Symptom: Weight Gain – Why is my pet gaining weight?
How can I recognise if my pet is putting on weight?
Loss of waistline
Difficulty feeling ribs
Visible fat deposits
Less active and show a decreased interest in play or walks and difficulties moving
Increased panting
Sleeping more
Changes in coat and skin
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published October 2025 | Review date October 2028 | This advice is for UK pets only and is not a replacement for seeing a vet
Frequently asked questions
What are the common reasons for my pet putting on weight?
- Diet: overfeeding, feeding the wrong food, high calories or processed food
More reading: Age Appropriate Nutrition for Dogs
- Lack of exercise: sedentary lifestyle, boredom
- Medical conditions: for example, an underactive thyroid, Cushing's disease.
- Hormonal changes: spaying/neutering, ageing
- Certain medications, for example, steroids
DOs - My pet is gaining weight, what to do at home:
- Do use a commercial weight-control diet
- Do measure food accurately
- Do limit treats
- Do add water to your pet’s meal
- Do ensure your pet exercises
DON'Ts - My pet is gaining weight, what not to do at home:
- Don’t starve your pet
- Don't feed table scraps or human food
- Don't guess at portion sizes
- Don't assume all food is equal
- Don’t abruptly change his/her diet or exercise
- Don't over-exercise if your pet is not used to it
When should I think about going to the vet if my pet is gaining weight?
- Rapid unexplained weight gain
- If your pet has started new medications, weight gain may be a reaction
- Pet recently finding it hard to be active
- Difficulty breathing or shortness of breath associated with weight gain
- Swollen belly
- Lethargy and weakness and not eating despite weight gain