Is Corncob Bedding Safe for Your Small Pet?

Last updated:
Jun 11, 2023

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Choosing the right bedding for small pets is essential for their overall well-being. Among the numerous options available, corncob bedding has gained popularity due to its natural composition and absorbent properties. 

However, concerns have been raised about the safety of corncob bedding for small pets. In this article, we will explore both the arguments for and against using corncob bedding, shedding light on the potential risks and benefits.

Summary: Corncob bedding isn’t generally suitable as a primary substrate for small pets, but in small quantities, it can be used to offer a new texture for pets to explore. Corncob bedding shouldn’t be used for guinea pigs because it’s been known to cause digestive blockage. 

What is Corncob Bedding?

Corncob bedding is a type of bedding material commonly used in small animal enclosures and cages. It is derived from the inner core of corn cobs, which are the cylindrical structures that hold the kernels of corn. After the corn kernels are removed for various purposes, the remaining central core of the cob is processed and transformed into a bedding material.

To create corncob bedding, the cobs undergo a grinding or chipping process, breaking them down into smaller particles or granules. The resulting material is then dried to reduce moisture content and ensure a suitable texture for small pets.

There are two different types of corncob bedding: one that’s made for large animals like horses and one that’s made for small pets. The small-pet variety of corncob bedding is typically made of smaller pieces, while the large-animal variety contains larger pieces. 

Benefits of Corncob Bedding

There are good reasons why corncob bedding became a popular choice for small pet owners. 

For one, corncob bedding is typically free of chemicals and additives, making it a natural and eco-friendly choice for pet owners who prioritize sustainability.

Corncob bedding is the hardest type of bedding available for small pets, and it contains very little dust compared to paper bedding and aspen bedding. It has also been shown to reduce the spread of allergens and minimize the smell of ammonia. 

Learn more: Best Bedding for Mice

Concerns About Corncob Bedding

While corncob bedding offers various advantages, it is essential to be aware of certain concerns associated with its use. Pet owners should consider these potential risks and drawbacks to make informed decisions about the well-being of their small pets.

Digestive blockage

The primary safety concern with corncob bedding relates to digestive problems that can arise if pets ingest it. 

Small animals are naturally curious and may explore their enclosures by nibbling or chewing on various materials, including bedding. Ingesting corncob bedding can lead to blockages or intestinal obstructions, which can be life-threatening for pets. This is especially dangerous for guinea pigs, which have been known to try and eat corncob bedding. 

Fungal growth

Corncob bedding has the potential to retain moisture for extended periods, creating a favorable environment for fungal growth. If not maintained properly or changed regularly, the bedding can become a breeding ground for harmful fungi. 

This can increase the risk of respiratory infections or skin irritations in small animals. Ensuring adequate ventilation, practicing good hygiene, and replacing the bedding as needed can help prevent fungal growth and associated health issues.

Lowers humidity levels

The more absorbent a pet bedding it, the more it will decrease the ambient humidity inside an enclosure. Corncob bedding has been shown to be much more absorbent than other bedding types, which means it will reduce the humidity in an enclosure more than any other type. 

This can be harmful to many small pets if they’re in a low-humidity climate. In higher-humidity environments, corncob bedding may absorb moisture excessively, which will lead to increased fungal and microbial growth. 

Not suitable for burrowing

An important factor to consider for burrowing pets like gerbils, hamsters, and mice is whether or not a bedding or substrate is compatible with that behavior. These pets need to have the ability to create deep burrows that hold up and don’t collapse instantly. 

Corncob bedding isn’t suitable as the main bedding type for these pets because it will not hold up tunnels or burrows. 

Higher bacteria levels

In a study of bacteria levels in different types of small pet bedding, corncob bedding showed the highest levels of bacteria. High levels of these endotoxins can lead to health problems like lung inflammation and respiratory distress, and they generally decrease the quality of life of small pets.

Lower sleep quality

Corncob bedding has been shown to reduce slow-wave sleep (deep sleep) time in rats. This means that rats kept on corncob bedding get less deep sleep than rats kept on other types of bedding. 

This is probably because corncob bedding is less comfortable than other bedding types, meaning that rats and other small animals can’t get cozy enough for deep sleep.

Decreased deep sleep levels can lead to a host of health problems, from slowed healing and increased risk of chronic disease to emotional disturbances and impaired cognitive function.

Learn more: Best Gerbil Bedding

Uses for Corncob Bedding

Corncob bedding might have a lot of drawbacks, but it can still be useful for small pets. So if you already have a bag of corncob bedding, you might not need to just throw it out. Here are some ways you could still incorporate corncob bedding into a small pet’s habitat. 

Note: If you choose to use corncob bedding in your small pet’s enclosure, we recommend either freezing it for 48 hours or baking it to sanitize it.


Corncob bedding is super absorbent, so you could use it in litter boxes or areas of the habitat where pets are more likely to pee and poop (like corners).

Substrate boxes

Many small pet owners use a primary bedding type and multiple different additional substrates for their pets to explore. You can put these substrates in boxes or dishes to divide them from the rest of the enclosure. 

For example, you could use paper bedding for the deep layer of bedding in the enclosure, and then have several boxes or spaces filled with other substrates. Corncob bedding can be used in this way, offering a unique texture for your pet to explore.

Learn more: Torpor in Mice and Hamsters + How to Prevent It

Our Conclusion on Corncob Bedding

While corncob bedding has gained popularity as a natural and absorbent option for small pets, it is not generally suitable as a primary substrate. The safety concerns associated with corncob bedding, such as digestive blockage and fungal growth, make it a risky choice for small pets, particularly guinea pigs. Additionally, corncob bedding is not suitable for burrowing animals and may lead to decreased sleep quality and higher bacteria levels.

However, if you already have corncob bedding, there are alternative uses for it in your pet’s habitat. You can use it as a litter material in designated potty areas or incorporate it as a unique texture in substrate boxes or dishes, allowing your pet to explore different materials while still providing a safe primary bedding option.

It is crucial for pet owners to prioritize their small pets’ well-being by considering the potential risks and benefits of various bedding options. Consulting with a veterinarian and understanding the specific needs of your pet species can help in making an informed decision about the most suitable bedding for your furry friend.


  1. Leys LJ, McGaraughty S, Radek RJ. “Rats housed on corncob bedding show less slow-wave sleep.” J Am Assoc Lab Anim Sci. 2012 Nov;51(6):764-8. PMID: 23294881; PMCID: PMC3508179.
  2. Domer DA, Erickson RL, Petty JM, Bergdall VK, Hickman-Davis JM. “Processing and treatment of corncob bedding affects cage-change frequency for C57BL/6 mice.” J Am Assoc Lab Anim Sci. 2012 Mar;51(2):162-9. PMID: 22776115; PMCID: PMC3314518.
  3. Whiteside TE, Thigpen JE, Kissling GE, Grant MG, Forsythe D. “Endotoxin, coliform, and dust levels in various types of rodent bedding.” J Am Assoc Lab Anim Sci. 2010 Mar;49(2):184-9. PMID: 20353693; PMCID: PMC2846006.

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LittleGrabbies is an independent blog run by one human and her pets. We want to help you sift through all of the information that's out there for small pets to provide the best possible care.


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