Is My Dog or Cat Overweight? The 2-Minute Body Check, Calorie Math & a Safe Weight-Loss Plan (2026)

Published October 2026 · ~7 min read

Wednesday, October 14 is National Pet Obesity Awareness Day, and it’s a bigger deal than it sounds. The Canadian Veterinary Medical Association estimates that 50–60% of Canadian pets are overweight or obese, and in a U.S. survey by the Association for Pet Obesity Prevention, nearly a third of owners with overweight pets described them as a normal weight or even thin. Extra weight creeps on slowly, a few treats and a slightly generous scoop at a time, so it’s easy to miss. The good news: it comes off the same way. Here’s how to check, the math that matters, and a plan that works.

How can I tell if my pet is overweight?

Use your hands and eyes, not the scale. Vets use a 9-point body condition score (WSAVA’s chart is the standard), and you can do a quick version at home in two minutes:

• The rib check: run your flat hands along your pet’s sides. You should feel the ribs easily under a thin layer of fat, like the back of your hand. If you have to press to find them, there’s extra padding.
• The waist check: look down from above. A healthy dog or cat has a visible waist behind the ribs, like an hourglass.
• The tuck check: look from the side. The belly should tuck up behind the ribcage rather than hang level or low. (Cats often have a loose flap of skin under the belly, which is normal; a firm, fatty pad is not.)

A useful rule of thumb from the American Animal Hospital Association: each point above 5 is roughly 10% over ideal weight. A dog at 7/9 is carrying about 20% extra.

Why do a few extra pounds matter?

Because they add up to years. In a well-known Purina-funded study of 48 Labrador Retrievers, dogs fed 25% less than their littermates from puppyhood stayed lean, lived a median of 13.0 years versus 11.2, and developed arthritis and other chronic conditions later. It was one breed and a small study, but the direction matches what vets see every day: extra weight is linked to sore joints, reduced stamina and a higher risk of diabetes, especially in cats. A lean pet simply has an easier time being a pet.

How many calories does my pet need?

Start with the formula vets use, then adjust to your pet. Resting energy requirement (RER) is 70 × (body weight in kg)^0.75, and the Merck Veterinary Manual multiplies that by about 1.6 for a typical spayed or neutered adult dog and 1.2 for a spayed or neutered adult cat. Some typical starting points:

These are starting points, not prescriptions. Couch-potato pets and those prone to weight gain need less (Merck suggests multipliers closer to 1.4 for dogs and 1.0 for cats), and the feeding chart on the bag is written for an average, active pet. For weight loss, the AAHA weight management guidelines suggest vets often start around 80% of the RER for your pet’s target weight. For a dog whose ideal weight is 20 kg, that’s roughly 530 calories a day. Your vet can set the right number and check progress.

How fast should my pet lose weight?

Slowly. AAHA recommends about 1–2% of body weight per week for dogs and 0.5–2% for cats. For a 30 kg dog, that’s roughly 0.3–0.6 kg a week. Faster isn’t better: crash diets leave pets hungry and grumpy and tend to bounce back. For cats, it can be dangerous. An overweight cat who goes even a few days without eating is at risk of hepatic lipidosis (fatty liver), a serious condition, so never cut a cat’s food drastically, and call your vet promptly if your cat stops eating. Weigh in every two to four weeks, at the clinic or at home (weigh yourself, then weigh yourself holding your pet).

What are the easiest ways to help my pet lose weight?

1. Measure every meal. A kitchen scale is the single best weight-loss tool, and APOP found only 16% of dog owners and 3% of cat owners weigh their pet’s food. Scoops and eyeballing drift upward over time.
2. Budget the treats. Keep treats and extras under 10% of daily calories. Low-calorie options like Fruitables Skinny Minis (under 4 calories each) or Hill’s Light biscuits help, and so does breaking treats in half, using kibble from the daily ration as rewards, or offering green beans and carrot coins.
3. Make food take longer. A snuffle mat or slow feed bowl turns a 30-second meal into a 10-minute activity, which is more satisfying and burns a little energy. For cats, scatter part of the kibble around the house to hunt.
4. Move a little more. Add 10 minutes to a daily walk and let your dog sniff, or schedule two short wand-toy sessions a day for your cat. Consistency beats intensity.
5. Consider a weight-management food. These recipes are lower in calories and higher in fibre, so your pet gets a satisfying bowl with fewer calories. Portions still matter.

Which weight-management foods does PetMax carry?

Plenty, across budgets and both species. A few our team recommends:

Browse all weight-control dog food and healthy-weight cat food. When you switch, feed by the calorie target rather than the old cup size, and transition over 7–10 days. Pets with a lot to lose may do best on a prescription weight-loss diet from your vet.

When should I talk to my vet?

Before starting a plan if your pet scores 7 or higher, and any time weight changes without an obvious reason. Sudden weight gain can point to conditions like hypothyroidism in dogs, and unexplained weight loss (especially in older cats) is always worth a checkup. Your vet can confirm the target weight, rule out medical causes, and set a calorie number you can trust.

The bottom line

Check the ribs, the waist and the tuck. If your pet is carrying extra, measure meals, trim treats to 10%, make food work a little harder, and let the weight come off slowly. It’s one of the kindest things you can do for your pet’s joints and lifespan, and our team is always happy to help you find a food and treat plan that fits.

PetMax.ca is a family-owned, Canadian pet supply retailer based in Hamilton, Ontario. We’ve been helping pet owners since 1993, ship across Canada with free shipping on orders over $89*, and offer free local delivery in Hamilton and Burlington on orders over $30*. This article is general information, not veterinary advice. When in doubt about your pet’s health, contact your veterinarian.
*conditions apply