Pet obesity is a growing and complex challenge facing veterinary professionals. While this is a multifaceted issue, we are advancing our understanding of it on multiple fronts, from learning more about effective weight loss programmes to increasing our awareness of owner beliefs and behaviour. As we develop new insights, we become better equipped to tackle what can often be a challenging condition.
Risks of obesity and benefits of weight loss
Obesity is considered to be one of the most common medical conditions in pets worldwide (German, 2016). Estimates suggest about 6 in 10 pet dogs and cats are over their optimal bodyweight (Bomberg et al., 2017), and the issue is growing, with 9 percent of dog owners and 5 percent of cat owners reporting their pet gained weight during the pandemic (PDSA, 2021).
Obesity and overweight status are associated with multiple adverse health and welfare effects in dogs and cats. Poorer quality of life and shorter median lifespan has been observed, as well as functional impairments and co-morbidities such as diabetes mellitus, osteoarthritis and urinary issues (Lund et al., 2006; German, 2016). Studies have shown weight loss in obese patients improves insulin sensitivity, respiratory function and quality of life, as well as enhancing mobility in obese dogs with osteoarthritis (Marshall et al., 2010; German, 2016).
Studies have shown weight loss in obese patients improves insulin sensitivity, respiratory function and quality of life, as well as enhancing mobility in obese dogs with osteoarthritis
Some benefits of weight loss will be purely mechanical, such as decreased loading of joints, while others will result from altering the metabolic state. As we delve further into nutritional science in obesity, we are discovering more about how particular weight loss diets can adjust metabolism to support overall health.
New evidence for metabolic benefits of weight loss programmes
Exciting new evidence highlights the wide-ranging biochemical and immunological effects of weight loss interventions in obesity. Of particular note is a 2020 study of otherwise healthy obese dogs, which examined the effect of a six-month weight loss programme based on a dry diet designed for weight management (Piantedosi et al., 2020). The diet, which contained high protein but low carbohydrate and fat levels, was formulated to stimulate resting metabolic rate and encourage fat loss while maintaining muscle mass and satiety. A high fibre and complex carbohydrate content was also used to promote steady blood glucose levels.
Results revealed the weight loss programme was associated with not only increased activity and quality of life, but also improved metabolic and immunological status. Levels of pro-inflammatory cytokines including tumour necrosis factor alpha and interleukin-6 decreased significantly in obese dogs over the six-month programme (Figure 1), implying a homeostatic recovery of the immune response. An improvement was also identified in certain cardiovascular parameters including troponin-1 levels.
This new evidence underlines the value of such weight loss programmes from a preventative healthcare perspective, as metabolic recovery would be expected to reduce incidence of future health issues. The study also highlights the potential for success with appropriate programmes, as 91 percent of obese dogs showed a reduction in body condition score (BCS). Translating such remarkable success rates into practice, however, is the real challenge.
The challenges of weight loss programmes
Though effective nutritional approaches are available for obese pets, weight loss is often difficult to achieve and maintain. Owners face a multitude of hurdles: firstly, to identify that obesity is present and recognise that it is a problem; secondly, to believe they can address it and gain the motivation to do so; thirdly, to make an effective plan; fourthly, to follow it until the goal is achieved; and finally, to maintain the desired weight longer term. All these stages can represent real barriers and the value of support from the veterinary team cannot be underestimated.
For veterinary teams looking to help owners in this situation, the ability to provide effective support can be enhanced by an understanding of owner beliefs and behaviours associated with pet obesity
For veterinary teams looking to help owners in this situation, the ability to provide effective support can be enhanced by an understanding of owner beliefs and behaviours associated with pet obesity. This is another area where research is extending our knowledge ever further.
Advances in behavioural science
Research indicates that owner identification of obesity is a key aspect to concentrate on. Difficulties here have been recognised for some time: in one study, underestimation of body condition by owners was identified as the most important risk factor for obesity in cats (Cave et al., 2012). More recently, a 2020 study found that 33 percent of owners of overweight or obese dogs rated their pet’s BCS as normal (Webb et al., 2020). This remarkably high figure underlines the importance of educating owners to assess BCS and identify when their pet is an “ideal” weight.
Interestingly, however, the same study found that owners of overweight dogs tend to be more likely to think about their dog’s weight. This suggests that while BCS underestimation is a significant problem, many owners do recognise the issue to some extent and may be open to engaging with interventions.
Another key finding was that owners of overweight dogs were less likely to have social support from friends for exercising their dog. This suggests that interventions to increase social support, such as encouraging owners to walk with friends or develop social networks around dog walking, may be valuable. Practices could even take a more proactive role by offering owners with pets on weight loss programmes the opportunity to connect with each other and arrange dog walks together.
Practices could even take a more proactive role by offering owners with pets on weight loss programmes the opportunity to connect with each other and arrange dog walks together
Each new finding in the field of obesity helps further support clinicians when managing this prevalent and challenging disease. As our understanding of obesity pathophysiology and behavioural science advances, we continue to learn more about potential interventions. However, the ultimate effectiveness of any weight loss programme depends on its uptake by owners, so selection of interventions should be tailored to the individual, based on what will be most beneficial for them. Alongside research findings, communication remains key to help maximise the likelihood of successful management of obesity.