Obesity is one of the health conditions that dogs owners should know about, because it affects quality of life, and it is easier to manage when it is caught early. This guide explains what obesity is, the signs to watch for, what causes it, how it is diagnosed, how it is treated, whether it can be prevented, and how to live with a dog that has it. Every suggestion here is general guidance, not a prescription for an individual dog.
This guide covers obesity in dogs in full: what it is, the signs to watch for, what causes it, how it is diagnosed, how it is treated, whether it can be prevented, and how to live with a dog that has it. Every suggestion here is general guidance, not a prescription for an individual dog, and a dog with obesity should be checked by a vet, because the right treatment depends on the individual dog, its age, and how advanced the condition is.
What is obesity in dogs?
Obesity is a condition where a dog carries so much extra fat that its health is affected — not just a little extra weight, but enough fat to strain its joints, its heart, and its metabolism, and to shorten its life. A dog is usually called obese when it is more than about 20% above its ideal weight, and overweight when it is 10 to 20% above it. Obesity is the most common nutrition-related health problem in dogs, and it is also one of the most preventable: it comes from taking in more calories than the dog burns, over months and years.
The rest of this guide covers the signs, the causes, how obesity is diagnosed, how it is treated, whether it can be prevented, and how to live with a dog that has it. A dog with obesity should be checked by a vet, because the right treatment depends on the individual dog, its age, and how advanced the condition is — and because some of the signs of obesity can also be signs of other conditions, which need a vet to tell apart. The dog ideal weight calculator works out a target weight range, and the when is a dog considered a senior guide gives the senior thresholds by size.
Signs of obesity in dogs
The signs of obesity in dogs are listed below. Not every dog with obesity will show every sign, and some dogs will show only one or two — but any one of these signs, especially if it lasts more than a few days or gets worse, is worth mentioning to a vet. A dog that is bright, eating, drinking, and otherwise well between episodes is less likely to be seriously ill than a dog that is lethargic, off its food, or losing weight — but the only way to know is to check.
- You cannot feel the ribs easily — you have to press hard to find them under a layer of fat.
- There is no waist when you look down at the dog from above.
- There is no tummy tuck when you look from the side — the belly hangs low or sags.
- The dog tires easily on walks or in play, and pants more than it used to.
- The dog struggles to jump, climb stairs, or get up after lying down.
- The collar or harness needs letting out, or the dog has outgrown it.
- The dog begs for food constantly, and is always looking for more.
If two or more of those signs apply, or if one sign is severe — a dog that cannot urinate, cannot breathe, cannot stand, or has had a seizure lasting more than five minutes — see a vet the same day. Those are signs that need a vet, not waiting. Bring a note of when the signs started, how often they happen, and what the dog eats and drinks — that information helps the vet far more than a guess about the cause. The how to tell if your dog is overweight guide gives the hands-on check for weight, which matters for many of these conditions.
Causes and risk factors for obesity
Obesity usually comes from the same two causes: too much food and too little exercise. Treats, table scraps, and food from other pets' bowls add up fast, and a dog that is fed by eye rather than by measure is almost always fed too much. Neutering cuts calorie needs by about 10 to 20%, and a dog whose food is not cut after the operation will gain weight. Age matters too: an older dog moves less but often eats the same amount, so weight creeps up. Some breeds gain weight more easily, and some medical conditions, such as an underactive thyroid in dogs, cause weight gain — but food and exercise are the main causes in most dogs.
Some dogs are more prone to obesity than others, because of their genes, their breed, their size, or their age — but breed and age are not destiny, and a dog of any breed can develop obesity. What an owner can control is weight, food, exercise, and vet checks: a dog at a healthy weight, with measured food and daily exercise, is less likely to develop obesity and will cope better with it if it does. A dog that is overweight, that eats a poor diet, or that never sees a vet is more likely to develop obesity and to have it found late, when it is harder to treat.
How obesity is diagnosed
A vet diagnoses obesity with a weigh-in and a body condition score, on the nine-point scale where 4 to 5 is ideal and 8 to 9 is obese. The vet will feel the ribs, look for a waist from above and a tummy tuck from the side, and compare the weight with the breed's typical range. The vet may also run a blood test, because some medical conditions cause weight gain, and those need treating, not just less food. A dog that is obese should have a plan set with its vet, because a crash diet is dangerous — especially for cats.
If you are worried about your dog, see a vet and mention obesity by name, with the signs you have seen and when they started. Bring a note of what the dog eats, how much, and any medicines it takes, and whether it has had obesity or a related condition before. A video of the signs, if it is safe to take one, helps the vet far more than a description — especially for seizures, limping, or breathing problems. Do not try to diagnose obesity yourself, and do not buy medicines or special diets for it without veterinary advice, because the wrong treatment can make it worse.
Treatment and management of obesity
Treatment is slow, steady weight loss: measured food, a little more exercise, and a monthly weigh-in. A commonly cited safe target is about 1% of body weight per month for dogs and about half a percent to 1% for cats. A weight-loss food helps, because it carries fewer calories per mouthful, less fat, more fibre so the dog feels full, and enough protein to hold muscle. Treats should stay under 10% of daily calories, and exercise should build up gradually — short, frequent walks or play sessions rather than one long hike, because a heavy dog that is suddenly asked to run will strain its joints. In some cases the vet may prescribe a medicine, but food and exercise are the core of it.
Treatment is a decision made with the vet, weighing the dog's age, health, and quality of life against the treatment and its side effects. Some owners choose not to treat, and to keep the dog comfortable instead — and that is a valid choice, made with the vet, not on the basis of a web page. Whatever is decided, the treatment must be followed every day, at the same times, and the dog must be checked regularly, because obesity changes over time, and the treatment needs to change with it. Do not stop a medicine suddenly, and do not change the dose without veterinary advice.
Living with a dog with obesity
A dog that is obese can live a full and happy life once the weight comes off — and even a small weight loss, of 5 to 10% of body weight, makes a real difference to joints and health. Keep the food measured, keep treats under 10% of daily calories, keep exercise daily, and keep weighing monthly for life. A dog that has lost weight needs less food than it did before, because a lighter dog burns fewer calories, so do not go back to the old amount once the target is reached. Watch for the health problems that obesity brings — joint pain, diabetes, and heart disease — and mention any change to your vet promptly.
Keep a routine: the same times for food, medicines, walks, and play, the same places for furniture, food, and water, and a calm, predictable home. Keep a note of appetite, drinking, weight, and behaviour, and mention any change to the vet promptly — a change that lasts more than a few days, or that gets worse, is worth a vet visit. Keep the dog at a healthy weight, with measured food and daily exercise at a level that suits its body, and keep vet checks regular: once a year as an adult, and twice a year as a senior. The senior dog diet guide covers feeding older dogs, and the dog calorie calculator works out daily calories for any weight.
Can obesity be prevented?
Obesity is prevented by the same things that treat it: measured food, treats under 10% of daily calories, daily exercise, and a monthly weigh-in. Cut food by 10 to 20% after neutering, and watch the waistline for the next few months. Feed two meals a day at set times, not food left down all day, and agree in the household who feeds the dog and what treats are allowed, because a dog fed by three people is fed three times. Weigh monthly and write the number down: the line over months is what matters, and a dog that is slowly gaining weight needs a small food cut, before it becomes clearly overweight.
Early checks matter most: have the dog checked regularly, so obesity is found early, when treatment works best. Keep the dog at a healthy weight, with measured food and daily exercise, and mention any change in drinking, eating, weight, or behaviour to your vet early, because a change caught early is easier to treat than one left for weeks.
For related reading, see the dog ideal weight calculator, the dog body condition score chart, the how to tell if your dog is overweight guide, the senior dog diet guide, the dog calorie calculator, the when is a dog considered a senior guide.
Frequently asked questions
What is obesity in dogs?
Obesity is a condition where a dog carries so much extra fat that its health is affected — not just a little extra weight, but enough fat to strain its joints, its heart, and its metabolism, and to shorten its life. A dog is usually called obese when it is more than about 20% above its ideal weight, and overweight when it is 10 to 20% above it. Obesity is the most common nutrition-related health problem in dogs, and it is also one of the most preventable: it comes from taking in more calories than the dog burns, over months and years.
What are the signs of obesity in dogs?
The most common signs are: You cannot feel the ribs easily — you have to press hard to find them under a layer of fat. There is no waist when you look down at the dog from above. There is no tummy tuck when you look from the side — the belly hangs low or sags. See the full list above for every sign to watch for, and see a vet promptly if two or more apply, or if one sign is severe.
What causes obesity in dogs?
Obesity usually comes from the same two causes: too much food and too little exercise. Treats, table scraps, and food from other pets' bowls add up fast, and a dog that is fed by eye rather than by measure is almost always fed too much. Neutering cuts calorie needs by about 10 to 20%, and a dog whose food is not cut after the operation will gain weight. Age matters too: an older dog moves less but often eats the same amount, so weight creeps up. Some breeds gain weight more easily, and some medical conditions, such as an underactive thyroid in dogs, cause weight gain — but food and exercise are the main causes in most dogs.
How is obesity diagnosed?
A vet diagnoses obesity with a weigh-in and a body condition score, on the nine-point scale where 4 to 5 is ideal and 8 to 9 is obese. The vet will feel the ribs, look for a waist from above and a tummy tuck from the side, and compare the weight with the breed's typical range. The vet may also run a blood test, because some medical conditions cause weight gain, and those need treating, not just less food. A dog that is obese should have a plan set with its vet, because a crash diet is dangerous — especially for cats.
How is obesity treated?
Treatment is slow, steady weight loss: measured food, a little more exercise, and a monthly weigh-in. A commonly cited safe target is about 1% of body weight per month for dogs and about half a percent to 1% for cats. A weight-loss food helps, because it carries fewer calories per mouthful, less fat, more fibre so the dog feels full, and enough protein to hold muscle. Treats should stay under 10% of daily calories, and exercise should build up gradually — short, frequent walks or play sessions rather than one long hike, because a heavy dog that is suddenly asked to run will strain its joints. In some cases the vet may prescribe a medicine, but food and exercise are the core of it.
When should a dog with obesity see a vet?
See a vet promptly if the dog shows any of the signs above, especially if they last more than a few days or get worse — and the same day if the dog cannot urinate, cannot breathe, cannot stand, has had a seizure lasting more than five minutes, or is lethargic or off its food. Bring a note of when the signs started and what the dog eats and drinks. A dog with obesity should be checked by a vet, because the right treatment depends on the individual dog, its age, and how advanced the condition is.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.