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Weight management 101: Your guide to feeding an underweight or overweight dog

April 18, 2023

Weight management is an important consideration at all stages of your dog’s life. While more than half of our canine companions in the U.S. have obesity, it’s also important to be vigilant to unintended weight loss so pets can be evaluated and treated for underlying medical issues.

Why is dog obesity a problem? As a pet parent, you might think a little pudge on your pup is a cute look, but it can harm their health in the long run.

  • Carrying extra weight make their favorite activities like walks and playtime less enjoyable because it amplifies the pain of joint and bone diseases such as arthritis and hip dysplasia, while pressure on the lungs makes them more easily winded.
  • Obesity in dogs is linked to higher risk of secondary conditions, including hypertension, heart disease, diabetes and cancer.
  • Dogs with obesity have shorter lifespans by up to 2.5 years, compared to those of dogs with a healthy body weight.

Unfortunately, pet parents have a blind spot to the extra pounds their pet carries. Only 39% of dog owners consider their pet overweight or as having obesity, according to Pet Obesity Prevention.

To help you keep your pet at a healthy weight, use this guide to feeding your dog to find the right balance.

Is my dog overweight? How to calculate your dog’s BMI

To determine if your dog is at a healthy weight, you may be wondering how to calculate your dog’s BMI. After all, humans use the BMI (Body Mass Index) to determine if they’re in a healthy weight range. Does this apply to dogs?

Short answer: Yes, a dog’s BMI can show you whether your dog has excess fat and by how much by crunching a formula that calculates their weight-to-height ratio. You can easily find dog BMI calculator online that’s calibrated for your dog’s breed. But there are some caveats you’ll want to consider.

Accurate dog BMI data is breed specific: A dog BMI calculator is only useful if it factors in the breed. There’s no single BMI formula that works for all dogs because bone size and bone structure vary so widely between dogs. This creates a wide range of healthy weight targets.

Size matters for dog BMI: To illustrate, let’s compare a male Afghan Hound to a male Alaskan Malamute. Both stand at an average 27” in height from shoulder to floor. But the gap between their weight targets is a whopping 27 pounds.

  • Afghan target weight: 58 pounds
  • Malamute target weight: 85 pounds

The Afghan is long and slender while the Malamute has a stocky build for those demanding northern winters. A BMI of 56 indicates a healthy weight for the Afghan, but dangerously underweight for the Malamute.

Is dog BMI worth calculating? Bottom line, a breed-specific dog BMI calculator is one way to benchmark your dog’s level of body fat and monitor their progress on a weight loss plan. But it can be just as easy to learn your dog’s healthy weight range through your vet or the AKC (which has already taken the time to compile accurate weight targets for dog breeds based on their physical characteristics). Calculating dog BMI is an extra step that won’t reveal any astonishing insights.

Body Condition Score: The vet-backed alternative to dog BMI

The good news is, there is a vet-backed alternative to dog BMI and that is the Body Condition Score (BCS). Vets recommend that pet parents use this visual guide to help their pets catch changes in their pet’s size so they can help them get back on track to a healthy weight.

How does the Body Condition Score work?

The Body Condition Score lets you do a quick and simple assessment at home, where you examine the shape of your dog’s body, checking for excess fat.

Once you check your dog, and find a match for their condition, you receive their BCS on a scale of 1-9, with your dog falling within one of three segments:

  • 1-3 is thin to very thin
  • 4-6 is just right
  • 7-9 is overweight to obese

How to tell if your dog is overweight

How can you tell if your dog is overweight or has obesity? According to the BCS, these are the tell-tale signs:

  • Thicker layer of fat around the ribs, spine and pelvis
  • No tapering of the waistline
  • Little or no tucking in the abdomen
  • Abdomen rectangular or oval shaped

Once you have your dog’s Body Condition Score, share your findings and concerns with your vet. If your dog needs to lose a few pounds, they can help set the healthy targets.

How to manage your dog’s weight

If your pup is overweight or has obesity, it may be time for a reset on how much you feed your dog. If your dog is overweight and always hungry, here are some guidelines to help them get their weight back into balance.

Right-size the portion

How much do you feed your dog and how many calories do they need? Fortunately, there’s an easy way to find their daily allotment and stick to it. With the help of your vet, start with the target healthy weight for your dog. Use that to find the right daily serving of dog food on the kibble bag’s feeding chart.

Fortify with fiber

Adding fiber to your dog’s diet is a proven weight-loss method for dogs (as well as humans). Adding cooked frozen or canned veggies to your dog’s bowl (such as carrots or green beans) will add low-calorie volume to your dog’s stomach which helps them reach the satiation point more quickly.

Try a healthy weight diet

Using a weight management diet as an aid to help your dog reach their goal is another healthy option. A weight management diet has fewer calories, less fat, higher protein and more fiber than a regular adult diet.

Mind the treats

The world’s easiest trap to fall into is doling out shares of your meal or snacks in response to the pleading eyes of a desperate dog. Rather than going cold turkey on the handouts, try keep healthy but low-calorie alternatives on hand, such as crunchy carrot sticks, apple slices or air popped popcorn.

What if my dog is underweight?  

Dogs that fall under their ideal weight can also be a cause for concern. If you’re wondering if your dog is underweight, a quick at-home assessment using the Body Condition Score is a great starting point.

Signs that your dog is underweight

If you want to know how to tell if your dog is underweight, these are some of the surefire physical signs, according to the BCS:

  • The bones of the ribs, spine and pelvis are visible and prominent. (If your dog has a long coat, feel along the surface of the skin — bones should not be sticking out.)
  • An absence of fat along the ribs, spine and hip bones, coupled with signs of muscle loss
  • An exaggerated waistline and abdomen tuck

Rule out medical issues

Dogs can lose weight for medical as well as lifestyle reasons. Some dogs are highly active and burn a lot of fuel! A vet visit can identify or rule out underlying medical issues, including dental disease, an overactive thyroid or cancer.

Proper portioning is key

Once you’ve ruled out medical issues, a high-calorie dog food might be the answer for underweight dogs. One way to go about this is increasing the portion size to the high end of the kibble’s feeding range for your dog’s size listed on the chart. Another route is switching to an active dog diet with the macros and nutrients — more fat, calories and protein — to fuel their busy days.

Factors of dog weight management  

The guidance is simple for maintaining healthy weight — proper portioning and making sure your dog is getting plenty of activity. However, there are several factors in play for your dog, including age, breed, size and activity level.  

Weight management for small vs. large dogs  

Size can definitely throw in some challenges when you’re managing your dog’s weight. The smaller the dog, the greater the impact of one pound of weight lost or gained.

Weight changes have higher impact: A 1-pound weight gain on a 10-pound dog is a 10% weight increase. But on a 100-pound dog, it’s a much less noticeable 1% increase. By the same token, a 1- or 2-pound weight loss on that small dog is not inconsequential.

Monitor the treats: To keep that smaller dog from runaway weight gain, keep close tabs on the number of treats and handouts. Because their bodies need fewer calories, it only takes a few before these small dogs are overextended.

Young and old: Weight management for dogs of all ages

Weight management practices will also shift depending on your dog’s age.

When your dog was younger, they may have been bottomless pits of fuel for their long days of exploration and play. Once a dog reaches middle age, they often reach a turning point in their energy levels.

Do dogs eat less as they age? It depends on the dog! Your middle-aged dog may have the same appetite level as his younger self. But if he’s less active, he’ll be sure to put on some excess pounds.

As dogs age, it’s important to adjust their diet to their evolving energy needs. In fact, obesity is one of the core issues pet parents face as their dogs grow older. But with awareness and strategy, you can help your senior dog maintain a healthy weight.

Beyond BMI: Focus on optimized nutrition

Being proactive about helping your dog maintain a healthy weight is critical. But don’t lose sight of the fact that your best friend needs the full range of nutrients only a high-quality food system can offer.

For instance, did know each protein source has a unique amino acid profile? Each plays a role in building healthy cells and keeping the body’s systems running at optimal levels. To help your dog achieve optimal health at any age, practice Full Circle Feeding, by rotating the different protein sources in your dog’s diet.

Intrigued? Get started by checking out our Ultimate Guide to Full Circle Feeding.

Keep your dollars local and buy NutriSource products from one of the independently owned and operated pet suppliers in your community.

Section 4: FAQs about dog weight management

Still have questions? Here are some answers to the most frequently asked questions about weight management for your dog. 

Q. Should I buy dry or canned dog food for weight management?  

A. Canned food can help your dog reach their target weight, whether you serve it on its own or mix it with kibble. The additional water content and higher protein count in wet food can make your dog feel more satiated after the meal. But for an underweight dog that needs a little persuasion at the bowl, the enticing aroma of canned food can tempt their appetite.

Q. What is the best dog food for weight loss?

A. The best weight management diets are lower in calories with lower fat content compared to regular maintenance diets. Look for the inclusion of l-carnitine, an amino acid that helps fatty acids burn energy.

Q. How many calories should my dog eat?

A. The number of calories your dog should eat depends on their target weight, age and activity level. Puppies, for example, should eat three daily servings of a high-calorie puppy diet, while an older dog can get their needs met through a senior diet that has less fat, fewer calories and higher fiber. The feeding chart on your bag of kibble is calibrated for ideal daily calorie range for your dog’s age, weight and activity level, so that’s the best starting point.

Q. Why is my dog overweight but doesn’t eat much?

A. If your dog isn’t overeating  — or even eating less than they should — but still carries extra pounds, that can be a sign of an underlying medical condition that needs diagnosis and treatment from a vet. For example, an underactive thyroid is a common culprit for this scenario, because this small organ is the control center of your dog’s metabolism. Get the vet visit scheduled, and take detailed notes of what your pet is eating and how much before the visit to help find the root cause of your pet’s issue.