At first it seems as though healthy weight management in dogs should be quite simple. After all, it’s just about balancing the amount of energy in versus the amount of energy out. Yet it’s clear from the number of overweight dogs that it’s not as easy as this. There’s a variety of factors that influence body weight control – a mix of genetics, biology, behaviour and environmental factors. This complex conundrum applies equally to people and dogs and explains why a recommendation to simply “eat less and move more” doesn’t always deliver the required results. It doesn’t mean that a weight loss plan based on lowering calorie intake and increasing exercise will always be unsuccessful, but it’s important to recognise that many different factors are at play for each individual dog. As veterinary professionals dealing with overweight patients, we must acknowledge we are unable to control some of these factors and focus our efforts on the ones we can impact.
Balancing calories and nutrients
When considering reducing calories, it’s important to consider the nutritional needs of dogs. Simply eliminating human food snacks or leftovers is unlikely to result in significant weight loss for most dogs and cutting down the sizes of their regular dog food portions too drastically can result in nutritional deficiencies over time. However, for many dog owners the reduction or elimination of human food snacks or leftovers and careful portioning of their dog’s regular diet may be manageable first approaches to try for a set period of time. Encouraging an owner to keep a “food diary” for their dog and revisiting the veterinary practice for regular weighing during these early weeks will make it easy to see if this approach is proving effective.
For many dog owners the reduction or elimination of human food snacks or leftovers and careful portioning of their dog’s regular diet may be manageable first approaches
Specialist diets designed to help pets lose weight are still nutritionally balanced, but have fewer calories per gram, meaning they are more nutrient-dense and less energy-dense. This means the pet can still have a filling portion that provides all their essential nutrients while providing them with the calorie deficit they need to shift the pounds. Specialist diets can, therefore, be appealing to an owner who suffers pangs of guilt at feeding only a small portion, and feeling full may help limit begging behaviour from pets, which can damage owner compliance with a diet plan! Simply cutting back on a dog’s regular diet is likely to result in too great a nutritional restriction, so recommending a specialist diet is an important step in implementing an effective and safe weight loss plan.
Healthy weight management – a lifelong journey
A weight loss plan is important for overweight or obese dogs but, as with everything, prevention is better than cure. Keeping dogs lean and healthy may seem challenging but it is easier than dealing with excess weight later. Maintaining a healthy weight is a lifelong journey for dogs, with different challenges at each life stage.
Early life and growth
Puppyhood is the perfect time to get into the routine of monitoring weight, not only to track growth and highlight any potential issues early on, but also to get new pet owners into the habit of checking their dog’s weight and body condition regularly. It’s also good for owners to have regular contact with their veterinary practice to discuss their pet’s weight (even if it’s just to reassure and congratulate them that everything is just as it should be).
[Puppyhood] is a crucial period in development and it is important that the right support is in place to minimise the chances of problems occurring
Maintaining a healthy weight for life starts with healthy growth in puppyhood; however, tracking healthy growth can be a challenge as it can be hard to know the correct weight for a puppy, or how much weight they should be gaining between visits to the practice. While body condition scoring can provide some guidance as to whether an individual is over- or underweight, it is not specifically adapted to growing puppies. Also, once early vaccinations are complete, puppies often do not visit the veterinary clinic again until either neutering or booster vaccinations. This means that there is a long period during early life when a puppy’s growth is not assessed and no veterinary guidance is given to owners. This is a crucial period in development and it is important that the right support is in place to minimise the chances of problems occurring.
A scientifically validated puppy growth chart, such as one of the WALTHAM Puppy Growth Charts, is a valuable tool to help during this period. Single weight measurement is useful and provides a guide that enables the puppy to be compared with others at a similar age; however, on its own the chart does not confirm that the puppy has developed normally, and/or will do so in the future. The process of growth monitoring involves taking a series of weight measurements over a period of time and plotting them to determine whether a puppy is developing normally (ie at a healthy rate). This is done by comparing the puppy’s individual growth chart with the growth trajectories of a large population of healthy puppies known to be developing normally. The major strength of this approach is that growth disturbances can be recognised more rapidly, enabling corrective measures to be implemented sooner.
The major strength of [growth monitoring] is that growth disturbances can be recognised more rapidly, enabling corrective measures to be implemented sooner
Each chart includes curves, called centile lines, which represent the expected range of growth considered to be normal for dogs of a particular sex within a certain size category. Typically, you would expect a healthy puppy’s weight to stay approximately in the same part of the chart throughout growth; however, some healthy puppies track more closely to the centile lines than others. By plotting weights on the chart and tracking growth, problems can also be identified and managed more quickly; for example, puppies crossing centile lines upwards are growing quicker than expected. As well as putting the puppy at risk of becoming overweight, overly rapid growth can be associated with skeletal abnormalities such as osteochondrosis and hip dysplasia. It is possible for healthy growing dogs to cross two or more centiles in the same direction, but this is relatively uncommon. In contrast, about 60 percent and 70 percent of dogs that become overweight and obese, respectively, cross two or more centiles. Therefore, crossing centiles upwards should be a flag to a veterinary professional to check the health status of the puppy, review the nutrition plan and consider if specific investigations are required. Puppies crossing centiles downwards, on the other hand, are growing more slowly than expected. While such centile crossing can occur in healthy dogs, it is more likely to occur when there is a problem with nutrition or development.
As a dog’s growth plateaus and they reach their adult size and weight, care must be taken to reduce the amount they are being fed to maintenance levels rather than for growth to avoid excess weight gain.
It seems likely that instead of affecting metabolic rate, neutering increases the risk of obesity through the reduction in energy requirement
Neutering is another important milestone for assessing food amounts. Neutered dogs and bitches are more than twice as likely to be obese as sexually intact animals, but evidence has indicated that when metabolic rate is expressed on a lean body mass basis, rather than per total body weight, there is no difference between neutered and sexually intact individuals (German, 2006). This is important because fat stores, which make up the difference between total and lean body masses, are metabolically inactive and if they are included in the calculation of overall metabolic rate will give erroneously lower rates in fatter animals. It seems likely that instead of affecting metabolic rate, neutering increases the risk of obesity through the reduction in energy requirement – predominantly because of reduced physical activity – and changes in feeding behaviour and food consumption. The result is that energy intake exceeds energy expenditure leading to weight gain.
As dogs age they become more sedentary and conditions such as osteoarthritis can make strenuous exercise challenging or even inappropriate. If a senior dog’s diet isn’t adapted accordingly, undesirable weight gain may occur, which, in turn, can worsen the pain of osteoarthritis. This means it is crucial to keep a close eye on body condition during the senior years. As muscle mass is lost, weight may also decrease, but less muscle means less metabolically active tissue, so calorie needs may be reduced. Regular weighing and body condition scoring are key to spotting issues early during the senior life stage.
Regular weighing and body condition scoring are key to spotting issues early during the senior life stage
Maintaining a healthy body weight in dogs involves a lifelong partnership between the owner and the veterinary team. Preventing excess weight gain at any stage of life is preferable to having to embark on a weight loss plan further down the line. Regular weighing – especially during the growth phase – and monitoring of body condition are vital to spotting weight gain early and adjusting calorie intake accordingly.