Pet Weight Recheck
Compare two weigh-ins to see whether your pet's weight went up, down, or stayed about the same. See the trend at a glance and get an estimate of how quickly the change happened.
Enter two weigh-ins. We'll show the change at a glance and, when weight loss is planned, how the estimated rate compares with APOP's general planning range. Keep following the plan from your veterinary team. Unexpected weight loss, poor appetite, or illness should be discussed with your veterinarian.
Choose your pet and units
Enter your two weigh-ins
Earlier weigh-in
More recent weigh-in
Your results
Weight trend
This graph shows the direction of change between these two weigh-ins. It is not a forecast or a target.
See the pace calculations
Safety notes and when to contact your veterinary team
This tool compares two weigh-ins for an adult dog or cat. It does not diagnose obesity, explain the cause of weight change, prescribe calories, or confirm that weight loss is appropriate or safe.
APOP's general monthly planning ranges: about 3% to 5% for dogs and 2% to 5% for cats.
Your veterinary team may set a different pace for your pet, and their plan comes first. These are planning ranges, not safety ceilings.
Rapid-loss warning: Loss faster than 2% of body weight per week triggers an amber alert for either species. Confirm the measurement and check with your veterinarian.
Follow your pet's prescribed plan. Do not reduce food, skip meals, or change the plan based on this result alone.
- Contact the clinic promptly if weight loss is unplanned, appetite drops, or your pet seems unwell, even when the result is within the displayed range.
- A cat eating little or nothing for 24 hours needs veterinary assessment the same day. Call sooner if appetite drops. Do not wait 24 hours if the cat seems ill.
- Seek urgent veterinary care for trouble breathing, collapse, or severe weakness.
How to weigh your dog or cat for a more accurate result
For the most accurate comparison, use the same scale and similar conditions for both weigh-ins.
Home weigh-ins can vary. A different scale, a recent meal, a full bladder, a heavy collar or harness, or weighing at a different time of day can make a small change look larger than it really is.
- Use the same scale whenever possible.
- Weigh at about the same time of day.
- Weigh before a meal when possible.
- Remove heavy collars, harnesses, sweaters, or carriers unless you subtract their weight.
- For cats and small dogs, use a baby scale when available.
- If using a home scale, weigh yourself holding your pet, then subtract your weight.
- If the number seems surprising, weigh again before changing the feeding plan.
Rechecks: Weigh every 2–4 weeks during active weight loss, then as your veterinary team directs.
Monthly ranges, alert thresholds, and calculation method
The monthly planning range is not a safety ceiling. A pace above it does not automatically mean the feeding plan should change. Rates below it are not automatically a problem or a reason to reduce food.
The rapid-loss amber trigger is faster than 2% of body weight per week for either species. Red is reserved for input concerns, including implausible entries, reversed dates, and possible unit mix-ups.
Calculation: weight change (%) = (later weight minus earlier weight) ÷ earlier weight × 100. The weekly average multiplies this by 7 ÷ elapsed days. The monthly average multiplies it by 30.44 ÷ elapsed days.
The comparison uses the earlier measured weight as its reference. It is a scaled average between two weigh-ins, not a prediction of future weight loss. Estimates from less than 14 days need particular caution. Alerts use unrounded rates. Displayed numbers are rounded.