Dog Not Losing Weight? A Troubleshooting Guide

Quick answer When a dog is not losing weight, check the usual causes first: food measured by cup instead of grams, uncounted treats and table scraps, a scale that is inconsistent and a plan that has not been recalculated. If everything is accounted for for two to three weeks, ask your vet to review the plan and rule out medical causes.

You have measured the food, cut the biscuits and walked a little more, and yet the number on the scale will not budge. It is frustrating, and it is common. In most cases, the reason is something small and fixable: a cup that holds more than you think, a treat nobody counted, a scale that jumps around. In a minority of cases there is a medical reason, which only your vet can find. This guide gives you a methodical checklist, in the order that tends to find the problem fastest, so that you can fix what you can and know when to ask for help.

First, is it really a plateau?

Weight moves in small steps and day-to-day readings fluctuate with food, water and toileting. A dog’s weight can differ by a few hundred grams between mornings. So before deciding that nothing is working, look at the trend.

Check	What to do
Time frame	Compare weights two to three weeks apart, not day to day
Same conditions	Same scale, same time, before breakfast
Averages	Average two weigh-ins in each week
Photos	Compare side and top photos month to month
Body condition	Re-score with the Dog Body Condition Score tool

If the trend is flat or rising after two to three weeks of careful weighing, work through the rest of the list. A dog losing 1% a week from 20 kg loses about 200 g, which is smaller than normal scale noise, so use the longer window.

Cause 1: the food is not measured accurately

Measuring by cup is the single most common problem. A cup of kibble can vary by 10 to 20% in weight depending on the scoop and how it is filled, and over a month that is a lot of food. Weigh the daily amount on a kitchen scale in grams. Use the Dog Food Cups to Grams Calculator if you only know the cups on the label, and then check with a scale. Also check that the energy value you are using matches the food in the bowl; a different brand can have 10% more calories per gram.

Cause 2: treats, chews and extras

Treats are the next suspect. Count everything: training rewards, dental chews, rawhide, bits of cheese, toast crusts, the spoonful of leftovers and anything licked off plates. A single 30 kcal biscuit is about 5% of the daily allowance for a 16 kg dog on a weight-loss plan of 560 kcal. A few of those a day undo the deficit. Keep a notepad on the fridge, and tick every extra. Treats should stay within 10% of the daily calories, and the meals should shrink to match. Our guide to training treats without weight gain shows how.

Cause 3: other people feeding the dog

In many households, the person who counts the food is not the only person who feeds the dog. Children, partners, neighbours and walkers can all add calories. Talk to everyone, explain the plan and agree on a treat jar that is filled each morning. Ask walkers and dog-sitters not to give extras. The dog’s behaviour can also give hints: a dog that is “always starving” at your feet but “not eating enough” may be getting snacks elsewhere.

Cause 4: the target is too high or has not been updated

A calorie target is a starting point. The calculator sets weight-loss calories using the ideal weight (1.0 times resting energy at the goal weight), but individual dogs differ, and the target should be revisited as weight falls. Check that you are using the right goal weight, that you have recalculated after the first few kilograms and that your vet agrees the target suits your dog. The Dog Weight Loss Calculator lets you re-enter the new current weight, and our calories for dog weight loss guide shows the arithmetic.

Cause 5: the scale

A wobbly scale makes a plateau look worse than it is. Test yours with an object of known weight. For large dogs weighed on a bathroom scale, subtracting your own weight adds error: both readings have rounding. Use a vet’s scale every few weeks as the benchmark, since many practices allow free weigh-ins. Always compare like with like.

Cause 6: activity has dropped

Weather, injury, a busy week or a change in routine can lower activity without being noticed. Compare the walks this month with last month. If your dog is walking less, bring activity up gradually, but check with your vet first if there is any sign of stiffness or discomfort. Our guide to exercise for an overweight dog gives a safe way to build up.

Cause 7: a medical reason

If you have eliminated the practical causes and weight has not moved after a few weeks of careful following of a vet-approved plan, ask your vet to look further. Some medical conditions and some medicines can affect weight and appetite. Only a veterinary examination, and tests if needed, can find or exclude them. Do not assume or self-diagnose. Take your records: dates, weights, food amounts and notes about treats and activity.

A troubleshooting table

Symptom	Likely cause	First step
Flat weight, sensible plan	Measuring or treats	Weigh food in grams; log everything for a week
Slow loss at first, then flat	Target not updated	Recalculate with the new weight; ask your vet
Weight goes up and down	Scale or timing	Same scale, same time; average two readings
Dog seems hungry all the time	Too few calories or low-fibre food	Ask your vet; do not cut further
Dog begging and getting scraps	Other feeders	Treat jar; talk to everyone
Weight rising despite the plan	Hidden calories or medical cause	Log; call the vet

What not to do

Do not slash calories below the vet’s target.
Do not skip meals or fast the dog.
Do not give human weight-loss products or supplements.
Do not rely on exercise alone.
Do not weigh daily and react to every change.
Do not give up after one flat week.

Keeping the plan alive

Weight loss is a long project, and motivation dips. Break it into stages of 5% of body weight, celebrate each with a non-food reward such as a new walk, and keep a visible chart. Make the plan part of the routine rather than an extra chore. The Pet Weight Change Calculator can tell you if the pace between two weights is inside the safe range.

Common mistakes

Measuring by cup.
Forgetting treats and chews.
Not telling the whole household.
Using an unreliable scale.
Cutting food further without advice.
Assuming the dog just has a “slow metabolism”.

Questions to ask your vet

Is the plan I am following right for my dog?
Could a medical condition be involved?
How often should we recheck weight?
Is the food I am using suitable for weight loss?
What exercise should I add?

A one-week audit you can do yourself

If you suspect that something is going wrong, run a one-week audit.

Day	What to do
1	Weigh the dog; weigh the daily food in grams; write down the food’s kcal per gram
2 to 6	Write down every treat, chew and scrap, with weights where you can
7	Add up the week’s calories from meals and extras; compare with the target

Compare the total with the target. If the total is above, you have found the leak. For example, a 16 kg dog on a 560 kcal target eating 700 kcal a day has a surplus of 140 kcal, the equivalent of about four small biscuits a day, and no weight will come off. If the total matches and the dog is still not losing, take your log to the vet.

Hunger and begging

A hungry dog is a challenge for any owner. Ideas that may help, all within the calorie target: split the day’s food into more meals, use puzzle feeders or scatter feeding, add low-calorie bulk such as suitable vegetables if your vet approves, and walk or play at the times your dog usually begs. Ask your vet about a weight-management food, which is designed to be satisfying at lower calories. Do not give in to begging with extras, since each lapse teaches the dog that begging works.

Understanding energy balance without the jargon

A dog loses weight only if it takes in fewer calories than it uses, over weeks. The surplus or deficit is the difference between the two. A 20 kg dog using about 1,059 kcal a day that eats 1,100 has a small surplus of 41 kcal, and will drift up slowly. A dog on a weight-loss plan of 560 kcal that is fed 700 has a surplus relative to the plan of 140, so loss stalls. Small gaps matter because they are repeated every day. This is why the audit in this guide asks you to count everything.

What a vet visit for a stalled diet looks like

Expect questions about food, treats, exercise and routine, and bring your log. The vet will weigh the dog, check body condition and may examine the dog for signs of conditions that affect weight. They may suggest blood tests. They may adjust the calorie target, change the food to one designed for weight loss, suggest more structured exercise or refer you to a nurse clinic for regular weigh-ins. The visit is not a verdict on you; vets see stalled diets all the time, and they usually find that small changes in routine get things moving.

Staying motivated through a plateau

Plateaus are demoralising. Look at the whole graph and the earlier losses, take photos, and celebrate non-scale wins such as more energy, easier walks and a visible waist. Share progress with friends or a clinic group. Keep the plan simple and consistent, and set a short-term goal, such as one more good week. The Pet Weight Goal Date Calculator can reset your target date.

A final checklist

Weigh food in grams and confirm the energy value.
Log every treat and chew for a week.
Check the scale and weigh at the same time.
Involve the household and walkers.
Recalculate the target with your vet.
Review activity and add gentle exercise.
Book a vet check if all else is in order and weight is flat after a few weeks.

Quick summary

Check the trend over two to three weeks before deciding it is a plateau.
Weigh food in grams, count every treat and involve the whole household.
Recalculate the target as weight falls and confirm it with your vet.
Check the scale, activity and body condition.
If all is in order and weight is flat, ask your vet to rule out medical causes.
Use the Dog Weight Loss Calculator to reset the plan.

Frequently asked questions

Why is my dog not losing weight on a diet?

The most common reasons are measuring errors, extra treats or scraps, an inconsistent scale and a calorie target that has not been updated.

How long should I wait before worrying?

Weights fluctuate week to week. If there is no downward trend over two to three weeks of accurate measuring, talk to your vet.

Could a medical condition stop weight loss?

Some conditions affect weight and appetite. Only a vet can assess this, so ask for a review if the plan is followed carefully and the dog is not losing.

Should I cut my dog's food further?

Not without your vet. Cutting too far risks missing nutrients and muscle loss.

Can too little food slow weight loss?

Extreme cuts are not recommended. The right amount is the one your vet sets for your dog.

How do I check my scale?

Weigh a known object, such as a packet of flour or a dumbbell, and compare. Use the same scale each time.

What about exercise?

Increase gradually and safely as your vet advises. Exercise helps but food control matters more.

Sources

Reviewed by the CalcuPaw Veterinary Review Team

Last reviewed 18 Oct 2026 · Meet the review team · This guide is general information, not veterinary advice.