How to Fatten Up a Dog: 8 Ways for Weight Gain

Image showing little puppy laying down and looking at the camera
Wyatt Robinson
Written by Wyatt Robinson

Many dogs suffer from obesity, however, there are some cases where your dog may be experiencing the opposite. Helping your dog gain weight may seem as simple as feeding them a couple cheeseburgers and not letting them go for a walk for a couple weeks, but if you use such methods, your dog’s weight gain won’t be healthy. So that your dog can reach the desired weight with a proper balance of muscle to fat ratio, you need to know the proper answer to the question how to fatten up a dog.

Fattening up a dog is not as difficult as it may seem if you know the right way to do it. Perish all thoughts of giving your dog oily and fatty food. The methods in this article are designed to give your dog the right balance between muscle and fat by feeding them wholesome food and allowing them to have proper exercise while reducing their stress levels. You’ll see a difference as quickly as after a few weeks or months of application, depending on the dog’s own propensity.

Image showing a skinny ogar


In this article, we will first try to help you determine the cause behind the dog’s lack of proper body mass. Afterwards, we will let you in on a surefire way to help them gain weight quickly and healthily. With the proper knowledge and tools, you’ll be able to help get your dog to their ideal weight.

Why is it Bad for Your Dog to be Underweight?

It’s normal for dogs to be underweight, specifically if the dog’s been under a lot of stress or has been ill. Though as humans, we tend not to see being thin as a problem, with dogs, it can dramatically affect their long-term health. Being underweight can have a drastic effect on the entire body of your dog. It may cause:

  • Hair loss
  • Muscle loss
  • Internal organs such as kidneys, liver, and the heart may work less effectively
  • If female, the dog may have issues with fertility.

Is Your Dog Underweight or Overweight?

Before you do anything, you need to determine whether your dog is under or overweight, as the solution for either is dramatically different. If your dog is overweight, well, feeding it more food won’t solve the problem.

Ideally, the best way to determine whether your dog is over or underweight is to consult your vet. Your vet is trained with the knowledge of various breeds, so they’ll be able to calculate the weight in relation to the breed of your dog. However, you can also figure it out without a vet. The best way to determine whether your dog is over or underweight is by looking at the rib cage.

Image showing a fat dog laying down

If your dog is healthy, you’ll be able to feel the ribs just under the skin when you put your palms on his sides. However, if you’re able to see the ribs, it shows that the dog is underweight. If this is the case, you’ll also see a curve from the waist to the rib cage.

Now that you know what an underweight dog looks like, you may be wondering what causes this situation.

Why Your Dog May Be Underweight

Here are some of the reasons why your dog may be struggling with gaining weight or suffer from a loss of appetite.

The dog is stressed

Just like humans, when dogs are upset or stressed they may not want to eat. If your dog’s environment isn’t clean and spacious, then it may be a cause as to why your dog may not be eating properly.

Image showing a stressed dog

If they’re having issues with other dogs or people in your family via intimidation, physical scolding or constant obedience, this is another cause for your dog to experience stress.


If a dog is experiencing stomach problems or another health issue, they may choose to eat less. You’ll have to keep your eye on your dog for a couple of days. It could be a momentary illness or stomach issue, or it could be more severe. If you don’t notice their appetite changing after a couple of days, then you should consult a vet.

They are Picky Eaters

Who would have thought that dogs would be picky eaters? Well, it’s true (in some dogs)! They’re not into the conventional dog food anymore, so you may want to switch to gourmet meals.

Winnie loves Humankind food for dogs

You can add treats to their meal for extra calories, however, they still need to eat their dog food as it’s fully packed with nutrients. Food such as cooked chicken, beef, yogurt, lamb, and fish are all appropriate treats to incorporate with your dog’s dry food.

Parasites are involved

When your dog has parasites, it can severely interfere with his/her appetite. Hookworms, whipworms, and giardia can all negatively interact with your dog’s digestive system because they absorb the nutrients that your dog should be absorbing.

Image showing a dog not feeling good

These parasites can be spread through contaminated water, fecal matter, etc. You’ll be able to see if your dog has parasites by looking at a combination of factors. If your dog is coughing, experiencing diarrhea, hair and weight loss, or reduce appetite, then there’s a high chance they have parasites.

Over-the-counter parasite medications for dogs are available, but if your dog is rather old or not perfectly healthy, make sure to consult a vet before you medicate them so there wouldn’t be any unexpected side effects.

Low-Quality Food

The dog food you choose to feed your dog is extremely important for your dog’s health and vitality. Feeding your dog low-quality dog food is equivalent to feeding your child McDonald’s for every meal and we all know how that negatively affects humans, so this is no different.

Dog not eating his food

If your dog’s food is of low-quality, it will not provide them with the proper nutrients and fats needed. So, make sure to invest in high-quality food if you want to have a healthy dog. Low-quality dog food also contributes to other health issues such as poor muscle development, digestive issues, obesity, and heart complications.

Vaccines and Medications

A very common side effect of vaccinations is a loss of appetite. Though, this loss of appetite is only temporary and should only last up to a day or two. If you notice that this loss of appetite is lasting for several days, then you should see your vet.

Image showing a dog at the vet

You may not be able to figure out if your dog is suffering from stress or a sickness, so, we do recommend that you go to your vet to make sure there’s nothing physically wrong with your dog.

So, now that you know what an underweight dog looks like and why your dog may be underweight, let’s look at how to fatten up a skinny dog.

How to Fatten Up a Dog

Here are 8 ways to help you add some weight to your dog. Now, we highly recommend you do get your dog checked by a vet first, just to make sure their inability to gain weight isn’t connected to any underlying factors such as illnesses. However, if your dog has no underlying conditions, here’s what you’ll need to do in order to help your dog gain some weight:

  1. Set a goal
  2. Change your dog’s diet
  3. Change your dog’s mealtime
  4. Add calorie-dense ingredients to their meals
  5. Don’t forget the supplements
  6. Praise them when they finish eating
  7. Keep your dog in a stress-free environment
  8. De-worm your dog
  9. Be patient

Set a Goal

What is your goal? It’s important to have a goal in mind when you’re trying to fatten up your dog. If you choose to consult a vet, they’ll be able to tell you the weight your dog needs to reach in order to be healthy.


From there, through food and daily care, your dog should be able to gain weight successfully. But, do keep in mind regarding how much weight they need to gain and the length of time it takes to gain it. That way, if they do not gain the weight in that specific time period, you’ll be able to look at why.

Change Your Dog’s Diet

This is one of the most important things to do in order to help your dog gain weight. You’ll need to raise their caloric intake as well as change the food they’re eating. Perhaps your dog is disinterested in their food because it’s become repetitive and boring.

Image showing a person feeding a dog

Thus, you’ll want to introduce not only a tastier food but also a healthier one that’s packed with protein and necessary minerals and vitamins. That way, when they eat, they’ll be given proper nutrition.

Change Your Dog’s Mealtime

Many owners make the mistake of leaving their dog food in their bowl the entire day. This doesn’t entice your dog to eat more, in fact, it actually lessens their desire to eat more. Instead, what you want to do is time your dog’s meals so that a pattern starts to develop. If you feed them every day at 5 pm, their stomachs will start to be hungry every day at 5 pm — it becomes a regular routine.

Image showing a person feeding a dog

You’ll want to make sure you build this routine for both meals, one in the morning and one in the evening. If you’re unsure how much food to give your dog, there are recommended portions on the back of the packaging or you can ask your vet.

Add Calorie-Dense Ingredients to Their Meals

Maybe your dog is simply a picky eater and if that’s the case you’ll have to be adding extra nutrients into their dog food. So, focus on foods which they’re allowed to eat and also supply them with extra protein and vitamins.

Image showing a dog eating yogurt

You can put tuna, yogurt or corn oil into their food. You can also cook chicken or beef and mix it into their dry food as well. This shouldn’t act as a meal replacement, but rather as an add-on to their dry food. Dogs are smart, so it’s easy for them to become spoiled.

Don’t Forget the Supplements

Yes, you can buy supplements for your dog. Providing your dog with proper supplements will help your dog gain mass. Vitamins such as vitamin B help to metabolize and break down fats, proteins and carbs. Once your dog is feeling energized, the appetite will increase and the fat will convert into muscle.

Praise Them When They Finish Eating

Some dogs have anxiety when it comes to eating. If your dog seems to be shy when mealtime comes around, give them a helping hand. You can physically hold food in your hand while they’re eating, to make them feel relaxed.

Feeding hungry labrador retriever. The owner gives his dog a bowl of granules.

The important thing is to make sure you praise them during meal time. They may not eat the entire bowl of food on the first day but little by little, they’ll eat more and more. You need to show positive reinforcement through encouragement.

Keep Your Dog in a Stress-Free Environment

Your goal is to get your dog to eat more, thus, to gain more weight. Just like humans, stress can greatly affect a dog’s appetite. If you’re concerned about the weight of your dog, then you need to look at the living conditions your dog is currently in. Does their environment impact their stress levels? If so, then this needs to change. You want to make sure that your dog is living in a clean and spacious area where it can sleep comfortably.

Image showing four happy dogs

In addition, you also need to make sure that your dog is getting enough time outdoors. If you think that making sure your dog exercises is counterproductive, think again. If you want your dog to gain muscle rather than fat, then exercise is exactly what they need. Plus, if they’re in stress, walking or going for a run will help reduce those feelings.

De-Worm Your Dog

It’s very important to regularly de-worm your dog. Why? Because worms that live inside your dog’s digestive system absorb the nutrients that should be given to your dog.

You may be surprised to find that the reason for your dog's lack of appetite or recent bloating is due to worms

If you notice that your dog’s appetite hasn’t changed, yet, it’s losing weight, then you should ask your vet to prescribe you a de-wormer. If your dog gains weight after the de-wormer and everything goes back to usual, then you’ve solved the underlying condition.

Be Patient

This isn’t going to happen overnight. Though you will see progress within a couple days, you must be patient. If you’re not noticing a change in their behavior or that they’re losing more weight, then you need to see a vet as soon as possible. Weight loss and a lack of appetite are further indications that there is an underlying condition that needs to be treated.

Wrap Up

It’s important before taking measures to fatten up your dog to ensure that there are no underlying health conditions. Make sure you consult your vet about your dog’s weight as they’ll be able to take into consideration the breed and size of the dog.

If your dog is underweight and any health conditions have been treated, then you’ll be able to take the necessary steps in helping your dog gain weight. Make sure you use high-quality food, keep a regular meal schedule and add caloric-dense ingredients into each meal. Weight gain isn’t going to happen overnight, so, you’ll need to be patient, however, within a couple of weeks you’ll notice a change in your dog’s appetite and weight.

Image showing a person weightening a dog

Now that you know what causes weight issues, how to identify if your dog is underweight and the steps needed to increase your dog’s weight, it’s time you took action. Being under or overweight are both unhealthy lifestyles for your dog to be living.

Do you plan to use any of these tips we provided for you above? If your dog has struggled with weight gain before, what technique did you use to manage your dog’s weight? Let us know in the comment section below!

About the author
Wyatt Robinson
Wyatt Robinson

Wyatt Robinson had a great 25-years career as a veterinarian in United Kingdom. He used to be a member of British Veterinary Association and worked in 3 pet hospitals in London and Manchester. He is shining when he sees his pets healthy and full of energy and it is his duty to help other dog owners to keep their best friends full of life.