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10 Tips on How to Fatten Up a Dog

By: | Updated: October 26, 2019

Obesity is a main concern for many dog owners. But any weight problem can cause serious health consequences, including malnutrition. If your dog has become particularly underweight, it is important to know the safe and healthy ways to ‘fatten’ them up.

The key is to feed little and often while providing supplements to cover any dietary deficiencies. However, if your dog continues to lose weight despite eating food, has a sudden change in appetite, or seems generally unwell such as experiencing diarrhea, then seek your veterinarian straightaway. Regardless of the cause, it is essential to keep a dog’s weight in a healthy range to ensure a long and happy life.

While it can be a challenging task to get your dog to gain weight, this article will help you learn how to fatten up a dog safely and healthily.

Determining the Reason Behind a Dog’s Weight Loss

Picture of a beagle on a sofa.


There are many reasons why owners may want to learn how to fatten up a dog, and why a dog may find it difficult gaining weight.

If there is a logical cause why a dog is underweight, then fattening up a dog will be relatively simple. Perhaps your dog that has recently given birth or you have a rescue dog that has been mistreated.

Other reasons may include:

  • Multiple-dog household. If you have more than one dog then there may be a chance that other dogs are eating your underweight dog’s food. A simple solution is to feed each dog individually.
  • Illness. All types of illnesses can impair a dog’s ability to process food and take in the nutrients. Dogs experiencing illness are very likely to show signs such as decreased appetite, increased thirst, fatigue, vomiting or diarrhea. Conditions that commonly cause weight loss includes diabetes, liver disease, kidney disease and inflammatory bowel disease. So if you notice any of these symptoms, see your veterinarian immediately. After your veterinarian gives the all clear, you can begin to help your dog reach a healthy weight.
  • Stress. Dogs that are experiencing stress, anxiety or low mood may skip meals. It is not uncommon for a dog to refuse to eat after a traumatic event, recent life changes (such as being placed in a new home) or when alone.
  • Picky eater. Some dogs can be very choosy about what they eat. They only want the good foods and will not give in until they receive it! Your dog may also be fussy about the food brand, the food type, feeding location or feeding schedule. They might be bored of their standard kibble or dislike specific ingredients. In this case, find a food that works.
It is important to determine what is causing a dog’s weight loss. This will allow you to address the issue appropriately and promptly.

Is My Dog a Healthy Weight?

When attempting to find out a healthy weight for a dog, visiting a veterinarian is a good place to start. A veterinarian will also be able to rule out any issues that may have occurred through weight loss itself.

A healthy weight will vary across different breeds. Some have a naturally slimmer look such as Greyhounds, while others appear stockier like Pit Bulls.

According to Purina, dogs at a healthy and ideal weight should generally have an hourglass appearance. From above, a slight but visible narrowing around a dog’s waist should be seen. From the side, the tummy is tucked up from the chest. You should also be able to feel the ribs when placing both thumbs on a dog’s backbone and spreading both hands across the ribcage.

The video below explores how to determine a dog’s healthy weight by using a body condition score:

10 Tips on How to Fatten Up a Dog

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Now you have figured out if and why your dog is underweight, read more to find out how to fatten up a dog safely and healthily.

Have a plan in place before trying to fatten up your dog. Switching methods halfway through can confuse your pooch and disrupt their progress. You can visit your veterinarian to create appropriate weight goals for your pooch and plan how to achieve them.

1. Add More Calories to a Dog’s Diet

Unsurprisingly, the easiest way to increase a dog’s weight is by increasing the number of calories they consume. Small changes can create a huge difference over time.

However, fattening up a dog is not as simple as it may first appear and it can be tempting to go overboard. In reality, it is a delicate process that can easily end up in disaster.

For a dog to gain weight healthily, the process needs to start slow. Allowing a dog to gulp down a large quantity of food after going without as little as a number of days can lead to serious health issues such as refeeding syndrome. This occurs because the body feels incapable of experiencing such significant changes. It can cause consequences such as muscle weakness, respiratory failure and seizures.

Calculate how much your dog’s food allowance should be increased. As a rule of thumb, add no more than 10% of your dog’s current calorie intake. For a week, monitor your dog’s progress by checking their stool to make sure it is firm and healthy. If your dog is free of diarrhea, increase the calorie intake to a further 10%. Repeat this until your dog has reached a healthy calorie intake. During this process, monitor your dog’s progress by checking their stool to make sure it is firm and healthy.

Diarrhea may be a sign that you are overly increasing your dog’s calorie intake. Remember that a dog with diarrhea is losing valuable nutrition, and so your hard efforts have gone to waste.

2. High-Quality and Calorie-Dense Dog Food

The best formulas of dog food for promoting weight gain are made up of high levels of calories and protein. Select high-quality foods as these contain more nutritional value than cheaper alternatives. Cheap dog foods tend to be of poorer quality, created with artificial ingredients and contain inadequate amount of minerals, vitamins and fiber that a dog requires.

Opt for foods that contain real meat as the protein source such as beef, chicken, lamb or fish. This is because real meat contains more amino acids compared to by-products and meat meals. Look for products that have at least 20% or more protein content. Protein is particularly important when fattening up a dog for building muscle mass.

When shopping for a calorie-rich formula, take a glance at the ingredients list. Choose products with a higher kilocalorie amount, but be careful of foods with higher fat content. Too much fatty food can lead to excessive weight gain.

Your veterinarian may suggest feeding more than the recommended amount on the food packaging. In these cases, continue to do this until your dog reaches a healthy weight.

3. Food Supplements

Food supplements can be considered for not only increasing calorie intake but also to ensure your pup is receiving the nutrients they need. This is a brilliant option for picky eaters who can be enticed with a wet food topper. A popular option is by adding a scoop of wet or dog-approved gravy to the dry kibble for a boost of flavor and calories. If your dog still refuses the food, try switching to a different formula.

Consider adding foods that are rich in vitamin B such as eggs and meat. Vitamin B helps to increase a dog’s appetite and helps to break down the conversion of fats, protein and carbohydrates into useable energy. If you are considering vitamin B supplements, contact your veterinarian before adding any supplements to a dog’s diet.

Like with all diet changes, add new ingredients slowly to prevent any stomach upsets.

4. Feeding Schedule

Picture of a shar pei dog laying next to a watch.


Provide your dog with many opportunities to eat throughout the day. Divide your pooch’s daily feeding amount into 3-4 small meals throughout the day. This will help your dog to digest food easier and faster, creating a faster metabolism.

Try feeding your dog every four hours, and do not exceed over six hours between meals. A consistent feeding schedule will allow your pooch to become familiar with a new meal plan and develop into a routine. For you as the owner, it will make it easy to keep track of the amount of food they consume.

Alternatively, you can try leaving a daily serving of dry food out all day and allow your dog to eat whenever they feel hungry. This tends to work best with dogs with smaller appetites. It is not recommended with dogs that gulp food at an excessive pace. This is due to the problems associated with eating fast.

Introducing a new feeding plan will take time and patience. Remember that every dog has different needs. You might have to offer food in different forms or at different times. This will depend on when a dog feels hungry and how they react to a new routine.

5. Exercise

I know what you might be thinking. Why is exercise important to a dog that is underweight?

The answer is that underweight dogs need exercise to encourage muscle growth and increase appetite. Malnourished pooches tend to have underdeveloped muscles, so getting a dog moving will help them become stronger. As you have also increased their calorie and protein intake, they have all the energy they need to disperse into action.

As well as the physical benefits, exercise can have amazing mental benefits too. Providing dogs with lots of opportunities to run and play is a fantastic way to prevent stress and anxiety. Make exercise fun for both you and your companion by scheduling playtime and exploring the beautiful outdoors together.

Exercise should be introduced gradually to prevent injury.

6. De-worm Your Dog

All dogs should be de-wormed with a de-wormer medication. This is especially important as a preventative measure for underweight dogs. These parasites compete for food in the dog’s bowel, slowly extracting the food and nutrients out of your pup.

To learn more about worms and why it is important to de-worm your dog, read our article on how often to worm your dog.

7. Dental Care

Picture of a golden retriever dog chewing a toy.


Poor oral hygiene can contribute to a dog’s lack of weight. Aim to brush your dog’s teeth at least three times a week by using a toothbrush and toothpaste specifically made for dogs. Not only is this a preventative measure, but it also contributes to a dog’s overall health and freshens breath.

Dog dental chews are also great for keeping a dog’s teeth healthy. They remove plaque and tartar through the natural chewing process.

8. Maintaining Results

Once your pup has achieved their goal weight, it is equally important to equip them with the tools they need to maintain it. You can return their calorie intake to the recommended amount and start developing a more normal routine. For example, you may want to switch four small meals to two large meals a day.

You can continue to feed a high-protein dog food for weight gain as long as your dog is active and engages in regular exercise.

Carry on keeping a close eye on your dog’s weight and visit your veterinarian if the weight loss continues.

9. Health Awareness

By gaining a good understanding of your dog’s normal behaviors, you can easily identify when something is not right. Paying close attention and noting for any behavioral changes is a brilliant way to keep track of a dog’s presentation. This will be particularly useful if you need to inform your veterinarian.

10. Visit Your Veterinarian

Ultimately, it is important to contact your veterinarian before making significant changes to a dog’s diet and lifestyle. Regular visits to your veterinarian, maintaining preventative care and vaccinations are important for any dog’s health.

Final Thoughts

Picture of a dog on a beach.


Fattening up your dog does not have to be a challenging task. While it will be a slow road to recovery, your vigilance and patience will allow your pooch to live a long, healthy and thrilling life.

About the Author:

Serena is the content publisher for Daydreamdog and a life long dog lover. Between walking them, writing about them and spending too much time liking pictures of them on Instagram, her day literally revolves around dogs! If you want to learn more about Serena click here.