23 Feb 2021
Mike Davies
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Image: © Yakobchuk Olena / Adobe Stock
Despite the thousands of column inches already devoted to the management of pet obesity in the veterinary press, company marketing and practice educational materials, little progress has been made in controlling the current epidemic, with approximately 50% of UK pets still considered to be overweight or obese.
In this article, the author shall review some of the basic principles and some scientific publications listed on PubMed during 2020 that may throw further light on the topic, and may help provide practical solutions.
Strategies to manage pet obesity include prevention as well as treatment – and in both cases owner compliance is critical for success. For some clients, education about the health risks associated with obesity will suffice to motivate them into positive action, but for many the incentive is insufficient, and they will not diligently practise weight control or participate in weight reduction programmes.
It is important to have a detailed conversation to identify what owner opinions are and to develop a strategy to engage with them to get compliance.
According to Porsani et al (2020), weight loss was not satisfactory (lower than 1%) in 64.4% (n=47/73) of dogs, and 44.7% (n=21/47) of owners did not follow diet and physical activity recommendations. A significant association (p=0.01) existed between owner compliance and satisfactory weight loss rate; however, no association existed between weight loss success, diet composition, sex, reproductive status, age of the dogs and their physical activity (p≥.05) – suggesting non-compliance is the most important factor.
Attitudes of practice staff are also critical to success – and it is important not to make hasty assumptions about owner attitudes. According to one study (Pearl et al, 2020), veterinarians and students reported feeling strong emotions – “more blame, frustration, and disgust” – towards obese owners and their obese dogs than towards lean dogs and their owners (p<0.001). Obese owners were assumed to have caused their dog’s obesity and staff were pessimistic about treatment compliance.
This is not a good start, as negative attitudes can result in poor communication and alienation. Try not to make clients feel guilty – even if they are responsible for their pet’s weight problem.
Recent studies have shown adverse effects of obesity, including impaired renal perfusion with increased markers of glomerular and tubular damage (Liu et al 2020); increased plasma oxidative stress, impaired heart rate variability and reduced cardiac systolic function compared to non-obese dogs (Pongkan et al, 2020); and that weight loss in obese dogs can induce positive changes in salivary proteins associated with immunity, inflammatory status, oxidative stress and glucose metabolism (Lucena et al, 2020).
Client education can start with posters and pamphlets in the waiting room or e-newsletters, but personal direct discussion with staff and provision of specific advice tailored to the individual pet is more effective.
Reception staff, nurses and vets should work together to identify overweight pets and recommend weight control/loss strategies.
Many practices and their clients find weight control clinics advantageous, and these can be successfully combined with puppy, behaviour, geriatric or arthritis clinics, which is helpful as clients may find the latter easier to comply with.
Owners should be given simple, clear verbal and written instructions on how to manage their pet’s weight from day one. Providing information about the health risks associated with obesity is important – and in many practices giving owners body condition score (BCS) charts is very helpful – but owners of both dogs and cats do have difficulty assessing the BCS of their pet (Teixeira et al, 2020)
It is important to recommend good nutrition during pregnancy. Puppies with the lowest birth weights are predisposed to develop obesity in later life (p=0.032; Mugnier et al, 2020), with a 70% prevalence of obesity among dogs with low tissue mass birth weight versus 47% in dogs born with high tissue mass birth weight. Overweight was also associated with advancing age and in neutered dogs (p=0.029 and p=0.005, respectively).
Obesity needs to be avoided during growth and young adulthood. Genetic inheritance is now known to be a problem in some dog breeds – for example, the Labrador retriever and flat-coated retriever (Raffan et al, 2016) – and new owners may not realise this, so it is important they are advised to control calorie intake, and avoid treats and snacks between meals throughout life.
Ideally, breeders should identify and breed away from dogs with a genetic profile predisposing them to be obese. Having owned Labrador retrievers himself, the author feels it cannot be much fun for them to feel hungry all the time, and to be chastised for their begging and food stealing behaviour.
In children, being overweight is related to their parents’ permissive style of parenting. In a recent study (van Herwijnen et al, 2020) 2,303 Dutch dog owners completed a modified 32-item parenting styles and dimensions questionnaire used in people, and overweight/obese dogs were overrepresented in the quartile of dog owners with the highest level of permissive parenting. Supplementary logistic regression analyses showed risk factors for a BCS of 6 or higher included having little exercise, being of older age, neutered or owned by someone with lower level education. It is important to address dog owners’ permissiveness in parenting their dogs.
A recent study (Juliana et al, 2020) reaffirmed that older dogs were more likely to be overweight, and joint activity and participation in dog sports could reduce the likelihood of them being overweight. Therefore, regular exercise (short periods of 20 minutes if the dog has difficulty) is important unless medically contraindicated.
Interestingly, in this study owner-reported food-related behavioural problems (for example, stealing food or overeating) were clustered together with other problem behaviours, including excessive barking and aggression.
Studies have clearly demonstrated that lifespan is decreased in dogs that are overweight (Salt et al, 2019) – and in one study (Kealy et al, 2002), increased longevity (by 18 months) and delayed onset of age-related diseases (by two years) was demonstrated in dogs fed lower amounts of food (25% less) than a control group over their lifetime.
The healthier and longer‑lived group had a mean BCS of 4.6, so to extend life and delay onset of age‑related disease, dogs should be kept lean and mean (with a BCS of 4.6).
A useful strategy to prevent overweight is to recommend feeding foods at the lowest feeding rate on the feeding guide. Intake can be increased if the dog loses weight.
Simply reducing the amount of a maintenance food can be successful in inducing weight loss – as demonstrated by Keller et al (2020), in whose study weight loss was achieved in 56/67 dogs (84%), losing a median of 4.7% (range 15.2% loss to 10% gain) of their starting bodyweight (SBW). Weight loss was also seen in all 17 cats, losing a median of 6.4% (range 2% to 15.2% loss) of SBW.
However, this strategy resulted in less than National Research Council‑recommended intake of some essential nutrients, including choline, potassium, riboflavin and selenium.
Nutrient concentrations need to be increased per 1,000kcal in low-calorie weight loss diets to ensure adequate intake. Reduced food intake also causes begging behaviours, so strategies to improve satiety – such as inclusion of high fibre, water or air – can be used.
Foods formulated using higher-quality ingredients with higher digestibility reduces the amount of extra food (and calories) needed to meet nutrient requirements – and, of course, owners need to be reminded to avoid treats and snacks because of the high calorie count they can contain.
Special diets have been developed that can modify gene expression in dogs prone to be obese to increase energy use and cause weight loss.
Fixed formula foods can be fed to avoid large swings in calorie content between batches.
Regular exercise is important. For lethargic patients, exercise can be increased (time, distance and intensity) gradually over a few weeks.
Always set realistic, achievable targets for owners with a visual way of demonstrating success, such as the use of charts, as perceived lack of success leads to disillusionment and increases the risk of non-compliance.
In the author’s opinion, the optimal body condition score is not 5/9 (or 3/5) as depicted on BCS charts – for longevity and to delay onset of age-related disease, it is best to keep dogs lean and mean, and aim to maintain a BCS nearer to 4.5/9.
In humans, bariatric surgery is commonly deployed for patients with morbid obesity who are unable to lose weight.
Gastric banding has also been reported in a dog (Vedrine et al, 2020). An intragastric balloon was placed endoscopically in the stomach. The dog was a 57.6kg, nine‑year‑old neutered female Labrador retriever with chronic hypothyroidism. Its weight had dropped to 40.9kg at the time of intragastric balloon removal after 198 days.
Bodyweight and condition needs to be controlled in pets from birth and throughout all life stages to maintain good health, maximise life expectancy, and to delay or prevent the onset of obesity and age-related diseases.
Control of food intake, regular exercise and – most importantly – owner education to ensure compliance is of paramount importance.
Mike Davies
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