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You run your hand along your dog’s flank and there it is: padding where ribs used to be. The waist has gone straight. The jump onto the sofa now takes two attempts. Weight creeps on about 200 grams at a time, and by the time most owners spot it, their dog is carrying 15 to 20 percent more body weight than their frame was built for.
Dogs do lose weight well. They just need the process handled more carefully than a human diet, because a dog cannot portion out their own meals, cannot skip a snack, and cannot tell you their knees hurt more than usual. Here is how to do it properly.
Why the Extra Kilos Matter
Vets estimate that more than half of pet dogs are overweight or obese. That is not just a cosmetic issue. Excess fat tissue is metabolically active and drives low-grade inflammation, which makes everything from arthritis to skin disease worse. Overweight dogs face higher risks of cruciate ligament rupture, diabetes, pancreatitis, breathing difficulties under anaesthetic, and heat stroke in summer.
The lifespan data is striking. A long-term study of Labrador retrievers found that dogs kept at a lean body condition lived a median of 12.9 years, compared with 11.2 years for littermates allowed to eat freely. That is nearly two extra years from portion control alone.
Rule Out a Medical Cause First
Before you change a single meal, book a vet appointment. A small but real proportion of overweight dogs have an underlying reason: hypothyroidism, Cushing’s disease, or side effects from steroid medication. These need treating, and no amount of portion control will fix them.
Ask your vet to record an official weight and a body condition score on a nine-point scale (4 or 5 out of 9 is ideal). That gives you a starting line and a target. It also means your dog gets weighed on the same calibrated scale each visit instead of your bathroom scale at home, which may be off by half a kilo.
Find the True Target Weight
Owners often aim too high. A 32 kg Labrador whose frame should carry 26 kg does not need to lose 2 kg and call it done. Ask your vet to estimate the ideal weight based on body condition, breed and build, then plan for a loss of 1 to 2 percent of current body weight per week. For a 32 kg dog, that is 320 to 640 grams a week, or roughly 1.5 to 2.5 kg a month. Faster than that risks muscle loss and gall bladder problems.
If the total loss needed is large, break it into stages. Getting 10 percent of body weight off often improves mobility enough that the next stage becomes easier.
Do the Calorie Maths, Then Weigh the Food
Guessing at portions is where most diets fail. A heaped cup of kibble can vary by 30 percent depending on the brand, the scoop and how settled the food is in the bag. Buy a cheap digital kitchen scale and weigh meals in grams.
Your vet can calculate an exact daily allowance, but the standard formula is useful to understand. Resting energy requirement is roughly 70 multiplied by the dog’s body weight in kilograms to the power of 0.75. For a dog whose ideal weight is 17 kg, that comes to about 586 kcal. For weight loss, feed around 80 percent of that figure, so roughly 470 kcal a day.
One practical warning: simply cutting back a normal adult dog food reduces vitamins and minerals along with the calories. If your dog needs a significant reduction, a therapeutic weight-loss diet is formulated to stay nutritionally complete at smaller volumes and higher protein, which helps preserve muscle.
Treats Are Usually the Hidden Half of the Problem
A single medium dog biscuit is roughly 40 to 50 kcal. Three a day is 150 kcal, which could be a third of a small dog’s entire daily allowance. Keep treats to no more than 10 percent of daily calories and count them in the total, not on top of it.
Low-calorie swaps that still feel like a reward:
- Green beans, cucumber batons or courgette slices (a handful is under 10 kcal)
- Plain cooked chicken breast, cut into pea-sized pieces
- A few pieces of their normal kibble, taken from the day’s allowance
- Carrot sticks for chewers who need something to crunch
- An ice cube or a lick of plain frozen yoghurt in hot weather
Also watch the invisible calories: licking plates, finishing the cat’s bowl, the toast crusts from a toddler, and dental chews, some of which hit 100 kcal each.
Make the Food Last Longer
Hunger is the main reason owners abandon a diet. Splitting the daily ration into three or four smaller meals genuinely helps, and a slow feeder bowl or a snuffle mat turns four minutes of eating into fifteen. Scatter feeding part of the ration across the lawn gives a dog something to do with their nose instead of standing by the bowl looking hopeful.
Build Exercise Gradually
An overweight dog cannot suddenly run 5 km. Start with an extra 5 minutes on one walk, hold it for a week, then add another 5. Aim for 20 to 40 minutes of low-impact walking twice a day for most healthy dogs, with off-lead sniffing time included because mental work tires a dog out too.
For dogs with sore joints, swimming or hydrotherapy is excellent because it removes load from the limbs. Avoid ball throwing on hard ground, long stair climbs, and pavement that is hot enough to burn your own hand. Keep exercise steady rather than dramatic. Two slow walks a day beats one heroic weekend hike that leaves the dog lame on Monday.
Get the Whole Household on Board
Most stalled diets are not caused by metabolism. They are caused by a partner who gives biscuits at 6pm, or a child who shares their snacks. Put a simple chart on the fridge with the daily allowance ticked off, and keep one person responsible for the main meals. Feed resident pets separately if one is on a diet and the other is not, and lift the cat’s bowl onto a surface the dog cannot reach.
Weigh Weekly and Adjust
Pick one day a week and weigh at the same time, ideally before breakfast. Log the number. Expect 300 to 600 grams a week for a medium-sized dog; anything more than 2 percent of body weight per week is too fast. After four weeks, if the numbers have not moved, reduce the daily ration by about 10 percent rather than cutting treats entirely, which tends to backfire.
When Progress Stalls
Plateaus are normal and usually mean the allowance has drifted upward through extra nibbles nobody counted. Go back to weighing the food with a scale for a week and recheck the treat tally. If your dog is genuinely barely eating and still not losing weight, return to the vet, since thyroid testing and an accurate body condition score may change the plan.
Once your dog reaches their target weight, do not return to the old portions. Maintenance calories sit somewhere between the weight-loss allowance and what they used to eat, often around 10 to 20 percent above the diet level. Weigh food for another month at that level until the new portion becomes automatic, then keep the weekly weigh-in going. Dogs regain weight quickly when vigilance slips, and a monthly weigh-in is a five-minute job that protects the knees, the heart and the years you get together.
