Skip to Content

How To Make A Guinea Pig Gain Weight? (the healthy way!)

Many guinea pig owners question whether their cavies are a healthy weight. If you pick up your guinea pig and feel protruding ribs or spine, then they may be underweight. 

An underweight cavy is an enormous concern and could lead to serious health problems or even death. It is crucial to ensure they are at a healthy weight and help them gain weight if the need arises.

You must first determine what is causing the weight loss with a vet visit, then make a nutrition plan to include a variety of fresh vegetables, unlimited hay, and pellets.

Continue reading to understand why the weight of your guinea pig is so important and what you should do to give your guinea pig that extra boost to gain weight.

Why is weight so important to your guinea pig? 

It is essential to know how much your guinea pig should weigh at every stage of its life. 

An adult cavy will weigh much more than a newborn pup, and a female may differ in weight from their male counterparts. 

The weight can also determine if the guinea pig is in good health. If the cavy has any health problems, a low weight may be the only sign that something is wrong. 

Underweight guinea pigs have a high mortality rate, and low weight can cause your cavy to have no energy to function.  

Feeding the right food, weekly weighing, having social interactions, and a clean environment all play a factor in your guinea pig’s weight. Knowing what to feed your guinea pig is just part of the solution. 

To maintain this weight, you will have to keep an eye out for illnesses, and keeping a record of their weight can help determine when this illness could have started.  

Throughout this article, you will read tips on what you should have within their diet and what health problems could affect your cavy’s weight. 

Weigh your guinea pig weekly to catch illnesses early. It could save your guinea pig’s life.   

How to help a guinea pig gain weight?

How to help a guinea pig gain weight?

A simple change in diet could help your guinea pig gain weight, but hand-feed with Critical Care for severe cases. We should introduce any new foods slowly to avoid digestive issues. 

Hay and pellets should always be available, and you may need to look for foods with higher calcium and vitamin C. If your cavy is prone to kidney or bladder stones, limit foods with oxalate.

Critical Care for severe cases

Critical care is a nutrient-dense product that you mix with water to make a paste. 

You can make your own critical care at home for emergency rations by grinding pellets up in your food processor for only a few seconds. 

Mix with water, add mashed-up fruits and vegetables to increase nutrients, and then use a wide syringe to feed your cavy. 

If liquid Vitamin C is needed, make sure you put it directly in your cavy’s mouth. Weigh and feed your guinea pig multiple times a day during this critical time. 

Interesting READ  Why Do Guinea Pigs Eat Their Babies?

Main Nutrition

Unlimited hay, a variety of fresh vegetables, and pellets every day are a must. 

Alfalfa hay is better with an underweight guinea pig because it is higher in calcium, carbohydrates, vitamin C, fiber, and protein. You can change pellets into alfalfa-based as well. 

Each guinea pig should have a cup of veggies each day. A low-weight guinea pig may need extra feedings, but most prefer to provide foods with higher vitamin C and calcium. These vegetables include:    

  • High in vitamin C: red peppers, parsley, mustard spinach, kale, broccoli, green peppers, and brussel sprouts.
  • High in calcium: lamb’s quarters, mustard spinach, dill weed, turnip greens, dandelion greens, collards, parsley, and kale.
  • Other favorite veggies (do not feed iceberg lettuce): coriander, kale, chard, romaine lettuce, cucumber, and celery. 


We should reserve treats once or twice a week, as they contain sugars that can cause other health issues. Fruit treats include:

  • High in Vitamin C: kiwi, papaya, strawberries, orange, lemon without the peel, cantaloupe, grapefruits of white, pink, and red, tangerine, lime, and mango. 
  • High in calcium: seedless raisins, orange, lime, blackberries, kiwi, lemon without the peel, papaya, and raspberries.
  • Other fruits favorites: bananas, tomatoes, apples with the skin, strawberries with the green top, and blueberries.   

What to take note of when helping your guinea pig gain weight? 

There are three things to note when helping your cavy gain weight: a physical check, weekly weigh-ins, and a safe environment. 

A physical check can help you determine if there is an injury that could cause the weight loss. A weekly weigh helps to know the average weight of your guinea pig and when to be alarmed. 

Finally, check often to ensure the environment is safe with no hazards.

Physical Check

Check over your guinea pig each time you pick them up. A guinea pig should have bright eyes, clean eyes and nose, and a healthy-looking coat and skin. 

Any crustiness, lumps, diarrhea, and different behavior problems will need to be managed appropriately. Make a list of other symptoms to look for when looking over your cavy. 

Is your pig lethargic and not eating on its own? This is serious, and a vet visit is to rule out any underlying conditions. 

Familiarize yourself with any other signs of illness and check for bites or lacerations on the body and inside the mouth that need to be tended to. 

Any labored or wheezing breathing, dull or crusty eyes, or unusual behavior needs to be addressed. When in doubt, see your vet.

Weekly Weigh

Cavies can decline rapidly, so the best way to know your guinea pigs’ weight is to weigh them weekly. 

Make sure you record the weight of your guinea pig every day, multiple times if you need to monitor the situation, and make sure they don’t continue to lose weight. 

Any continued weight loss needs to be checked by a vet as it could be a sign of illness.

Safe Environment

Check your guinea pig’s environment to ensure it is a safe place to be. Make sure there are only guinea pig safe huts and hides that won’t harm them if they chew on them. 

Separating your guinea pig during feeding times can help you see just how much your cavy is eating. While guinea pigs are social creatures, there could be some that may hog food. 

Interesting READ  Can Guinea Pigs Eat Pine Needles?

Bites and lacerations can really harm your guinea pig, so any guinea pig housed together must be compatible.  

What are some health problems relating to low weight?

What are some health problems relating to low weight?

Weight loss is often the first sign to tell you something is wrong. It could also be the only sign, so you must be observant. 

In the wild, guinea pigs are prey animals, so by instinct, they hide their illnesses so as to not attract predators. 

We should know what illnesses could affect our guinea pig’s health. Bites, poisoning, or infections are some illnesses that can present with low weight and would need to be treated by a vet. 


Anorexia is a broad term defined as not eating any food, and there is usually an underlying cause that needs to be resolved. 

Many things, such as changes in temperature, diet, dehydration, or even depression, could cause anorexia. 

Guinea pigs are social creatures, and having a compatible playmate can help to ease depression. 

Pain could also be a trigger for a guinea pig to stop eating, such as pain in their mouth or throughout their body.


Malnourishment is when the guinea pig is not getting the proper nutrition within its diet. 

They need fresh vegetables high in vitamin C to live a happy life. A guinea pig needs one cup of vegetables, pellets, and hay every day.  


Overgrown teeth or malocclusion can cause an immense problem as their teeth continue to grow throughout their lifetime. 

The overgrown teeth can make it hard to chew and eat food. Therefore, unlimited hay is a must and needs to be always available.  


Scurvy is the lack of vitamin C. Guinea pigs can’t produce their own vitamin C, so they must receive it in their foods. 

Red peppers are an all-time favorite for guinea pig owners and a cheap option to give every day.

What is the ideal weight for a healthy guinea pig?

The average guinea pig should weigh between 900-1200 grams for males and 700-900 grams for females. An infant guinea pig should weigh around 70-100 grams. 

You will want to weigh the baby often to determine that they are growing, and once the weight is maintained over a period of time, then you could consider this as their average weight. 

It is essential to determine your guinea pig’s normal weight so you can catch any weight loss before it becomes a big problem. 

Being 85-100 grams under their normal weight is a significant cause for concern, and action needs to be taken. 

Weighing your guinea pig weekly can help you keep track of any sudden weight loss, and most people have the supplies on hand in their kitchen to weigh their cavies. 

A kitchen scale that measures in grams is the best way to see just how many grams your guinea pig weighs. Weighing in grams is better than ounces because you can see minute changes in weight. 

Placing a box on the scale can help contain a runaway guinea pig, but make sure you zero the scale before placing your cavy inside.