Symptom: Weight Gain – Why is my pet gaining weight?
Understanding a pet head tilt
The cute tilt (normal): a quick, temporary tilt of the head when hearing a new sound, showing they're listening or trying to understand you.
The medical tilt (abnormal):
Persistent angle of head held at a constant, unnatural angle to one side.
Balance issues such as circling, leaning to one side, falling, stumbling, or difficulty walking
Rapid, involuntary eye movements (nystagmus), drooping eyelids, or unequal pupil size
Other signs such as head shaking, loss of appetite, nausea, lethargy, or behavioural changes
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