Excess weight is the most common — and most overlooked — health problem in pets. Because it creeps up slowly, it is hard to notice. That is exactly why regular measurement is valuable.
Why it matters so much
Excess weight is not a single problem; it is the beginning of many. Joint pain and hip or knee trouble, diabetes risk, strain on the heart and lungs, fatty liver disease and increased risk under anaesthesia are all directly linked to weight. Rapid weight loss in cats carries a separate danger: a cat that stops eating can develop hepatic lipidosis (fatty liver disease).
Body condition score (BCS)
Weight alone does not tell you enough; 12 kg is ideal for one dog and excessive for another. Vets therefore use a body condition score from 1 to 9. The ideal range is 4–5.
| Score | Appearance |
|---|---|
| 1–3 | Ribs, spine and hip bones clearly visible. Muscle loss present. Underweight. |
| 4–5 | Ribs felt without pressing, not visible. Waistline clear when viewed from above. Ideal. |
| 6–7 | You have to press to feel the ribs. Waistline blurred. Overweight. |
| 8–9 | Ribs cannot be felt. Belly sagging, no waistline. Obese. |
Two simple checks at home
- Rib check: place your palm flat against the side. You should feel the ribs much as you feel the bones on the back of your own hand — if you have to press, there is excess weight.
- From above and from the side: viewed from above there should be an inward tuck at the waist; viewed from the side, the belly should rise up from the level of the chest.
How often should you weigh?
| Situation | Frequency |
|---|---|
| Puppy or kitten (growth phase) | Every 2 weeks |
| Healthy adult | Monthly |
| On a weight-loss programme | Weekly |
| Senior or with a chronic condition | Every 2 weeks |
Weigh under the same conditions each time: same scale, same time of day, ideally in the morning before food. For small animals, weigh yourself first, then again holding them, and take the difference.
Why recording matters: a single measurement tells you nothing; the trend does. Weight tracking in the PATI app plots your measurements on a chart and alerts you to sudden changes.
When is weight change a warning sign?
These situations point to health rather than diet:
- Losing more than 10% of body weight without dieting
- Noticeable thinning in a cat over a few weeks
- Weight loss with a normal appetite — possibly parasites, thyroid disease, diabetes or a digestive problem
- Weight gain accompanied by abdominal swelling — possibly fluid accumulation
- Weight loss alongside excessive drinking and frequent urination
In these cases, see a vet before adjusting the food.
The right pace for losing weight
Rapid weight loss is not healthy. A safe target is 1–2% of body weight per week. To achieve it:
- Give the daily amount by weight, not by eye
- Cap treats at 10% of daily calories and subtract the equivalent from meals
- Cut out table scraps entirely
- Increase exercise gradually — suddenly making an overweight animal run long distances damages the joints
- Ask your vet about therapeutic weight-loss diets
Cats must never be put on a sudden, severe restriction; a cat that stops eating risks fatty liver disease. Feline diets must always be planned under veterinary supervision.
Being underweight is also a problem
Failure to gain weight can stem from a parasite burden, dental pain preventing eating, malabsorption, kidney disease or simply insufficient calories. Increasing the portion alone can mask the underlying cause. Keeping your measurements and appetite observations on record helps your vet find the right direction faster.
🐾 Track it with PATI: You do not have to keep the schedule, measurements and reminders in this article by hand — the PATI app keeps your pet's records and tells you when it is time. Download on the App Store →
⚠️ Please note: This article is for general information and does not replace a veterinary examination. For dosage, product and treatment decisions specific to your pet, consult your veterinarian.