Guinea pigs, like other pocket pets, need soft, absorbent bedding for their cages. A good product keeps the cage dry and odor free in between cleanings, which should be done at least once a week. If you spot clean by taking out soiled bedding in between full changes, your pet will have a pleasant, healthy environment.
Wood chips used to be the most common bedding choice for guinea pigs, but now many pet owners are using paper-based bedding, or even fleece. All three common bedding types have their pros and cons.
Years ago, small animals like guinea pigs were bedded on wood shavings and kept in aquariums. Today, we know that aquariums are too small and don't provide adequate ventilation. We also know that certain types of wood chips, and cedar in particular, have oils that can make guinea pigs and other small animals sick.
Some cavy owners still use wood chips. The usual choice is pine, since the kiln dried variety is safe. Personally I don't like wood chips for several reasons. First, I don't find them to be very absorbent or to offer much odor control. When I adopted my guinea pig, Amy, via Craigslist, she came in a small cage lined with wood chips. Her preferred potty spots smelled awful, and the chips in those areas were soggy.
The second big problem was that the chips sent me into an allergy attack. I had to immediately change her bedding for that reason alone. Guinea pigs can also be allergic to their bedding materials. With these potential pitfalls, I recommend avoiding wood.
Various manufacturers are making small animal bedding out of paper. Even though they're made from the same basic material, the brands differ widely in texture, absorbency, and even the amount of dust. Some brands come in different colors, while other are white or have natural coloration. Manufacturers typically pack paper bedding tightly, so it expands when you put it in your guinea pig's cage.
I use paper bedding for both of my guinea pigs, who are in extra-large pet store-bought cages. I prefer Carefresh because it's not messy, and the white type makes it easy to find and spot clean soiled areas. However, I also like Kaytee Clean and Cozy, or rather my guinea pigs do, because it's extremely soft, even though its light weight allows it to fly around.
Paper bedding is more expensive than wood chips, but I find its absorbency and odor control to be far superior, and its limited amount of dust doesn't trigger my allergies. Unlike wood, there are no potential health hazards to guinea pigs. This makes it well worth the additional cost
Fleece is a relatively new entry into the guinea pig bedding arena. It's primarily used with homemade cages built from corrugated cardboard and storage grids. This configuration allows cavy owners to customize their cages and ensure that their pets have plenty of room. The fleece is soft and absorbent if pre-treated correctly and if a proper under layer is used.
Besides the softness, which most guinea pigs love, fleece bedding is less expensive than other types in the long run, since it's reusable. This also makes it more environmentally friendly than disposable options.
Many guinea pig owners who use fleece get very creative with the color scheme in their cages. If you're handy, you can even sew matching accessories like tunnels, cuddle cups, and beds for you cavies, made from the same or matching fleece. I'm not at all handy, so I buy things like beds pre-made for my brood.
I don't use fleece, since I've still got my guinea pigs in store-bought cages rather than C&C homes (the abbreviation stands for Coroplast and cubes, with Coroplast being the brand name for the special cardboard and cubes being the storage grids). However, it's the best choice if you have a C&C cage.