How to Get a Rabbit to Gain Weight?

If you have an underweight rabbit, there are a few things to consider as you try to bring it up to a healthier weight. 

Once you’ve confirmed that your rabbit is underweight, there are a few strategies you can take that will naturally put more calories into your rabbit. 

So let’s go through the basic principles for getting your rabbit to gain weight.

Getting a Rabbit to Gain Weight: The Basics

If you’re looking to help your rabbit gain weight, there are a few steps you should take. 

First and foremost, bring your rabbit to a veterinarian. You want to be sure that there is no underlying health problem causing the weight loss.

Assuming that you’ve already gotten advice from your veterinarian, there are some easy dietary changes you can make at home to help your rabbit gain weight. 

Make these changes in addition to any treatment plans that your veterinarian has given you.

There’ll be more detail on each factor later in the article, but these are some of the main strategies that will help rabbits to gain weight:

  • Increase the amount of dry food you give.
  • Add fruit and root vegetables to your rabbit’s diet.
  • Feed your rabbit hay that has a higher caloric value.
  • Feed your rabbit dry pellets with high protein content.
  • Remove potentially stressful elements from their environment.
  • Remove limits on the quantity of dry food.

Whichever of these strategies you decide to try, just remember to go slow. It’s always healthier to change your pet’s diet gradually. 

Sudden changes can further stress your rabbit and might even end up having the opposite effect.

Also read: Why is my rabbit losing weight?

Make a Trip to Veterinarian

A trip to the veterinarian is a must.

Even if you have a hunch about why your rabbit is at an unhealthy weight, it is best to leave that judgment up to the professionals.

Since illness is one of the leading causes for a rabbit to be underweight, the veterinarian will be able to check for the following causes:

  • Dental disease: Because of modern breeding practices, rabbits can often develop various kinds of chronic dental issues.
  • Spurs: Molar spurs are sharp points/edges resulting from uneven usage of the teeth. The veterinarian can remove these to restore normal eating behavior.
  • Stress: Similar to humans, stress can cause unhealthy weight loss in rabbits.
  • EC: Encephalitozoon cuniculi is a rabbit parasite that can affect many different organs. They must be found with lab testing. 

If your rabbit is diagnosed with any of these conditions, follow the treatment plan given by your veterinarian. 

As directed by the doctor, you can also increase their caloric intake with some of the food outlined in later sections.

If your rabbit ends up getting a clean bill of health, you should assume the problem is dietary. Consider increasing its caloric intake with the following foods and strategies.

Rabbit Nutrition

As with most diets, rabbits need specific nutrients in the right amounts to be healthy.

Rabbits are herbivores, which means they get their nutrition from eating plants. 

Domesticated rabbits should try to mirror the diet of a healthy wild rabbit. The nutrients most important to rabbits include:

  • Vitamins 
  • Minerals 
  • Carbohydrates
  • Proteins
  • Fats 

In the wild, rabbits will usually find this variety of nutrition naturally by eating diverse foods. 

So, as the owner of a rabbit, you have to make sure that whatever diet you choose includes a balance of these nutrients.

In terms of balancing normal rabbit nutrition with gaining weight, keep in mind that rabbits eat less during the day and eat more at night

This statistic can help you strategize when to do a free-choice feeding where they get unlimited food until they naturally stop.

Increase Intake of Higher Calorie Foods

Putting medical conditions aside, the most obvious way to get a rabbit to gain weight is to increase its calories. 

You can increase your rabbit’s calorie intake by increasing the quantity of food or by choosing foods with higher caloric content.

Whatever path you choose, make sure to keep your rabbit’s diet balanced. Make significant changes only with the approval of your veterinarian.

High Protein Dry Pellets

Rabbits in the wild will eat various plant materials—roots, grains, green, and other roughage—which gives the right balance to their diet. 

However, domesticated rabbits are usually given dry pellets, mixed with the various food types, that give them balanced nutrition from one source.

Generally speaking, dry food pellets have a higher nutrition concentration, and they are one of the most accessible foods for rabbits to digest.

For a rabbit that needs to gain weight, do not use the standard adult pellets.

The standard adult pellets are low in protein and high in fiber.

So instead, use pellets higher in protein—the kind that is generally given to younger rabbits—which will give your rabbit more calories and a better chance at gaining some weight.

If any part of their diet can be unrestricted at this stage, it is the pellets.

Feed them unlimited pellets, along with their other food, so that weight gain can occur at a natural pace.

Fruits and Root Vegetables

In addition to dry food, many rabbits eat fresh food like leafy greens and other root vegetables.

Leafy greens are healthy and can be a great source of fiber, but they are not high in calories.

So if you want your rabbit to gain weight, consider introducing other vegetables, especially root vegetables, that tend to have more calories per unit. 

Give your rabbit carrots, peppers, and parsnip. You can also feed your rabbit certain fruits like apples and bananas in small amounts, which pack in many calories. 

Other fruits you can provide your rabbits include:

  • Blueberries 
  • Blackberries
  • Strawberries
  • Raspberries 
  • Cranberries

Since fruits (and certain vegetables) aren’t naturally in a rabbit’s diet, be sure to be mindful about keeping fruits and vegetables to a minimum. 

The majority of a rabbit’s calories should come from hay, grass, and pellets.

Feed High Quality Hay

Not all hay is created equal. If your rabbit needs to gain weight, you want to ensure that you are feeding it with the highest quality hay—hay with the highest calories and nutrition.

Fruits and vegetables can be a great way to get extra calories, but your choice of hay will more largely determine the nutrition of your rabbit. 

You should choose green hay that still retains a leafy quality.

Green hay is better than brown/golden hay. Green hay will provide your rabbit with the correct balance of protein and fiber. You just get more calories per unit consumed.

If your rabbit is picky about eating enough hay, you can also try fresh grass.

This is more akin to what they eat in the wild, and fresh grass will have a great nutrition value. 

Bigger Portions

Aside from these dietary changes in food types, you can also change your rabbit’s diet in terms of quantity. 

You should still be mindful about the changes you make and consult your vet before doing so, but there are certain foods that your underweight bunny can’t get enough of.

Grass/hay would be one of these foods. Rabbits in the wild mostly get their nutrition from green leaves, so feel free to be extra generous on this front as your rabbit needs more calories.

The primary way to give your rabbit more significant portions is with their dry pellets.

As mentioned, dry pellets are a concentrated source of nutrition—they’re a great way to jam-pack a lot of nutrition into a smaller amount of food.

An underweight rabbit should gain weight with unlimited pellets. This feeding style is known as free-choice feeding.

It means that endless amounts of food are always available to the rabbit.

You should not do this with all food, even with the higher protein pellets. With the standard adult rabbit pellets, you can be liberal in how much you feed your rabbit.

Why Is My Rabbit So Skinny?

There are a few potential reasons why your rabbit may be skinny.

One possibility is that he isn’t eating enough; make sure you are providing him with a variety of healthy foods and that his food dish is always full.

Another possibility is that he is not getting enough exercise; try incorporating some fun playtime into his routine to help him burn off some extra energy. This will also help their mood, diet, and overall well-being. Exercise is also a huge stress buster for rabbits.

A third possibility is that he may have a health problem, such as dental problems, gut inflammation, or even parasites; in this case, it’s best to take your rabbit to the vet for a check-up.

Whatever the cause, if your rabbit is noticeably underweight it’s important to take action and get him back to a healthy weight.

Things to Consider

As you consider what changes to make for your rabbit, there are a few things to consider.

Every rabbit is an individual, and not all recommendations will be best for your particular rabbit. 

So keep the following in mind as you try to fatten up your rabbit:

  • Underlying illness is often the root cause of weight loss in rabbits. Always go to a veterinarian first.
  • Stress can be a cause of weight loss in rabbits. If you think there might be things in the environment stressing out your rabbit, consider moving its cage and noticing what happens.
  • Make all dietary changes gradual. Sudden changes can make your rabbit sick.
  • Be conservative with how much fruit and root vegetables you give your rabbit as they are not natural to its diet in the wild.


Getting your rabbit to gain weight is simple. Feed them higher calorie food and feed them more of it.

If you do this while keeping their diet balanced, they should slowly gain more weight.

Also, keep in mind that weight loss could be a signal of a more significant health issue. So besides treatment, it’s best to ask your veterinarian about any new diet ideas before implementing them with your rabbit.

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