How Fast Should a Dog Lose Weight? Safe Rate and Timeline

How fast should a dog lose weight? Veterinary guidelines from the American Animal Hospital Association (AAHA) give a clear answer: about 1–2% of body weight per week. That sounds slow, but it adds up. A dog that needs to lose 10% of its weight will usually get there in 10 to 20 weeks, and a slow, steady loss is far more likely to be fat rather than muscle, and far more likely to stay off.

Below you’ll find a weekly weight loss chart by size, a worked example using our dog weight loss calculator, how to adjust the plan every two weeks, and the signs that mean you should slow down or call your vet.

What is a safe rate of weight loss for a dog?

The 2014 AAHA Weight Management Guidelines recommend a target of 1–2% of body weight per week for dogs. Cornell University’s Riney Canine Health Center uses the same range and gives a simple example: a 50 lb dog should lose about ½ to 1 lb a week.

VCA Animal Hospitals adds a useful detail: for dogs that are severely obese, a rate closer to 0.5% a week is often more appropriate. Rapid weight loss can mean losing lean muscle along with fat, and muscle is exactly what an overweight dog needs to keep.

The Association for Pet Obesity Prevention (APOP) suggests planning around 3–5% a month, which sits at the gentle end of the same range.

Dog weight loss per week: chart by weight

This chart shows 1–2% of body weight per week, which is the same range our calculator uses.

Dog’s current weight	Safe loss per week	Safe loss per month (about)
20 lb	0.2–0.4 lb	0.8–1.6 lb
30 lb	0.3–0.6 lb	1.2–2.4 lb
50 lb	0.5–1.0 lb	2–4 lb
70 lb	0.7–1.4 lb	2.8–5.6 lb
90 lb	0.9–1.8 lb	3.6–7.2 lb

For small dogs, those weekly numbers are tiny. A 20 lb dog losing a quarter of a pound a week is right on track, which is why a scale that reads to a tenth of a pound (or weighing at the vet clinic) makes a big difference.

How much weight does my dog need to lose?

Vets use a body condition score (BCS) to judge this, most often on a 9-point scale. A score of 4 or 5 is ideal. You should be able to feel the ribs easily under a thin layer of fat, and see a waist from above. The WSAVA publishes free body condition charts with pictures.

A rule of thumb from the AAHA guidelines: each point above 5 means roughly 10% over ideal weight.

• BCS 6: about 10% overweight
• BCS 7: about 20% overweight
• BCS 8: about 30% overweight
• BCS 9: about 40% or more overweight

AAHA’s own example is a 45 kg (99 lb) Labrador at BCS 8, which is about 30% overweight. The math works backward: ideal weight = current weight ÷ (1 + 0.1 × points above 5).

Worked example: a 60 lb dog at BCS 7

Here’s how our dog weight loss calculator builds a plan for a 60 lb dog with a body condition score of 7 out of 9:

1. Find the ideal weight. BCS 7 is two points above 5, so about 20% over. 60 ÷ 1.2 = 50 lb. That’s 10 lb to lose.
2. Set a safe weekly rate. 1–2% of 60 lb is 0.6–1.2 lb a week.
3. Estimate the timeline. At 2% a week the dog reaches 50 lb in about 10 weeks. At 1% a week it takes about 19 weeks.
4. Set the calories. The calculator uses the resting energy requirement (RER) at the ideal weight: 70 × (22.7 kg)^0.75 ≈ 727 kcal a day. It also shows 582 kcal (0.8 × RER) as the lowest level to go without direct vet supervision.
5. Check the schedule. At a middle rate of 1.5% a week, the dog would weigh about 56.5 lb at week 4, 53.2 lb at week 8 and 50 lb around week 12.

One honest caveat. The same dog’s maintenance needs at 60 lb, as a typical neutered pet, are around 1,170 kcal a day (1.4 × RER), or up to about 1,335 kcal at the top of the AAHA range. Going straight to 727 kcal is a big cut, roughly 40%. The AAHA guidelines describe gentler starting points too, such as feeding 80% of what the dog currently eats, then adjusting. That’s a conversation to have with your vet, who knows your dog’s health and history. Whatever the starting number, the weigh-ins below are what keep the plan on track.

How often should I weigh my dog during weight loss?

Every two weeks is the standard advice. AAHA recommends a recheck every two weeks until you know the plan is working at the right rate, then monthly. Cornell suggests weighing at least every two weeks, and VCA says every other week.

Use the same scale each time, at the same time of day. Write the numbers down.

How do I adjust if my dog is losing too fast or too slow?

The AAHA guidelines use simple 10% steps:

• Losing faster than 2% a week: increase calories by about 10%.
• Losing slower than 1% a week: first check for extra food (treats, chews, scraps, other pets’ bowls, a generous scoop). If intake really is on plan, reduce calories by 10–20%.
• At ideal weight but still losing: increase calories by 10% and keep weighing until the weight holds steady.

If a dog would need fewer than 60% of its RER calories to keep losing, AAHA advises involving a veterinary nutritionist. That’s not a do-it-yourself situation.

What else helps a dog lose weight safely?

Cut the treats, not the fun

Treats should be no more than 10% of daily calories, and that includes chews and the food you use to hide pills. On 727 kcal a day, that’s about 73 kcal of treats. APOP suggests low-calorie swaps such as baby carrots, green beans, cucumber, zucchini, broccoli, celery and asparagus. Our post on how many treats a dog can have a day has calorie counts for common treats.

Measure food properly

A kitchen scale is more accurate than a scoop. Our dog food calculator turns a calorie target into cups or grams for your food, and the guide on how much to feed a dog explains how to read the label.

Build up exercise slowly

AAHA suggests starting with short walks, about 5 minutes three times a day, and working up to 30–45 minutes a day. Heavy dogs can overheat and strain their joints, so build up gradually and keep water handy.

Why does a healthy weight matter so much?

Overweight dogs are the norm, not the exception. APOP’s 2022 survey classed 59% of dogs as overweight or obese. Cornell notes that obesity worsens arthritis, raises the risks of anesthesia and can shorten a dog’s life.

The best-known evidence comes from a lifetime study of 48 Labrador Retrievers published in 2002. Dogs fed 25% less than their paired littermates stayed leaner, lived significantly longer on average, and developed chronic diseases such as osteoarthritis later in life.

Is it different for cats?

Yes, and cats need more care. AAHA’s target for cats is 0.5–2% a week, and a cat that stops eating or loses weight too quickly is at risk of a serious liver condition called hepatic lipidosis. Never put a cat on a crash diet. Our cat calorie calculator and your vet are the place to start, and our post on how many calories a cat needs explains the cat formula.

When to call your vet

• Before you start. Your vet can confirm your dog’s body condition score, set a target weight and check for medical problems that affect weight.
• Your dog is losing more than about 2% of its body weight a week, or is losing weight without trying.
• Weight hasn’t changed after about four weeks on the plan, even though you’re sure about intake.
• Your dog seems lethargic, weak, unusually hungry or thirsty, or is vomiting or has diarrhea.
• Your dog would need very low calories (under about 60% of RER) to keep losing.

Sudden thirst during a diet is worth mentioning too. Our post on how much water a dog should drink explains what counts as too much.