Why Does My Hamster Smell Bad?

Hamsters are a popular pet across the USA. They’re small, cute, and relatively easy to care for compared to larger pets like cats and dogs. However, they aren’t a low-commitment pet, and you need to make sure you keep an eye on any changes you notice in how your hamster acts or smells.

Your hamster likely smells bad because its cage isn’t clean. Hamsters are very clean animals and usually only smell if their cage is dirty. However, if your hamster smells bad, it could also be due to unclean bedding, something happening with its diet, poor airflow in the cage, or health problems.

Throughout this article, I’ll go into detail on the most common reasons why your hamster might have started to smell bad. I’ll also give you a good idea of how your hamster should smell. Keep reading to find out more!

How Should Your Hamster Smell?

To start this article, let’s look at how your hamster should smell normally.

Hamsters are small domesticated rodents that are often kept as pets.

However, since hamsters are part of the rodent family, some people, especially people in big cities like New York where mice and rats are a concern, might have the misconception that they are inherently dirty or smelly animals.

That couldn’t be further from the truth.

Contrary to popular belief, hamsters are incredibly clean animals and often groom themselves.

Because they’re frequent groomers, hamsters don’t usually have a smell that you can notice from any distance. If you snuggle your hamster, you might notice an odor that is a mix of musk and bedding because all animals have some sort of smell.

However, this scent should be mild and really only perceptible at a very close distance.

A strong smell is typically a sign that something is wrong and shouldn’t be ignored or thought of as “normal.”

why does my hamster smell bad
why does my hamster smell bad

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Reasons Why Your Hamster Smells Bad

It’s completely normal to be concerned if you’re used to your hamster’s typical scent and you’ve noticed they start to develop a foul odor.

However, before you start jumping to worst-case scenarios of what might be causing the smell, it’s essential to know the main reasons for it.

Who knows, there might be an easy way to reverse your hamster’s bad odor and get your little friend back to smelling how it should.

Dirty Cages

Dirty cages and habitats are the primary reason why hamsters might start to smell bad.

This is especially the case for first-time hamster owners who might not know how often to clean out their hamster’s enclosure effectively.

However, even seasoned hamster owners can fall victim to improper cage care.

Even if you let your hamster roam around your home, it will most likely spend the majority of its time in its cage.

That means hamsters will be bathing themselves, rolling around in, and, yes, soiling their habitats every day.

Even though hamsters are clean animals and will likely pick one area of their cage to use as their toilet area, that will still cause an odor to build up, which will transfer to your pet hamster.

While that is the prime source of a smelly habitat, there are other causes of odor build-up on your hamster, including:

  • Your pet’s natural fur oils
  • Food and water that may have spilled
  • Dust or grime your hamster might pick up on its paws before it has a chance to clean itself

These will all contribute to an overall bad-smelling cage.

However, since your hamster will be in its cage most of the time, it’ll start to develop that scent as well.

This process is similar to how if you leave a cut onion in your refrigerator, everything in your fridge might start to develop that same onion smell.

Luckily, there’s an easy solution to this problem.

Make sure you remove any soiled bedding from the cage when you notice it.

You should also remove everything from your hamster’s habitat and deep clean it with pet-friendly surface soap and water every month.

A dirty cage shouldn’t cause your hamster to develop any foul odors if you follow these steps.

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If you’re using the wrong bedding for your particular hamster’s needs, that might also cause your pet to start smelling.

This can happen even if you clean your pet’s cage regularly.

You may not be using very absorbent bedding, which means that any odors from soiled bedding will start to build up faster.

You may be using scented bedding that just doesn’t mix well with your hamster’s natural oils.

Or you may be using bedding that starts to develop mildew faster in your particular climate. For example, bedding that might work fine in Arizona, where it’s dry, may not work in a more humid climate.

If you’re sure you are keeping your hamster’s cage clean but you still notice a smell, consider getting new bedding to see if that improves things.

I recommend looking for a bedding option that is both absorbent and fragrance-free, which should give you plenty of options.


Your hamster’s diet can have a huge impact on its scent.

Some hamsters may not be able to process certain foods efficiently, which can lead to a change in their odor, either by changing the scent of their natural oils or by changing the way their urine smells, for example.

If you’ve always noticed that your hamster has a bad smell, and you don’t think it’s a hygiene problem, then try to think about its diet.

Have you fed your pet the same food for the entire time you’ve had it?

If so, try changing to a different brand or type of food and see if you notice an improvement in your hamster’s smell.

If your hamster’s bad smell is a new development, have you changed its diet recently?

If so, does this diet change coincide with the time when you started to notice a negative difference in its smell, give or take a few days?

If that’s the case, try going back to the food your hamster ate before they started to smell bad, and pay attention to whether or not this helps restore their previous scent.

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Poor Airflow

You might have noticed that, no matter how clean a house might be, if the doors and windows are closed all the time, it will start to develop a musty smell.

The same thing is true for your hamster’s enclosure.

However, unlike a house that might need weeks or months before a smell starts to develop, your hamster’s home might only need a few days for it to begin to become a problem.

Your hamster’s cage needs to have ventilation so it can air out and smell fresh and clean.

Not only does airflow help keep your hamster’s cage from smelling stale and musty, but it will also help keep mildew or mold from growing where you can’t see it.

Even if you fully clean your hamster’s cage regularly, mold can grow quickly if you don’t allow ventilation.

Not only can this cause your pet’s habitat to smell, but that odor will transfer onto your hamster because the more time your hamster spends in a smelly environment, the more it will start to pick up that odor.

All of this will cause your pet to have an unpleasant scent as well. Not to mention, it can also lead to health problems down the line.

The best way you can prevent this and improve any poor odor problems caused by a lack of airflow is to make sure your hamster’s cage can ventilate adequately.

To do this, move the cage to an area of your home that’s draft-free but has a more regular flow of air.

You can also make sure that your hamster’s cage is able to air out when you let your pet roam around outside their habitat, so you won’t have to worry about your furry friend running away.

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Your Hamster’s Gender

This might come as a surprise, but the sex of your hamster might be the source of its smell. This is especially true if you would describe your hamster’s foul odor as “fishy.”

If you have a female hamster and they have a fish-like scent, then it might not be anything to worry about at all.

In fact, it might not even be something you can “fix,” as this is the one case when your hamster’s poor smell is entirely typical and should be expected.

Female hamsters will go into heat, which is the time frame when they would be able to get pregnant and then have babies.

This happens a few times a year for most animals, at most.

However, in hamsters, this happens every four days.

During this time, your female hamster can and likely will develop an odor due to hormonal changes occurring to them.

If you have a female hamster, here are a few things to consider:

  • Does her bad smell seem to happen often?
  • If so, does it go away but then come back?

If you think your hamster being in heat might be the cause of her bad smell, try to pay particular attention to her smell for about a week. 

If it seems like her smell gets better and then worse again on a four-day cycle, then this is probably a hormonal thing and nothing to worry you.

However, that also means there’s nothing you can do other than try to eliminate any other potential odor sources to mitigate the problem as best you can.

why does my hamster smell really bad
why does my hamster smell really bad

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Health Problems

If you’ve tried everything, but you still notice your hamster has a bad smell, then it might be time to call your veterinarian.

If your hamster is sick, then it may not be feeling well enough to clean itself, which will cause it to start smelling.

Other health concerns like infection or tooth decay can cause foul odors due to bacterial build-up and rot.

In any of these cases, you must take your hamster to a vet as soon as possible so it can start receiving any medication that might be needed to solve the issue before it gets worse.

Having a sick pet is always a cause for concern, but it doesn’t necessarily have to turn into a worst-case scenario if you pay a little attention.

If you notice your hamster has started to smell, then lookout for a few other signs that it might not be feeling well:

  • They don’t seem to clean themselves as often.
  • They seem sluggish, or they sleep more often than usual.
  • You notice them eating or drinking less.
  • You see droppings or urine all over the cage and not just in one specific area.
  • When you clean the bedding, you’ve noticed a change in their digestive habits that can’t be explained by diet.

While it’s not a guarantee that your vet will be able to fix what’s wrong with your hamster, having your pet looked at sooner rather than later will significantly improve its chances of making a full recovery.

Also, keep in mind that in most places, hamsters, though very commonplace pets, are considered “exotic animals.” This often means that regular veterinarians won’t see them. That’s why it’s important to seek out exotic pet vets near you before you ever bring your furry friend home from the shop or shelter.

Knowing who and where the nearest exotic vet is can make a world of difference in your pet’s life if you ever find yourself in a situation where a vet visit is warranted.

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It’s not normal for hamsters to smell bad. They’re very hygienic and love to groom themselves and keep their environment clean.

A hamster with a bad smell may not be the norm, but that doesn’t mean it’s automatically something bad. Usually, if your hamster has developed a bad smell, it means their cage isn’t being kept properly. However, a bad odor could also be coming from your hamster itself.

To get to the root of your hamster’s bad smell, ensure you’re keeping its cage clean, keep an eye on its behavior, and change the bedding and food you use.