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How to Track Your Pet's Weight at Home (and Why the Trend Matters)
Last updated: 10 August 2026
Weight is the cheapest health test you'll ever run on your pet — and one of the most revealing. A slow drift up or down is often the first visible sign that something's changing, long before other symptoms show. The catch: a single number tells you almost nothing. It's the trend across months that matters. Here's how to weigh your dog or cat at home, how often, and what to do with the numbers.
How to weigh your pet at home
For a large dog, a flat pet or platform scale is easiest. For cats and small dogs, use the hold-and-subtract method:
- Weigh yourself on a bathroom scale and note the number.
- Weigh yourself holding your pet.
- Subtract the first from the second — that's your pet's weight.
A baby scale or vet scale is more precise for small animals if you have one. Whatever you use, the golden rule for a useful trend is consistency: same scale, same time of day, similar conditions each time. That removes the noise so a real change stands out.
How often to weigh
| Situation | Suggested frequency |
|---|---|
| Healthy adult, stable weight | Every 1–2 months |
| Overweight or underweight | About once a month |
| On a treatment that affects weight, or a senior pet | Monthly, or as your vet advises |
| Growing puppy or kitten | More often, to confirm healthy growth |
Weight is only half the picture — pair it with a quick body condition check (can you feel the ribs easily? is there a visible waist from above?). Weight plus body condition beats either alone.
Why the trend matters more than the number
Your pet's "ideal" weight is individual, so an isolated reading is hard to judge. A trend, though, is loud and clear. Steady or sudden weight loss can signal diabetes, thyroid, kidney, dental or digestive problems — or that a medication needs adjusting. Steady gain can point to overfeeding, reduced activity, or fluid retention. Because these shifts are gradual, you rarely notice them by eye day to day; a simple logged line over months makes them obvious while they're still easy to address.
What to log with each weigh-in
- Date and weight — the two essentials that build the trend.
- Context — diet or treat changes, a new medication, more or less exercise.
- Anything you noticed — appetite, energy, drinking more than usual.
A phone note works, but it's hard to see the trend in a list of numbers. PET-A logs weigh-ins, shows the trend at a glance, and keeps it next to your pet's medications and vet visits — and can export the whole history as a PDF or CSV to bring to your vet.
See the trend, not just the number
PET-A tracks weight over time alongside meds and vet visits, and exports a clean history for your vet. Free for one pet.
Frequently asked questions
How do I weigh my cat or small dog at home?
Weigh yourself, then weigh yourself holding your pet, and subtract the difference. Use the same scale at the same time of day for a reliable trend. A baby or pet scale is even more precise for small animals.
How often should I weigh my pet?
Every 1–2 months if they're at a healthy weight; about monthly if they're over/underweight or on a treatment that affects weight, or as your vet advises.
Why does the trend matter more than a single number?
One weigh-in is a snapshot. A trend across several can reveal steady gain or loss early — often the first sign of conditions like diabetes, thyroid or kidney disease — before other symptoms appear.
What should I record with each weigh-in?
The date and weight, plus context like diet, treat, medication or activity changes. That helps you and your vet interpret the trend.