Being overweight (obesity)
Being overweight is one of the most common health problems in pets, with vets estimating that nearly half of UK dogs are overweight. Extra weight raises the risk of arthritis, diabetes, breathing problems and heatstroke, and can shorten life. Weight loss should be slow and planned with your vet.
Go to a vet now if
- An overweight cat that has stopped eating.
- Breathing difficulty or collapse in an overweight pet, especially in heat.
- Sudden weakness, collapse or vomiting in an overweight diabetic pet.
What you might notice
- You cannot easily feel the ribs under a light touch.
- No visible waist when looking from above.
- The belly hangs down instead of tucking up.
- Fat pads at the base of the tail or over the hips.
- Tiring quickly or panting more on walks.
Common causes
- Feeding more calories than the pet uses.
- Too many treats and table scraps.
- Too little exercise or play.
- Neutering and age, which lower energy needs.
- Occasionally an illness, such as a hormone problem.
What you can do at home
- Weigh food with scales instead of guessing.
- Feed for your pet's ideal weight, not its current weight.
- Cut back treats and count them as part of the daily food.
- Increase daily walks or play to suit your pet's age and health.
- Split a cat's daily food into several small meals.
Book a vet in the next day or two if
- You are unsure whether your pet is overweight.
- Your pet is gaining weight without eating more.
- Weight gain with tiredness, coat changes or more thirst.
- You need a safe weight-loss plan.
Don't
- Never put a cat on a crash diet or let it go without food; it can cause serious liver disease.
- Do not cut food drastically without a vet plan.
- Do not feed human leftovers as treats.
Prevention
- Check body shape monthly using a body condition score chart.
- Adjust portions after neutering and as your pet ages.
- Keep treats to a small part of daily food.
- Weigh your pet regularly; many practices run free weight clinics.
This guide gives general information about common health problems in dogs and cats. It is not a diagnosis and it does not replace an examination by a veterinarian. Every animal is different, and signs that look mild can sometimes hide a serious problem, especially in cats, which often hide illness and pain. If you are worried about your pet, or if your pet shows any of the warning signs listed here, contact your vet or the nearest emergency veterinary clinic straight away. Never give your pet human medicines or any medicine not prescribed for that animal by a vet.
Sources
Sources
- PDSA – Obesity in dogs
- PDSA – Obesity in cats (factsheet)
- WSAVA – Global Nutrition Guidelines and body condition score tools
- Cornell Feline Health Center – Hepatic Lipidosis
Checked against these sources in October 2026.