What type of bedding is safe for my hamster?

When you're entering the world of #properhamstercare, it's important to understand that advice and guidance is regularly updated, so it's handy to stay on top of what is considered safe and what's not. Hamster bedding is a hot topic which is often under scrutiny, especially because many pet shops still stock unsafe materials, without stocking many safe materials.

So, what is the general hamster community guidance around safe bedding?

1. Fluffy bedding (Kapok pods, cotton wool, soft fibrous materials) are completely unsafe

2. Vague 'sawdust' products, and any cedar or pine wood shavings are completely unsafe

3. Paper or wood 'litter pellets' can be safe, but aren't recommended as hamsters cannot burrow through them

4. Scented beddings are completely unsafe and unnecessary

5. Plain, untreated paper bedding is safe

6. Hard wood shavings, including aspen, birch, and beech are considered safe

7. Wood 'chips' as opposed to shavings are unsuitable bedding/burrowing material

8. Some softwoods with non-toxic phenols, including fir and spruce wood are considered safe

9. In captivity, it's considered safer to keep hamsters in completely dry bedding materials to retain heat

10. Bioactive setups are not recommended

But what does the science say? This article will consider points 1 and 2, and we will release further information on the other points at later dates.

1. Fluffy bedding

   It goes without saying that this maintains its completely unsafe status. From Approaches to common conditions of the gastrointestinal tract in pet hamsters (2021), there is a disturbing image of fluffy bedding being removed in a post-mortem on a hamster. The study states that inappropriate bedding can lead to intestinal impaction and obstruction. In general, paper bedding is recommended.

2. Vague 'sawdust' products are also completely unsafe. Unless you can be sure which woods are in the product, you cannot be sure of its safety. Cedar has been proven to be unsafe in many studies, including The problem with pine: A discussion of soft wood bedding (1993), which states that cedar is unsafe because of increased incidence of respiratory problems, including pneumonia and suspected links to various forms of cancer.

What many do not realise is that many of these issues are prevalent in pine wood shavings also, due to the toxins contained in the wood. Pine and cedar alike contain toxic phenols, which are caustic, poisonous, acidic compounds present in softwoods. They cover the urine odour, making them a popular choice for years.

Since phenols are caustic, there's a direct and clear connection to respiratory problems, which hamsters are prone to according to Biology and disease of hamsters (2015). The 1993 study proves that the constant irritation to nasal passages, throat and lungs gives harmful bacteria an easy opening, which proves that this is a likely cause of internal infections. These phenols also affect organs such as the liver and kidneys because these organs are responsible for filtering blood and urine and eliminating toxins from them.

Pine wood has been found to be the second hepatotoxic bedding material after cedar. The laboratory animal community have recognised these concerns since 1967.

Because dwarf hamsters have been found to show a high prevalence of neoplastic disease according to Disease problems of small rodents (2002), and pneumonia is the second most common clinical condition in hamsters, it's incredibly important to take these concerns seriously and ensure that the bedding we're using is beneficial for their respiratory health.

But what about kiln drying?

Kiln drying is the process of drying wood in an oven. There is no set rules around this, including temperature or a specific desired moisture content.

In 'Distribution of low-molecular lipophilic extractives beneath the surface of air- and kiln-dried Scots pine sapwood boards' (2018), it was found that kiln-drying migrated the phenols around, meaning that they're more diluted than in woods which haven't been dried. This shows that, while it may reduce the toxicity of the woods, it is not enough to remove the risk entirely. It also depends on how long and the temperature of the drying in terms of its effectiveness.

So, when bedding packaging states that the wood has been kiln dried, there is no guarantee that it is any safer than in its raw format.