How to Fatten Up A Dog

6 Minute Read
Updated February 10, 2021

7 Tips for How to Fatten Up a Dog

Is my dog too skinny? How do I help my skinny dog gain weight? If you’ve been asking yourself these questions about your pet, you’re in the right place. This guide will teach you everything you need to know about helping your dog safely gain weight.

When you search weight management for dogs, all you get is information about helping your dog lose weight, get in shape, or stay active. But what if that’s not the issue? What if you need to know how to fatten up a dog instead?

If your dog is underweight due to illness, growth, or even poor diet, you’ll need to help her bulk up safely. You could just feed her more, but that doesn’t necessarily translate to a healthier dog.

I know I said fatten up your dog, but our real goal is to build and maintain muscle with a healthy diet and exercise. Appropriate muscle and energy can help improve mobility, joint function, and your dog's overall health, especially as she ages.

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1. Consult with Your Vet

As always, it’s important to talk to your vet about your dog’s weight before you get started on any new diet plan or change in routine. Sudden weight loss or unexplained weight fluctuations could be a symptom of another issue. Make sure your dog is healthy before you try to bulk her back up.

2. Take Baby Steps

There are several ways to help your dog gain weight, but you need to be sure that she isn't putting on the wrong kind of weight or putting on weight too fast. A sudden or drastic weight gain can damage their joints as the pressure of their extra weight increases.

As you begin, make sure you set small goals for your dog. It could be as small as half a pound at a time. Baby steps will allow your pet to gain weight gradually and avoid any subsequent health issues.

3. Know What Changes to Look For

How can you tell if your dog is gaining weight? It’s important to know what to look for as you make changes in their diet and routine. Feel their ribs, hips, and look at them from above and from a profile. Even if their weight hasn't changed much, you can still see progress in their body's definition.

As your pet gains weight and builds muscle, their ribs and hips shouldn't feel as pronounced, and there should be more bulk around the hips, shoulders and chest. This indicates healthy muscle development.

You are also looking at her energy levels. Healthy muscle and the appropriate calories will give your dog consistent energy to participate in her daily routines and activities.

Use this body conditioning score chart to see if your dog is starting to look healthier.


4. Don’t Add Too Much Fat

So what can you give your dog to help him gain weight? The key is to understand what parts of his diet to increase and which parts you should keep the same.

Avoid adding large portions of fat to your pet’s diet. If you are increasing fat and protein, do it in small quantities. Excess fat can add stress to the pancreas and cause digestive issues. Small portions can help them to get used to the increase in both volume and nutrients and prevent unpleasant reactions to the diet changes.

5. Feed High-Quality Calories

To bulk up your dog, of course, you need to increase your dog's calorie intake, but that’s only one side of the coin. As you increase calories, you must ensure that they are calories that she will actually use.

Pumping her full of calories that she isn’t using will lead to weight gain, but not muscle development. Instead, you need to have an appropriate balance of high-quality calories and activity to ensure that her body is using those calories to build muscle and provide energy to her body.

Check out our dog food calculator to help you find the appropriate feeding guidelines to start your dog's weight gain journey. 

Dog Food Calorie Calculator

Food Toppers


Helping your dog bulk up will require calories from high-quality proteins and fats. You don’t necessarily need to change your dog’s whole diet, especially if you are already feeding a meat-rich, premium diet. Instead, you can add to their current diet to help them reach their goal weight.

Here are some tasty toppers that will make your dog’s diet more calorie-dense:

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Human Food


Another way to increase your dog’s calories is to offer them some of your food. I’m sure your dog will jump for joy at that thought. Not all human foods are safe to offer your dog, and not all of them will help you meet your dog’s weight goals.

Here are some of the best human foods to help your dog bulk up:

  • Eggs - Raw, scrambled, over easy. Just make sure they are plain.
  • Cottage Cheese - Full fat.
  • Lean meat - Raw or cooked to match their diet.
  • Quinoa – It provides usable energy and is one of the only carbs that contains a full spectrum of essential amino acids needed for muscle building.

6. Track the Changes

Adding calories to your dog’s diet should be done gradually. You can’t just double her portions and hope for the best. Instead, you need to slowly increase portions over time.

Here’s a basic example of how you can start putting weight on your dog safely.


Tracking changes to your dog's meals and recording weekly weight check-ins can help you to learn what works and what doesn't.

The values in this chart aren’t going to be right for every dog. Smaller dogs will need smaller changes, and a larger dog may be able to handle more drastic increases. Stick to around 10-15% increases at a time.

7. Increase Activity

As you increase calories, you need to increase activity too. An extra 5 minutes on your walk, a few more ball tosses in the backyard, or even some extra mental exercise like puzzles and indoor games can be helpful.

To find out how much exercise your dog needs, check out our Ultimate Guide to Exercising your Dog

Always Play It Safe

Make sure you talk to your vet about your dog’s ideal weight. You want to avoid going over your dog’s target weight and making them chunky. If your dog needs to put on a significant amount of weight, then it’s best to talk to your vet about the safest ways to make more drastic changes to their diet and routine.

Natural Dog Food

Do you have an underweight dog? Let us know how you are helping your dog reach their goal weight. Share your stories, successes, and tips in the comments below!

Written by

Krystn Janisse

Krystn is a passionate pet nutrition enthusiast. She has worked in the pet industry for over a decade and loves to share her passion for animal welfare with others. She loves all animals but is currently channeling some crazy cat lady vibes with her four lovable, but rebellious cats.


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