Once it’s fully grown, you should not notice your chinchilla gain weight over time. Experienced owners say this is almost impossible, but if your chinchilla overeats, surely it is?

Can chinchillas get fat? They can; chinchilla weight gain is caused by fatty treats like nuts or seeds. Lack of exercise can compound the issue, although some chinchillas are larger because of genetics. To help a chinchilla lose weight, feed it a suitable diet of hay and give it more exercise, e.g. in a pen. Consult a vet and they can tell you what your chinchilla’s weight should be.

As the owner, your pet’s health is your responsibility. Follow our guide below to learn how to tell when a chinchilla is overweight, what a suitable diet is, and how to help it lose weight if it’s fat/obese.


Is My Chinchilla Fat? (How to Tell)

Chinchillas in general do not get fat, provided they are cared for correctly. There are several reasons for this:

  1. Chinchillas are exotic pets, not starter pets. As such, their owners are typically older and better at caring for pets than average owners.
  2. Chinchillas eat hay. Hay is low in calories and high in fiber, so even if your chinchilla eats lots of it, it will not gain weight.
  3. Chinchillas are naturally active. A basic cage setup provides for this as it contains platforms the chinchilla can jump to and from.

Because of these reasons, highly overweight or obese chinchillas are rare. But that doesn’t mean it’s impossible for one to get fat. You can spot whether yours is overweight through the signs below.

Sign 1: How Much Should My Chinchilla Weigh?

Likely the first thing you’ll think to do is weigh your chinchilla. This is not a bad idea, but it’s also not entirely accurate in every case.

That’s because the average chinchilla weight depends on both the individual pet’s sex and species. Females are larger than males on average, and short-tailed chinchillas are heavier than long-tailed ones. Also, an individual chinchilla can be larger than others because of its genetic make-up. So:

  1. Long-tailed chinchillas weigh between 370 and 490g
  2. Short-tailed chinchillas weigh between 1.1kg and 1.4kg (one kg is 1000grams, so short-tailed chinchillas are heavier)
  3. Females approach the heavier end of these scales, while males approach the lighter end

As such, weighing your long-tailed chinchilla and finding that it’s 600g (slightly heavier than average) isn’t enough to tell you whether it’s an unhealthily large weight. This individual chinchilla could be large because its genetics cause it to be, rather than overeating.

Sign 2: What Does an Overweight Chinchilla Look Like?

It’s difficult to spot whether a chinchilla is fat or not. As they have such dense fur, they look like overweight puffballs even if they aren’t. So, the fact that your chinchilla looks large is not proof enough.

There is a test you can perform to see if your chinchilla has more fat reserves than normal, however. This involves a particular way of holding your pet:

  1. Pick your chinchilla up according to approved guidelines
  2. Place your hands gently on either side of your pet’s chest, i.e. directly under its ‘armpits’
  3. Hold your pet supporting it only under its armpits

Then, look at your hands. Does your chinchilla have fat rolls which sit over your fingers? If so, it may be overweight. You can both see and feel these fat rolls if they’re present, but don’t mistake small amounts of loose skin for them. This is not a fool-proof method, but it can help you compare your chinchilla to others in a way that doesn’t rely on measured weight.

Sign 3: Chinchilla Eating Too Much

If you notice your chinchilla overeating, that isn’t necessarily a problem. A pet chinchilla’s diet should be roughly 80% hay, and hay is not a nutrient-dense food. Hay is high in fiber, but low in protein and fat. This means that your chinchilla has to eat lots of it to survive.

What this means is that a chinchilla on a suitable diet cannot overeat. You can ‘free feed’ your chinchillas, which means giving them an unlimited supply of hay that they have access to at all times. They will not become severely overweight.

What will make your pet overweight is if you feed it too many treats. Nuts and seeds are full of vitamins and minerals, but are also high in calories compared to a chinchilla’s regular food. So, if you feed your pet treats all the time, it may become overweight.

Sign 4: Chinchilla Isn’t Exercising

Chinchillas are active animals which require exercise. You should notice your chinchilla frequently scampering and jumping around its cage. And, when you take your chinchilla from its enclosure, it should get excited and want to run around as fast as it can. If it’s not, this is a bad sign, and it’s bad for your pet’s health too.

A lack of exercise likely won’t cause weight gain alone, but can make the effects of a poor diet even worse.

This exercise can be provided either inside or outside of the enclosure. Ideally, your chinchilla should have the means to exercise on its own rather than relying on you. As such, a chinchilla’s exercise requirements are best met inside the cage, e.g. with an exercise saucer.

So, if you notice that your pet is hardly moving, this could be one of the issues behind its weight gain.

Sign 5: Gut Problems (Not Going to the Toilet)

Chinchillas can experience a condition known as ‘gastrointestinal stasis’, also known as ‘GI stasis’ or simply ‘stasis’. The normal emptying of the stomach and passage of food through the intestinal tract is slowed down until it eventually stops. This occurs alongside gastrointestinal dilation, which is where ingested items accumulate in the stomach, intestines and cecum.

These issues are caused by poor diet, and can result in temporary weight and size gain. Your chinchilla may go through stasis if its diet contains inadequate amounts of long-stemmed, coarse fiber (i.e. hay).

There are several signs of stasis which you can observe:

  1. The chinchilla will first stop eating its core diet (hay). It may persist in eating treats for a time, although it will stop eating these, too, eventually.
  2. Fecal pellets are smaller and are passed less frequently. Alternatively, diarrhea may occur.
  3. The chinchilla becomes bloated as food and gas accumulate in its stomach and gut.

This won’t cause ‘weight gain’ in the sense that overeating does. Your chinchilla won’t put on fat reserves because of stasis. But its weight will be higher because it isn’t expelling waste as it should.

If you suspect that your chinchilla is experiencing stasis, take it to the vet. The vet can identify the underlying cause and fix it for you.

Consult a Vet

If you still aren’t sure whether your chinchilla is overweight or not, talk to a veterinarian. If possible, pick a vet who specializes in small and/or exotic animals, as they will have more experience with chinchillas than the average vet.

The vet can do two things. First, they can tell you whether your chinchilla is larger than average. Using accurate scales and measurements, as well as accurate guidebooks, they can figure out how far above an average size your pet is.

But more importantly, the vet can tell you whether your pet’s excess size is making it unhealthy or not. As stated above, large size is not strictly indicative of poor health. So, the vet can perform several non-invasive checks to assess your pet’s overall health and recommend any changes that may be necessary.


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How to Help a Chinchilla Lose Weight

If your chinchilla is overweight, a vet would recommend one of two core solutions: have your pet consume fewer calories, or burn more calories. This means adjusting your pet’s diet and giving it more of a chance to be active.

1. Offer Approved Treats, Not Nuts and Seeds

The only reliable way in which a chinchilla can become overweight is if you consistently feed it the wrong foods. If you feed it pellets formulated for other rodent pets, for example, or if you feed it nuts and seeds than it can get too much fat and protein. This would lead to it growing in size.

Instead, stick to an approved diet. Your chinchilla’s diet should be at least 80% (4/5ths) hay.

Chinchillas do not need variety in their diets like other animals do. But if you do plan on giving your pet treats, only give it fresh vegetables. These are low in protein and fat, which your pet doesn’t need much of. If you have your chinchilla overeat fresh vegetables, weight gain is impossible, although diarrhea may occur.

2. Encourage More Exercise

Exercise burns calories. So, if your chinchilla has lots of excess fat, excercising is the best way to get rid of it.

There are three ways in which chinchillas exercise. The first is if you provide yours with platforms in its cage to jump up and down from. Chinchillas enjoy jumping, which is why they will run around and jump excitedly when happy. Installing platforms at different levels in your pet’s cage provides a bare minimum of movement and exercise for your pet.

Rodent pets are also commonly given exercise wheels. These allow rodent pets to reach full running speed, which is something they cannot otherwise do in a cage. This is the ideal exercise as it mimics the pet’s natural routine of regularly running, and so is essential for good health.

Unfortunately, regular wheels are not suitable for chinchillas. There are several reasons why:

  1. The majority of exercise wheels are too small. It is difficult to find ones of the right size.
  2. Due to their size, they bend a chinchilla’s back at a dangerous angle at which bone fractures are possible.
  3. Chinchillas can catch their feet in the gaps between the wires of a wheel. This, too, can result in fractures.

Instead, experienced owners recommend the ‘chinchilla saucer‘. This is like a flattened metal bowl that spins around like a frisbee. Chinchillas can run on them at full speed and in a natural posture.

The third way of exercising your pet is to allow it outside of its enclosure, in a pen or a chinchilla-proof room. But however your pet exercises, doing so is good for its health.

3. Monitor Its Weight

You must weigh your pet consistently to tell whether your efforts are having an effect. This is a quick and easy process if you have all of the equipment available, and your chinchilla is comfortable with handling. Begin with a pair of digital kitchen scales. These can be found in any homeware store. Then:

  1. Take a bowl and weigh it. Cancel off the weight of the bowl so that you can weigh what you put in it, rather than the weight of the bowl plus its contents. There is normally a button that does this for you.
  2. Place the chinchilla in the bowl. If your chinchilla will not sit still in the bowl, use a box with a lid. Poke a hole in the box if necessary to ensure that your pet gets enough air.
  3. Note down your pet’s weight in a book. Update the book every other day with your pet’s weight to monitor its weight changes.

Once your pet’s weight is back within a healthy range, continue to monitor it for a period afterwards. Just as worrying is for a chinchilla to be underweight. But if you are providing a suitable diet and encouraging enough exercise, your chinchilla’s weight loss should peter out once it’s healthy again.

4. Talk to a Vet

Throughout this process, the vet is your friend.

An initial consultation would help identify what’s wrong with your pet. The vet could see if there are any underlying causes of the weight gain, e.g. illness. They can also tell you what a healthy weight would be, and how to help your chinchilla lose weight until it weighs that much.

Then, afterwards, the vet can still help. Once your chinchilla has lost some weight, you can ask the vet whether it is now healthy or not. The vet can also check whether your pet has lost too much weight.


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