How to Fatten Up a Dog: Considerations and Tips

Filed in Dog Health by on July 10, 2021

how to fatten up a dog

Is your dog looking a little skinny? Keeping proper weight on your dog is critical in making sure they live a long and healthy life.

There are some easy steps to help you determine if your dog is too skinny and steps you can take to get them back to a proper weight.

In this vet-reviewed and approved blog post by a licensed DVM, I discuss what to consider and how to fatten up a dog to bring their weight back to normal.

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How to Tell If Your Dog Is Too Skinny

Before you start trying to put weight on your dog you should thoroughly evaluate your pet’s overall body condition. Veterinarians and pet nutritionists assess a dog’s weight by giving them a body condition score.

This score is a number between 1 and 9 where a dog with a body condition of 1 is considered severely underweight while a dog with a body condition score of 9 would be considered severely obese.

The American Animal Hospital Association has a detailed chart showing what you should be able to see and feel for a dog at each of the different body conditions scores.

This can be a great tool to help you determine where your dog falls on the scale. Regular assessments can also help you monitor any changes or progress.

Some things to look for if you’re concerned your dog falls on the lower end of the scale include:

  • Clearly visible ribs, hip bones, and/or spine
  • A pronounced waist that tucks up drastically behind the rib cage
  • Little or no visible muscle mass or body fat

Underlying Health Conditions

Veterinarian examining beagle

If you’re worried about your dog’s weight, the most important thing is to get your dog examined by your veterinarian. Many medical conditions can cause weight loss and it’s important to make sure your dog has a clean bill of health.

Oftentimes, weight loss brought on by health conditions may come on suddenly. Consistently tracking your dog’s weight and body condition can be very helpful when discussing your concerns with your veterinarian.

Make Sure Your Dog Is Eating Enough

Once your dog has a clean bill of health, the first thing to determine is if your dog is eating enough. Try keeping a log of how much you are feeding your dog, how often you are feeding them, and how much of the food you give them do they actually eat.

It’s important to stay consistent with your measurements. One easy way to do this is to have a designated set of measuring cups that you use to measure out your dog’s food for every meal.

Now that you know how much your dog is eating, you can determine if what you are feeding them is appropriate. Most dog food brands contain a chart on the packaging that provides nutritional information and feeding recommendations.

Veterinary nutritionists have many complex calculations for determining your pet’s calorie and nutrient needs. However, a good place to start is to look at the feeding recommendation chart on the dog food packaging.

Remember that if you want your dog to gain weight you should be looking at the feeding recommendation for your dog’s ideal weight, not their current weight.

If you are unsure what your dog’s ideal weight should be, try researching the breed or talking to your veterinarian.

Compare the amount of food recommended for your dog’s ideal weight to the amount of food your dog is currently eating. Slowly increase your dog’s food and continue to monitor their weight.

Pick the Right Diet for Your Dog

If simply increasing the amount of food your dog is consuming isn’t working, you may consider changing the food formulation.

The two most important nutritional factors when trying to fatten up your dog are protein and fat. Many dog food companies market special formulations for performance dogs that are higher in fat and protein.

An additional advantage of these performance formulas is that they are more calorically dense.

For dogs struggling to eat the larger amounts of food needed to get in more calories, a performance formula can help them get those calories in a smaller quantity of food.

Another important consideration in picking the right diet for weight gain is how appetizing the diet is to them.

While performance diets come in a variety of flavors, some dogs prefer canned wet food over dry dog food. As a general rule, dry food tends to be more calorie-dense than wet food.

But no matter how calorie-dense a food may be, if your dog doesn’t like the food, they won’t consume enough calories. Topping or mixing a small amount of wet food with your dog’s dry food is a good trick to make the dry food more appetizing.

Product Recommendations on How to Fatten Up a Dog

Eukanuba Premium Performance 30/20 Sport Dry Dog Food:

Eukanuba’s Premium Performance line focuses on high protein and high-fat diets to fuel dogs with increased nutritional needs. The Eukanuba Premium Performance 30/20 Sport Dry Dog Food contains 30% protein and 20% fat, a significant increase from most of their standard adult formulas.

Purina Pro Plan All Stages Sport Performance 30/20 Chicken and Rice Dry Dog Food Formula:

Similar to Eukanuba’s Premium Performance line, Purina offers a Sport Performance line that focuses on high protein, high fat, calorie-dense diets.

For example, Purina Pro Plan All Stages Performance 30/20 Chicken and Rice Dry Dog Food Formula offers about 100 calories more per cup than their Adult Large Breed Chicken and Rice Dry Dog Food Formula.

One advantage of the Purina line is that they offer a wide variety of flavors, which is great for picky dogs.

Purina Pro Plan Sport High Protein Chicken and Rice Wet Dog Food:

Although part of the Purina Pro Plan Sport line it’s important to note that although this product is listed as a high protein wet food, the product contains only 10% protein.

The advantage of this product is that the label gives clear instructions on how to combine the product with Purina’s Pro Plan dry food to meet your dog’s nutritional needs.

Make Food Transitions Slowly

Man feeding his beagle dog

Now that you’ve learned of some products and tips on how to fatten up a dog, you may need to transition to a different type of food. However, it’s important to do it gradually. Changing your dog’s diet too quickly can cause gastrointestinal issues including vomiting and diarrhea.

Transitioning your dog over a 1-2 week period can reduce the risk of stomach upset. Below is an example of how to gradually make this transition over two weeks.

  • Day 1: 75% original diet and 25% new diet
  • Day 5: 50% original diet and 50% new diet
  • Day 10: 25% original diet and 75% new diet
  • Day 14: 100% new diet

Avoid Table Scraps

Although it can be tempting to feed your dog your extra leftovers when you feel like they’re looking a little thin, this may be causing more harm than good.

Table scraps can contain ingredients that are detrimental to the health of your pet. In some cases, feeding table scraps can cause nutritional imbalances that can negatively affect your dog’s health and weight goals.

No matter how tempting it may be, avoid sharing those last bites with your furry friend at the end of your meal.


Once your dog’s dietary needs are addressed, increasing their physical activity can help improve muscle mass. Without proper nutrition, too much exercise can cause a calorie deficit and weight loss.

Finding a healthy balance is key. Maintaining your dog’s physical fitness can help maintain a healthy weight, a vital part of their overall health.

I even wrote an article on toys for bored dogs to keep your dog entertained and moving.


At the end of the day, we all just want our dogs to be healthy and happy. If you have concerns about your dog’s weight, it’s important to talk to your veterinarian first.

Your veterinarian can help you determine if there is a medical reason your dog is underweight and how to treat any underlying illness.

Every dog’s weight journey is different, but hopefully, these tips can help you formulate a plan to get your dog back on track.

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