Are you tired, run-down, listless? Do you poop out at parties? Are you unpopular? The answer to all your problems lies in this simple test.

At least, that's how the commercial would sound, encouraging your dog or cat to see if it's the extra baggage around their ribs (and neck and chest and hips...) holding them back from romping at the dog park with their buddies, keeping them from clearing that once-easy-to-leap fence, and bringing down their overall health.

fat cat on fence

Photo: /Shutterstock

There's a rising problem of obesity among pets. According to a study by Zoetis, "veterinarians consider 47 percent of their patients overweight or obese but only 17 percent of dog owners think the same. Why the difference? It could be denial or the difficulty owners have in recognizing when their dogs are overweight."

It is understandable. Not only can it be hard to know if your pet is on the pudgy size if you aren't trained in animal health, but pet owners love their pets, and often show love by offering treat (after treat after treat) and letting them catch scraps from the table, on top of the already hefty portions in their food dishes at meal times. Or worse, pets are allowed to "free feed" with food being left out constantly so they can snack whenever they feel like it.

Ultimately, we aren't doing our pets any favors by being lenient with the food. Extra pounds on a cat or dog means higher odds of having arthritis, heart and respiratory conditions, heat stroke, skin conditions and a whole range of other related health problems. And it just looks so uncomfortable:

fat labrador dog

Photo: /Shutterstock

No one wishes any of those health problems on their furry family members. So how can you determine if your pet needs to get more exercise and go on a diet? It's as easy as holding up your hand. Literally.

The Knuckle Test

In general, feeling your pet's ribs is a great way to tell if they are over (or under) weight. How much meat they have on their bones will tell you, and you can use the bones of your hand as comparison. There are two versions of this test. Both are equally helpful in helping you gauge your pet's weight.

The first version is to make a loose fist with your hand. Run your fingers over the back of your hand, then over your knuckles, then over the back of your fingers near the knuckles. If your dog or cat's ribs feel like the bones in the back of your hand (as in, you can't feel them very well) then they're probably overweight. If their ribs feel like your knuckles, then they're probably underweight. And if your pet's ribs feel like the backs of your fingers — meaning you can feel each rib but there's some padding around them — then your pet is probably at just the right weight.

The second version of this test is similar. Make a tight fist and run your fingers over your knuckles. Each bone is prominent. If your pet's rib cage feels like this, they're underweight. Then hold your hand flat and run your fingers over your knuckles. You can feel each knuckle but not quite as easily. There's a little padding there. If your pet's ribs feel like this, they're probably at the ideal weight. And finally, flex your hand tight, stretching your fingers as far back as they'll go, and you guessed it, run your fingers over your knuckles. It's not nearly so easy to feel your knuckles. If your pet's ribs feel like this, it's time to cut back on the treats and bump up the exercise.

Even with this test, sometimes it can be hard to tell if our dog or cat is overweight if they have a particularly fluffy coat (we're looking at you, Samoyeds), or has a stocky build (hello, English bulldogs). If you still aren't sure if your cat or dog is on the heavy side, it is worth a trip to the veterinarian to get professional input. The one visit to determine your pet's ideal weight could save you many more visits in the future.

dog eating food

Photo: /Shutterstock

4 easy ways to slim down your pet

1. Stop free-feeding: If you leave a bowl of food out all day for your pet, it's time to put the bowl away and set up a feeding schedule. A little something for breakfast and a little something for dinner is all an adult cat or dog really needs. Even if your pet doesn't polish off the whole bowl at once, it doesn't mean that they're eating only what they need. It's clear by your pet's weight that they're probably eating a little more than they need every time they visit their dish. To help them shave pounds, put away your pet's food.

2. Save treats for special occasions or training: Dishing out treats nonstop is an easy way for your pet to pile on the extra calories. Make treats a super special thing, something they either get rarely or something they earn through exercise or training.

3. No more table scraps: Feeding pets from the dinner table is a big no-no for many reasons, including weight gain. Table scraps are loaded with extra calories (and additives, preservatives, sugar, and other things) that your pet doesn't need. Select a high-quality food for your pet and stick with that. They may look super cute when they ask for a little nibble from your dinner plate, but saying "no" to the begging is the real way to show them you care.

4. Ramp up the exercise (slowly!): Add in more time every day for exercise. But, just like an out-of-shape human should avoid going overboard on the exercise when beginning a new training routine, cats and dogs need to slowly add a little more exercise a day while they build up their muscles and lose the extra weight. Too much too soon can lead to heat stroke, muscle tears or joint problems. So add just a few extra minutes of walking or playing each day so your pet can get their figure back while avoiding injuries.

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Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.