Most people would acknowledge that obesity would be expected to come with risks to health and every owner would want to keep their dogs healthy.

One of the problems is illustrated in the PDSA PAWS report 2023 (the full report can be found here)

In this annual report 81% of owners surveyed considered their dog to be at its ideal weight, whereas when asked, veterinary surgeons in both the UK and the US report that almost 50% of the dogs they encounter are overweight or obese.

A dog is considered to be obese when its body weight is 20% above the ideal. (For a 30kg labrador that would be 36Kg)

It might be better to consider the problem to be weight gain once growth is complete rather than obesity which is the outcome. 

One of the factors that surprises many owners is how early in life their dog becomes fully grown. In small breeds this will be by 12 months of age and even in giant breeds they have usually finished growing by 15-16m of age.

Once a dog has reached its adult size its weight should ideally remain static.

It is continuing to gain weight beyond reaching adult body size that leads ultimately to obesity and all the health concerns that entails.

For example a 30kg labrador that only gained 2% body weight each year (that is 600g or 1lb 5oz) would be obese by the time it was 10 yrs old.

Weight gain comes about when more calories are consumed than are burned off in normal daily activities. Several things will influence the amount of calories burned but obviously exercise is a very significant factor.

So in feeding any dog the aim is to provide a healthy balanced diet that provides just the right amount of energy for its level of activity resulting in a stable ideal body weight.

As we could see earlier, almost half of dog owners do not achieve this balance.

Feeding guides

Many owners will rely on feeding guides that come with the food they chose to buy but these are very rough guides and it is critical that weight or body condition score is continually monitored. It is better that an independent person such as a vet nurse or vet assesses condition scores as owners may be inclined to misread them (see above where approximately 80% of owners consider their pets to be ideal weight) 

It is important to remember that a dog's diet is EVERYTHING it eats, the food in its bowl but also all the treats and leftovers that you or others may give them plus anything they may find on their own.

Dogs allowed to feed ad.lib. (that is food is always available) will frequently over eat.

Many dogs that owners consider to be fussy eaters because they sometimes leave their food are actually just over full. In these cases owners often add attractive components to the diet to encourage eating which just makes matters worse.

Older dogs will invariably begin to slow down and exercise less but owners don’t always reduce their feeding to allow for this leading to increased weight gain at the worst time of life.

Sometimes owners are forced to change their routine, for example, through injury or change of work patterns and this may mean less exercise for the dog, obviously it is important to reduce feeding accordingly.

Purely increasing exercise in order to control weight is rarely successful, do more, eat less is the simple mantra and it works!

Weighing the dog

Body weight is relatively easy to monitor at home for small dogs and you should ask your vet to record your dog’s weight at every visit (many will anyway). Large dogs can be weighed at a veterinary surgery but if for any reason you cannot weigh your dog there is another way to check if they are gaining weight.

Take a soft tape measure and place it round the narrowest part of your dog's tummy just in front of the hind legs. The tape should not be pulled tight but you should get one finger under it comfortably, if that measurement is increasing so is your dog's weight!

The PDSA pet health hub has lots of useful advice on feeding exercise and obesity and can be found here

Consequences of increasing body weight and obesity.

Shortened lifespan

Increased joint and back pain

Knee ligament injuries (often requiring surgery)

Increased risk of diabetes and insulin resistance making diabetes harder to control

Incontinence (urinary leakage)

Breathing difficulties (worse still in flat faced dogs)

Some forms of cancer 

Heatstroke (More dogs die of heatstroke whilst exercising than in hot cars)

Injury

Skin fold infections

Foot problems

Increased medical/surgical costs

Increased anaesthetic and surgical risk

Unnecessarily high cost of feeding

On top of this some conditions will be harder to treat, for instance heart disease will cause problems earlier in overweight dogs and will require more medication and therefore be more costly to treat. They will also reach a stage where treatment is no longer effective at an earlier stage.

In general terms it might be best to just consider that increasing weight beyond the ideal speeds up the ageing process. Research has shown that dogs that maintain a healthy body weight may live 2 years longer than their obese counterparts and possibly more importantly their quality of life is likely to be better over that time.

If you are aware that your dog is overweight or gaining weight it is worth a visit to your veterinary practice, many will run weight clinics because it is such a common problem but also because there are some underlying medical conditions, for instance, low thyroid hormone (hypothyroidism) or cushing's disease (hyperadrenocorticism) that may have weight gain as a feature and your vet may want to check for these.

There are several very good diets now manufactured specifically to aid weight control that your veterinary practice is best placed to advise you about.

It is increasingly understood that weight control in pets is a very complex problem that involves human behaviour change in many cases and that is a science in itself.

We should think of weight control as a therapy, a tonic if you will, for an active and healthy pet in later life, that way it loses the feeling of being mean. It works for people and it works for pets.