Your vet has just told you your dog is overweight — or you've noticed the extra padding yourself. What now? The good news is that even modest weight loss makes a significant difference to a dog's joint health, energy, and longevity. The challenge is doing it safely and consistently.
First: Rule Out Medical Causes
Before changing diet, ask your vet to check for hypothyroidism (underactive thyroid) and Cushing's disease (excess cortisol production). Both cause weight gain that won't respond to diet changes until the underlying condition is treated. These are more common than many owners realise — especially in middle-aged and older dogs.
Calculate How Much Your Dog Should Eat
Most owners either guess portion sizes or follow the bag guide — which is often calibrated for an active, ideal-weight dog, not a sedentary overweight one. A better starting point:
- Find out your dog's ideal weight (ask your vet, or check breed standards as a reference).
- Calculate their Resting Energy Requirement (RER) at ideal weight: RER (kcal/day) = 70 × (ideal weight in kg)^0.75
- For weight loss in a neutered adult: multiply RER by 1.0 (not the standard 1.6 maintenance factor).
- Choose a food and check its caloric density per 100g. Divide to find the daily gram target.
This sounds complicated, but most vets can do this calculation at a weight check appointment. Ask for a written feeding plan.
Reduce Treats — This Is Usually the Biggest Factor
Studies consistently show that owners dramatically underestimate the caloric contribution of treats. A single Bonio biscuit contains around 70 kcal. For a 10 kg dog needing 400 kcal/day, three biscuits is 52% of their daily intake — on top of meals. Low-calorie treat alternatives: carrot sticks, cucumber, a small piece of cooked chicken, blueberries. These work just as well for positive reinforcement training.
Exercise: Increase Gradually
Sudden big exercise increases for an overweight dog risk joint injury, especially in breeds prone to hip or elbow problems (Labradors, German Shepherds, Goldens). A safer approach:
- Increase current walk duration by 10% per week.
- Add a second short walk rather than doubling one walk.
- Swimming and hydrotherapy are excellent low-impact options for dogs with joint issues.
- Mental enrichment (sniff walks, training sessions, puzzle feeders) burns calories and is often easier on joints than forced physical exercise.
How Fast Should Your Dog Lose Weight?
Safe weight loss for dogs is typically 1–2% of body weight per week. For a 20 kg dog, that's 200–400g per week. Faster than this risks muscle loss rather than fat loss. Slower is fine — consistent is what matters.
Weigh Monthly and Track the Trend
Weight loss is not linear. There will be weeks with no movement and weeks with more. What you need is the trend over 8–12 weeks, not the number on any given day. Weigh your dog at the same time of day, on the same scales, after a similar amount of time since their last meal.
Woofio's weight tracker logs each entry, shows the trend line, and compares it against your dog's breed ideal range — so you can see at a glance whether the plan is working.