It is widely recognised that obesity in cats and dogs is a complex, multifactorial (Loftus et al, 2014), incurable (German et al, 2009, 2011a) disease (Day, 2017). Obesity in pets reduces their quality of life (German et al, 2012) and their lifespan (Kealy et al, 2002), and it was the top welfare issue identified by veterinary practices in a recent survey (PDSA, 2020). One study reported median lifespan was shorter in overweight dogs or dogs with obesity when compared with an ideal weight (Salt et al, 2019). In cats a similar observation was made, with shorter lifespans where the cat was overweight or obese (Teng et al, 2018). With 65% of all dogs, 37% of juvenile dogs and 39% of cats in the UK reported to be overweight or have obesity this disease is affecting pets at epidemic proportions (Courcier et al, 2010; German et al, 2018).
Recently there have been changes in the nation's homelife with repeated lockdowns, more pet owners working from home and the reported increase in treats and human food being given to pets (PDSA, 2020). This undoubtably decreases the opportunity to have meaningful conversations about a pet's weight. As a result, the current situation and indeed the future, weighs heavily on the veterinary industry's shoulders.
Addressing this disease may feel overwhelming at times because of the complex nature of the disease and the importance of client compliance with weight loss success (Churchill, 2016). Veterinary staff may also lack the leadership or communication skills required to implement protocols in their veterinary practice. In addition, many veterinary professionals feel conversations with clients about obesity in pets are difficult and fear appearing judgemental and damaging the trust (Heinze and Linder, 2013; Larsen and Villaverde, 2016). The human–animal bond benefits both humans and animals, but it has also been noted that the anthropomorphic nature of these bonds, can be associated with behaviour issues and obesity (Wensley, 2008). All is not lost, however, there are some fundamental actions that can be taken to make a difference, and a survey by Marsden (2019) reported 88% of pet owners said if they felt they could protect their pet from illness, they would work with their veterinary surgeon to help their pets lose weight.
Albert Einstein is widely credited with saying: ‘The definition of insanity is doing the same thing over and over again but expecting different results'. Therefore, when it comes to cats and dogs with obesity, what can be done differently today to directly impact those pets with obesity? Like any mountain to climb, it is the combination of smaller steps by all of us that will lead to a greater overall chance of success, rather than attempting fewer, more daunting, large or complex ones (Nawas, 2020; Robinson, 2020).
Simple things to implement today that will make a difference
Talk about pet obesity, without judgement or prejudice, to everyone, every day
Veterinary practices can be reluctant to openly discuss pet obesity for fear of alienating or jeopardising relationships with their clients. One report lists ‘concern over offending the client’ as one of the top reasons for failing to discuss pet obesity (Packer et al, 2012). Another study indicated that the most common obstacles in discussing obesity with pet owners were lack of time and a fear of losing the client (Aldewereld, 2018). One solution is to utilise the skills of a veterinary nurse and refer for a further consultation — a full history can be taken and nutritional advice given as part of a holistic obesity care plan. This requires mutual trust and teamwork, and a need for a practice approach to obesity.
Research into human obesity has shown that referring to obesity as a medical condition may reduce stigma, by maintaining the focus on the disease status and the subsequent reduction of blame (Ata et al, 2018; Nutter et al, 2018; MacInnis et al, 2020). Weight bias against humans with obesity can impair health care (Chapman et al, 2013; Kyle and Puhl, 2014; Alberga et al, 2019) and a recent veterinary study has highlighted similar results (Pearl et al, 2020). Human health care organisations have altered their language and replaced some terms with more non-stigmatising and patient-centred language with success (Stanford and Kyle, 2018).
Changing derogatory words such as ‘fat’ and ‘chubby’ and replacing them with ‘above ideal weight’ or ‘pets with obesity’, avoids the possibility of minimising the disease status and its impact on the pet's quality of life. Much can be learned from this change of language in human obesity care, as it has proven to be important and impactful (Albury et al, 2020).
Clients are more likely to come for help and advice if they have never felt judged or uncomfortable. A way to gain trust with pet owners is to reframe your words, from direct questioning to an invitation for the pet owner to tell you about their pet's eating habits, or favourite treats. This builds rapport and increases success (Ward, 2017).
Weigh, body condition score and record every pet, every visit
Research into human obesity shows that weighing yourself daily is positively linked to successful weight loss and longterm weight maintenance (VanWormer et al, 2008; Pacanowski et al, 2014). Studies show, however, that veterinary practices infrequently record weight and body condition score (BCS) during consultations (German et al, 2008) and rarely record if a dog or cat is overweight or obese in their clinical notes. The presence of orthopaedic disease appears to prompt recording, however further research is warranted (Rolph et al, 2014).
BCS uses visual and palpable characteristics to estimate the degree of obesity in cats and dogs. The fat covering of the ribcage, the presence or absence of a waist and any abdominal fat deposits are assessed and compared with a score chart (Cline et al, 2019). Freeman, at al (2011) advises using a consistent method to assess current status and changes over time. Both 5 and 9 point scales are commonly used. With the 5 point scale, ideal bodyweight is scored as a 3, with 1 emaciated and 5 having obesity. On the 9 point scale, a 4 and 5 are ideal bodyweight, and each score higher represents a 10% increase above ideal bodyweight. A pet with a BCS of 9/9 is 40% above ideal bodyweight and has obesity. A BCS assigned using the 9 point scale has shown to be well correlated with body fat percentage when measured by DEXA in both colony and client owned cats and dogs. The WSAVA provides a nutritional toolkit including 9 point BCS charts for cats and dogs — https://wsava.org/wp-content/uploads/2021/04/WSAVA-Global-Nutrition-Toolkit-English.pdf (Figures 1 and 2).


Prevention is better than cure, and spotting trends early in a pet's weight trajectory, combined with proactive, ongoing bodyweight and BCS monitoring, can help address impending problems rapidly and goes some way to improving the pet obesity epidemic (Brooks et al, 2014; German, 2016).
Leclerc et al (2017) found that Beagle puppies with a BCS >6/9 at 7 months old were more likely to develop obesity as adults, which indicates that a risk factor for obesity in adulthood, is obesity during growth. Given the prevalence of overweight and obesity in growing dogs (German et al, 2018), bodyweight and BCS monitoring should start at initial vaccinations and continue throughout life, combined with an appropriate, responsive, nutritional recommendation. Understandably, this can be a challenge, given the previously discussed lack of time, team approach to obesity and the reduced face-to-face consultations of current times.
Monitoring of correct growth in puppies can now easily be performed with the use of evidence-based growth charts, which are freely available for use by veterinary professionals at https://www.waltham.com/resources/puppy-growth-charts. The charts allow growth to be plotted against what is considered to be ideal growth, thus highlighting abnormal growth, and if this is detected, further investigations can be instigated (Figure 3) (Salt et al, 2017). Kitten growth charts are currently under development.

However, this should not just be limited to growing pets. BCS combined with bodyweight monitoring and recording, can assist in identifying pets at risk of developing obesity (Freeman, 2011).
Feed an appropriate diet, for maintaining or achieving a healthy weight
To achieve a healthy weight in pets, an appropriate diet must provide complete and balanced nutrition, it should deliver the correct number of calories and should be adjusted for each life stage as the pet ages (FEDIAF, 2020). WSAVA published its Global Nutritional Guidelines in 2011 to provide evidence-based nutritional information for companion animals to support the veterinary team (Freeman et al, 2011).
In neutered cats and dogs, there is a key link to obesity — neutered dogs are 2.8 times and neutered cats are 3.6 times more likely to have obesity than their sexually intact counterparts (Roberston, 2003; Courcier et al, 2012). One of the downsides to neutering is reduced caloric need, a 30% reduction in resting energy expenditure has been reported post neutering in cats of both genders (Root et al, 1996; Martin et al, 2001). A higher frequency of obesity was reported in dogs that were neutered between 5 and a half months and 12 months old, compared with those that were neutered before 5 and a half months old (Spain et al, 2004a). However, this could not be confirmed in cats (Spain et al, 2004b).
In cats and dogs the daily caloric intake needs to be restricted further, typically between 30–50% less, to achieve the desired weight loss (German et al, 2008). The energy intake required to achieve weight loss has been reported to be 63 ± 10.2 kcal/TBW(kg)0.75/day (TBW is total body-weight) for dogs (Flanagan et al, 2017) and 52 ± 4.9 kcal/TBW(kg)0.75/day for cats (Flanagan et al, 2018). Care should be taken so nutrient deficiencies are avoided; hence the gold standard recommendation is the feeding of specific weight management diets. These diets are formulated to be nutrient dense and calorie dilute to ensure safe, effective weight loss and weight maintenance (Linder et al, 2013; Flanagan et al, 2017).
One of the main concerns when starting an obesity care programme for owners, is the fear that their pet will be hungry (Murphy, 2016), so recommending a weight loss diet that supports satiety (the feeling of fullness) and reduces food seeking behaviours would be ideal. Human studies show that some foods are more effective in reducing hunger than others, and foods higher in protein, fibre, and carbohydrates are the most satisfying. Results from a trial performed by Weber et al (2017) indicated a similar effect for cats and dogs — a diet containing high protein and high fibre had a greater satiating effect than either just higher protein or higher fibre alone for dogs. Cats require a diet higher in fibre with moderate protein levels to maximise these effects (Hours et al, 2016).
Weight re-gain is common in cats and dogs; a 2011 study suggested that nearly 50% that completed a weight loss programme re-gained some or all of the weight they lost (German, et al, 2011a), and dogs specifically will revert to a similar starting level of obesity faster, and with less calories than they needed to become obese initially (Nagaoka et al, 2010). The energy needed to maintain an ideal weight post weight loss is lower than the energy needed by cats and dogs that have never had obesity (German et al, 2011a; Seriser, et al 2011). Cats and dogs are 20 times less likely to regain weight if they remain on a specific weight management diet, so it is therefore recommended that patients remain on the weight loss diet long term, in order to prevent weight rebound. It is for this reason that obesity is considered an incurable, but very treatable disease (German et al, 2009; German et al, 2011a).
Weigh out the food, using digital scales, every day
A study by Marsden (2019) showed a lack of portion control could be contributing to pet obesity, with 32% of pet owners guessing pet food portions. For those that use measuring cups, the news is not much better as measuring cups have been shown to be wildly inaccurate, with poor accuracy ranging from 18% under to 80% over the desired portion size (German et al, 2011b).
These inaccuracies, could be contributing to the insidious weight gains that are observed in pet obesity. Weighing out daily portions with digital scales, is a simple recommendation that can be made to all pet owners to help maintain a healthy weight or aid in obesity care programmes, and can easily be the difference between success and failure (Murphy, 2016).
Conclusions
The rising trend of pet obesity is concerning for both veterinary practices and pet owners, affecting the health, longevity and quality of life of cats and dogs. However, there are actions that can be taken and by achieving the fundamental elements of obesity care we can hope to see a collective benefit. A healthy weight is achievable for all cats and dogs, by selecting a diet that supports optimal nutrition, appropriate calories and meal satisfaction, combined with accurately measuring food intake and regular weighing and monitoring of the pet. Client recognition of the consequences of an obesity diagnosis and an acceptance to change their habits is also key. The ability of veterinary professionals to alter the language they use, along with the nutritional and habitual recommendations they make, can be central to achieving greater compliance and improving patient health (Kyle et al, 2014; Stanford et al, 2018; Teng et al, 2018; Alberga et al, 2019; Salt et al, 2019; Pearl et al, 2020). Together we can make a difference.
KEY POINTS
- Obesity in cats and dogs, is a complex and incurable (but treatable) disease which negatively affects quality and longevity of life.
- Tackling this disease can feel overwhelming at times but there are some simple steps we can implement to make a difference.
- Talking openly about obesity, to pet owners without judgement, can improve trust and overall success.
- Weighing and body condition scoring pets and recording these values regularly, from early on in life can help us spot trends.
- Recommending a diet appropriate to the pet's caloric needs, whilst ensuring meal satisfaction and limiting food seeking behaviour, can help achieve or maintain a healthy weight.
- Daily weighing of this recommended diet on digital scales can also aid success.