Many of the ready-made cages sold in pet stores are not suitable for guinea pigs—despite the fact they are advertised as being so. Most of them are too small and some even have wire grid floors—which should never be used to house guinea pigs.

Bigger is better! For the health and well-being of your guinea pigs, provide as large a living area as you can manage. Cage size standards are listed below. Following these standards will result in happier, healthier, and perkier guinea pigs.

• DO NOT buy a wood hutch like those sold by Trixie
  Wood hutches do not have adequate ventilation due to having a solid back wall and an area completely enclosed by wood. Additionally, wood hutches may become and stay wet (since wood takes a longer time to dry than plastic) if the guinea pigs pee on the wood and resultantly, bacteria may grow.
• DO NOT use an aquarium or plastic storage tub as a cage
  Aquariums don't provide adequate ventilation. Likewise, plastic storage tubs with sides higher than 6 inches don't provide adequate ventilation. Without adequate ventilation, the guinea pigs can develop respiratory issues.
• DO NOT buy a cage with a wire floor
  Guinea pigs have sensitive feet. Walking on a wire floor can cause serious health issues to form over time, such as bumblefoot.
• DO NOT buy a multi-story cage
  Guinea pigs are fragile. A fall from any height can result in serious injury. A single floor cage is best for this reason. If you buy a second level, the ramp must have sides and the second level must have a walls on all sides to prevent a jump or fall.
• DO NOT buy a cage smaller than 7.5 sq ft
  Guinea pigs thrive best when they have a friend of their own kind to share a cage with. To have adequate space to move about, they will need at least 7.5 square feet of ground floor space regardless of the amount of floor time provided. More cage space is always better.
• DO NOT count upper floor space in total cage space
  Guinea pigs are ground animals. They enjoy running laps, aka zoomies, and need ground floor space in their cage to perform them whenever the mood strikes.
• DO NOT use a physical divider
  Some cages come with a divider to partition the cage into 2 parts with a small doorway separating the two parts. The divider makes it impossible for the guinea pigs to run about the ground floor without going through the doorway and thus makes the cage too small to freely move about.
• DO NOT use an elevated feeding area like the one featured in this cage
  Many cages come with an elevated feeding area - a small ledge that clips onto the side of the cage that provides hiding space underneath and an area on top for the food dish. Guinea pigs are not climbers. They shouldn't have to climb to get to their food and a fall from the ledge can cause serious injury. Additionally, the area underneath does not have adequate ventilation. Remove this feature from the cage.