Overweight and Obese Dogs: Everything You Need to Know | KetoNatural Pet Foods

Overweight and Obese Dogs: Everything You Need to Know


America’s more than 100,000 veterinarians are in near-unanimous agreement:

Obesity is the single biggest health problem facing dogs in the United States today.

That’s a big claim, but it’s not wrong. 

Studies show that being moderately overweight is worse for a dog than a lifetime of smoking is for a human being. On average, the fatter the dog the shorter its expected lifespan. If your dog is clinically obese, it is likely, on average, to cross the rainbow bridge some 30% earlier than if it was a healthy, normal-weight dog. That translates into dying anywhere from 2 to 5 years too early.

With such disastrous health consequences, you’d think that canine obesity in dogs would be rare. But you’d be wrong. In fact, the majority of dogs in America today are overweight or obese. There are literally more fat dogs than fit ones in our country.

And what do you get when more than half the dogs in the country are suffering from a disease that is deadlier than a lifetime of smoking? You get what is undeniably the single biggest health problem facing dogs in America today.

Thankfully, unlike many diseases (such as most cancers), canine obesity is almost always incredibly easy to treat. In the vast majority of cases, helping your dog lose weight is inexpensive, simple, and low-stress for everyone involved. If you don’t want to, you don’t even have to pay for a vet visit. 

All you have to do is read this article, spend another five minutes or so doing some diagnostic work and making some decisions about what you feed your dog, and the rest will take care of itself over the coming weeks and months. 

Your expected return on those ten minutes of time investment? A dog that lives, on average, two to five years longer. Not bad, right?

How Do You Know If Your Dog is Overweight or Obese? Use A Body Condition Scoring Chart

Simply weighing your dog won’t necessarily tell you whether or not the animal is overweight. Because to a much more significant degree than most species, equally healthy dogs can differ hugely in size. (My Saint Bernards, for instance, weigh more than ten times as much as plenty of toy breeds. Let me know if you’ve ever come across another human being that weighs ten times as much as you do.) 

Breed standards (even “official” ones blessed by the AKC) don’t really help. Some don’t even include recommended body weights. And those that do aren’t based on any kind of scientific evidence and usually recommend ranges that are too big to be helpful anyways. I recommend that you just ignore them.

Moreover, body weight and body fatness aren’t the same things. In fact, muscle tissue is more dense than fat tissue. Being heavy doesn’t necessarily mean you’re fat. Plenty of relatively heavy dogs are actually supremely lean. 

So how do you tell if your dog is too fat? Do what vets do: use a body condition scoring (BCS) chart. These ingenious little tools use images and text to describe a variety of different canine body shapes (from “too lean” to “too fat”). And all you have to do is pick the ones that best match your dog's body.

Here’s the most popular BCS Chart:


And here’s another:

And here’s one that I actually created myself, once upon a time:

It doesn’t really matter which one you use. They’re all quick and easy, and they don’t require a medical degree. They’re all reasonably accurate (and you won’t need pinpoint precision to understand whether you’ve got a problem on your hands anyway). So just pick your favorite and have at it!

What To Do If You Have an Overweight Dog?

Okay, so you’ve downloaded a BCS chart and used it to diagnose your dog’s body condition. And it looks like your dog would be healthier and live longer if it lost a few pounds of fat. What next?

First, don’t spend even one second feeling guilty. It isn’t your fault and you have absolutely nothing to feel bad about. We all love our dogs and we’re all trying our best. 

Problems like canine obesity (that are both deadly and incredibly easy to fix/prevent) don’t become epidemics by mere ignorance or laziness. There’s usually something more to it. And, indeed, in this case there is. It’s the pet food industry. 

It’s beyond the scope of this article, but if you want to understand the many ways that the pet food industry has conspired to create a nation of overweight dogs, I humbly suggest you check out my book (you can download a free e-version here). Or you can just trust me when I tell you that it’s not your fault, I promise.

Instead of feeling ashamed, just pick one (or more) of the three strategies below and start making changes today. They’re all legitimately easy – two of them don’t even require you to leave the house – and they can be combined (or not) depending on your personal circumstances and preferences.

The three different general strategies that have been shown to reduce body fat in dogs are as follows: (1) reduce digestible carbohydrate intake; (2) reduce total energy intake; or (3) increase energy output through exercise.

The Best Way To Help Your Dog Lose Weight: Reduce Carbohydrate Intake

Peer-reviewed experiments have shown time and again that reducing carbohydrate intake tends to reduce body fat in dogs, even without reducing total caloric intake. Said another way, carbs make dogs fat and the best way to eliminate some fat from their bodies is by eliminating some carbs from their diets.

Why is this the “best” of the three fundamental canine weight-loss strategies? For several reasons.

First, it has other positive health ramifications. This is because dietary carbohydrates alter canine metabolism. All digestible carbs get converted into pure sugar during digestion, causing violent blood sugar spikes after every carbohydrate-rich meal. These spikes cause dogs to burn more carbohydrate-derived glucose for energy and less of their own stored body fat. And (over the long run) this change has other significant health consequences that go well beyond body composition, such as insulin resistance.

Second, it’s easy. Exercise is great, but only if it fits your lifestyle. Dietary changes, on the other hand, just require a little bit of forethought and decision-making (and maybe some extra spending, depending on what you’re currently feeding). That’s it.

Third, dietary changes are more potent than most forms of exercise. A helpful way of thinking about body fat is that each pound of the stuff contains about 3500 calories worth of energy. And a 50-pound dog burns fewer than 100 calories with every mile of walking. So, all else being equal, taking your 50-pound dog for a one-mile walk every day will reduce its body fat by only a single pound every 6-8 weeks. Dietary changes can reduce body fat much more quickly and efficiently.

Fourth, protein and fat are essential nutrients that your dog needs for optimal health. Reducing total caloric intake (by choosing a “weight loss” pet food or simply feeding smaller daily portions) will necessarily reduce the amount of these vital nutrients that your dog ingests. But simply reducing carbohydrate intake won’t. In fact, most low-carbohydrate dog foods contain much more protein than high-carbohydrate ones.


If these points make sense to you then all you have to do is swap out your existing brand of dog food for one of three primary low-carb options:

  • Ketona. This is the low-carb, high-protein kibble that my company makes. It contains less than 5% digestible carbohydrate, which is about as little as you can find in a commercially available pet food. It also contains about 50% protein, which is about as much as you’ll find anywhere.
  • The low-carb kibble sold by Visionary Pet Foods. The primary quality that distinguishes Visionary from Ketona is the protein content. Both products contain only miniscule amounts of digestible carbohydrate, but Ketona contains much more protein whereas Visionary contains much more fat.
  • A low-carb raw product like the ones sold by Primal Pet Foods. These are great options if you don’t mind the added sanitation and preparation work involved in feeding a raw diet and if you have a very small dog (or a very large pet food budget), as they cost 2-3 times as much as the low-carb kibbles do.

Reduce Energy Intake With Portion Control And/Or A “Weight Loss” Dog Food

The second strategy that has been shown to reduce body fat in dogs is outright caloric restriction. This can be done in two different ways: by feeding smaller daily portions or by feeding less energy-dense foods. Both are incredibly simple.

If you’d rather not switch brands, portion control is the option for you. The primary challenge with this strategy is determining how small to make the new meals. Simply reducing the size of each portion won’t necessarily produce weight loss, you’ll need to reduce the portions by enough that the net result is an energy deficit.

Alas, this means math. But don’t worry, it’s not too difficult.

A commonly-used rule of thumb is to target weight loss at a rate of about one percent per week. So start with your dog’s current body weight and figure out what one percent of that is. That’s your target weekly weight loss.

As mentioned above, it’s accurate enough to think of each pound of weight loss as requiring about 3500 calories worth of deficit. So convert your weekly weight loss target into a calorie deficit target by multiplying it by 3500.

Last but not least, convert that number into a daily caloric deficit target by dividing it by seven. Assuming that your pre-existing portions are holding your dog’s weight steady +(as opposed to actively putting weight onto the animal), you’ll want to reduce your daily portions by your daily deficit target.


An example may help. 

If your dog weighs 50 pounds, you should be aiming for weight loss of about 0.5 pounds per week (one percent of 50). Multiply 0.5 by 3500 and you get 1750 calories of energy deficit every week. Divide that number by 7 and you get a daily caloric deficit of 250 calories. 

From there just read the label to figure out how many cups/scoops of food corresponds with your target caloric deficit and off you go. (And remember that a “cup” is a specific unit of measurement, not some huge styrofoam cup from a convenience store!)

The idea with “diet” dog foods is essentially the same thing, except you don’t have to do any calculations—the manufacturer just removes the calories for you. 

Pet foods contain six constituent parts: digestible carbohydrates, protein, fat, indigestible fiber, moisture, and ash. But only three of these items (carbs, protein, and fat) actually contain calories. Fundamentally, all “weight loss” and “diet” dog foods contain somewhat less of the calorie-containing nutrients and somewhat more of the calorie-free stuff, which lowers the overall calorie content.

With these products, you don’t have to do any math to determine how much to feed your dog. Just follow the feeding recommendations on the label.

Increase Energy Output With Exercise

Beyond mere weight loss, there are several benefits to incorporating exercise into your dog’s weight-loss plan, whether it is used as the only strategy or in conjunction with dietary changes.

First, if “fat is poison” then “muscle is medicine.” Having a significant amount of skeletal muscle mass is undoubtedly a healthy, positive thing for a dog. And you can’t build muscle without exercise.

Second, it’s fun. Obviously most dogs love going for walks, playing fetch or tug games, and wrestling with other dogs at the dog park. Doing something your dog enjoys while also improving the animal’s health is a double bonus. A win-win.

So it won’t surprise you to know that I’m a huge proponent of exercise, both for dogs and for people. My dogs always get at least one daily exercise session, whether that’s a jog, a trip to the dog park, or something else.


That said, it also has its limitations.

Not everyone has the time, patience, and physical ability to exercise alongside their dog. (Or the financial wherewithal to pay someone else to do so.) And, as I mentioned above, exercise also isn’t as efficient a fat-loss strategy as diet. It takes a lot of exercise if you want to move the needle.

If you want to estimate the amount of exercise your dog needs in order to achieve your weight-loss goals, here’s a little equation that will help:

One calorie/pound of body weight/mile

So if your dog weighs 50 pounds, it will burn roughly 50 calories per mile. (Note that this is just an easy-to-remember estimate, it actually undershoots the real total by a little, but not much.)

In order for this equation to be helpful you’ll obviously have to estimate the distance the animal is going to cover during each exercise session. That’s easy for walks and jogs but a bit more challenging when it comes to fetch games and dog park visits. Just do your best – it’s only an estimate.

Once you have a rough sense of how many calories your dog will burn during its exercise sessions, you can combine that information with whichever dietary strategies you’ve adopted in order to get a good sense of how long it will take your dog to lose each pound of body fat. Then all you have to do is use your BCS chart to identify your dog’s target body condition and stay the course until you reach it. 

And that’s it. Simple and easy, right? And with benefits as huge as two to five extra years of lifespan, there’s really no excuse not to get started today. Good luck!


Dr. Bruce D. Armstrong, DVM

Dr. Armstrong is a veterinarian with decades of experience in private practice, primarily focused on treating companion animals.

He reviews all articles to ensure that discussions of scientific topics are fair, balanced and accurately reflect the state of the peer-reviewed evidentiary record.

Learn more about Dr. Armstrong