, 2012).
One approach that has proved popular, having been cited more than 2,000 times (according to Web of Science) and included in recommendations to Government (Michie and West, 2013), is described by Michie et al (2014) in their book, The Behaviour Change Wheel: A Guide to Designing Interventions (see also Michie et al, 2011).
The approach suggests that changing behaviour involves first identifying and understanding relevant behaviours, and then using this “behavioural diagnosis” to identify intervention content and ways to deliver that content. Below, the author describes this approach, along with some of the progress that he (and others) have made using it to develop interventions to tackle the challenge of pet obesity.
The first step in applying behavioural science is to define the problem in behavioural terms (for example, that obesity among companion dogs can be the result of their owners’ behaviour), and then select the behaviour or behaviours that contribute to the problem.
For example, when the author conducted a series of focus groups to understand practices around feeding and exercise, owners reported a number of behaviours that could lead to weight gain, including giving leftovers, wanting the dog to be part of celebrations (such as a birthday), and allowing others to feed the dog (Webb et al, 2018).
These behaviours are then specified in as much detail as possible (for example, if an owner reports that their dog receives leftovers, then how often does this happen and when?), including identifying the target individual, group or population of interest (for example, is it only the primary owner that gives the dog leftovers or also those in their household?).
Having specified the target behaviour(s), the next step is to identify what needs to change in the person and/or the environment to achieve the desired change in behaviour.
Michie et al (2014) suggest that this question can be approached using the “COM-B” model, which proposes that behaviour is determined by “capability” (that is, the person or people concerned must have the physical strength, knowledge, skills, stamina and so forth to perform the behaviour); “opportunity” (that is, the extent to which there is a conducive physical and social environment); and “motivation” (that is, the person must want to change their behaviour to achieve the desired outcome).
For example, an owner who feeds leftovers needs to want to change this behaviour (for instance, they recognise that it contributes to obesity, and that this is a problem for them and their dog), feel capable of doing so (for example, they have a way to distract their dog when they are eating), and have the opportunity to do so (for example, they have somewhere to put leftovers out of reach of the dog).
To investigate whether owners’ motivation, opportunity, and/or capability influence obesity among companion dogs, the author and others (Webb et al, 2020) recruited a relatively large sample of dog owners from France, Germany, the UK, Italy and Russia (N = 3,339), who completed a questionnaire designed to measure variables reflecting capability, opportunity and motivation. Owners then submitted a photograph of their dog from which the authors assessed its body condition (BCS).
The findings suggested that factors reflecting capability (such as perceived costs associated with ownership), opportunity (such as social support from friends), and motivation (such as beliefs about the dog’s vulnerability to the threat of obesity, normative beliefs about feeding) all predicted BCS over and above demographic factors (such as the dog’s age and neutered status).
Taken together with existing research, the authors concluded that interventions targeting owners’ behaviour to reduce pet obesity likely need to increase capability, opportunity and (author’s emphasis) motivation.
This understanding of relevant behaviours can then be used to inform the choice of strategies designed to support owners to change their behaviour, if required.
At this point, it can be valuable to consult taxonomies – or lists – of potential strategies. For example, the BCT v1 taxonomy (Michie et al, 2013) describes 93 different behaviour change techniques (or BCTs) within 16 broad categories.
Selecting an appropriate strategy or combination of strategies can be done on the basis of theory (for example, Michie et al [2009] found that interventions that combined self-monitoring with at least one other technique derived from “control theory” [Carver and Scheier, 1982] were more effective than those that did not), or by selecting techniques that are agreed to target specific issues (for example, an owner who feeds treats because they do not feel capable of managing their dog’s behaviour in other ways may be provided with skills training).
This latter approach is referred to as “intervention mapping” (Bartholomew et al, 1998), and Michie et al (2008) provided an example of how it can be used to map the putative determinants of behaviour (such as capability, opportunity and/or motivation) on to specific behaviour change techniques.
While intervention mapping provides a principled way to identify strategies that may support owners, it is currently complex and requires training in behavioural science.
What is needed are user-friendly tools that can help owners (and the professionals working with those owners) to identify relevant behaviours, reflect on why they occur and then use these insights to suggest strategies to support change.
Some examples of such tools exist: for example, Armitage (2008) described the idea of a “volitional help sheet” that can help owners to form “if-then” plans, known as implementation intentions (Gollwitzer, 1999). The help sheet prompts people to identify potential challenges/opportunities from a list, and then select potential responses to these situations.
With the support of Purina, the author developed a similar help sheet to aid dog owners to manage obesity (Webb et al, 2018), and is working with the Pet Food Manufacturers Association to integrate this into their Healthy Weight Hub (bit.ly/2WJv2xU).
Such tools designed for the owner are likely helpful, but behavioural science also needs to be a core part of veterinary practice, such that “behavioural consultations”, “behavioural diagnoses” and “behavioural support” are given the same credence as, for example, nutritional consultations and guidance.
No doubt exists that using behavioural
science to understand and change owners’ behaviour with respect to their companion animals likely forms part of tackling the challenge of overweight and obese companion dogs.
However, while veterinary science can translate evidence from other domains, investment will also be needed to design interventions based on the principles of behavioural science, and to collect robust data that can be used to understand what works, when, for whom, and why.
Adopting systematic and scientific methods will enable veterinary science to not just benefit from, but contribute to, the cumulative science of behaviour change (Michie and Johnston, 2012).
This evidence then needs to be translated into user-friendly tools that owners can use to change their behaviour and veterinary professionals can use to support owners in this journey.
