Finding the right type of substrate, or bedding, for your reptile can be very difficult. Whether you are working with a tropical gecko or a desert lizard, it’s important to know what to look for. It has to be safe, free of dust, non-toxic, non-irritating, absorbent, and not likely to be eaten – or at least be passed through the digestive system if it is.
Some substrates that are good for one environment type are not necessarily good for another. Similarly, some bedding is good for one type, but dangerous for another. You need to know your reptile species!
When it comes to choosing a bedding, use common sense. Any brand of pet litter that advertises clumping or scoopable is going to be a problem – this includes corn cobs, clay litter, and any kitty litter, which often contains clumping agents like bentonite and silica. Things that clump will stick to tongues and get into food; once swallowed, they can wreak havoc on the intestines. Sharp particles can also get into the mouth or cloaca and cause irritation and infection. Skin irritation can also occur – although scales look tough, reptiles actually can have rather delicate skin. Pet litters are often very dusty and can cause respiratory issues.
Don’t use sharp rocks, such as un-sanded, rough lava rock, as decoration, and avoid stones and gravel altogether for bedding, as they don’t cushion falls for climbing reptiles and are not good for burrowing. You can use them for a drainage layer, but they can be heavy so be cognizant when putting together a naturalistic enclosure. Larger, smoother stones are best for decor.
There are many options when it comes to reptile enclosures. So while there isn’t always a definitive BEST substrate, there are some contenders for the WORST. Especially ones that are specifically marketed to reptile keepers despite known concerns voiced by hobbyists and vets.