What type of cage does my iguana require?
You can start a smaller, juvenile iguana in a 10 or 20-gallon aquarium. The average adult iguana is 3-5 feet (1-1.5 m) long; however, adult male iguanas can weigh 15-20 lbs (7-9 kg), and larger ones can grow up to 6 feet (1.8 m) long when fed and housed appropriately. As an iguana grows, he or she must be moved to a larger enclosure, with accommodation for both horizontal and vertical movement.
"Glass or Plexiglas® enclosures with good ventilation are ideal."
Iguanas should be provided with a horizontal area for walking around, exploring, eating, drinking, and defecating, and a vertical area, such as a branch, on which climb and bask in the light and heat. You may choose to purchase or build a cage for your pet. If you choose to build your own enclosure, your veterinarian or pet store can likely provide you with details about how to set up the proper habitat for an adult iguana. Glass or Plexiglas® enclosures with good ventilation are ideal. The cage bottom should be easy to disinfect and keep clean and the cage should have a screened top to prevent the iguana from escaping, while still allowing some ventilation. A source of heat and ultraviolet (UV) light must be provided for iguanas to thrive. A visual barrier, such as a strip of dark colored duct tape, placed around the lower perimeter of a glass or Plexiglas® enclosure at the pet’s eye level, will help prevent the iguana from rubbing or striking its nose on the glass and causing sores, as it explores its environment.
Does my iguana need bedding in his cage?
Substrate, or bedding material, should be non-toxic and easy to clean and disinfect. Newspaper, butcher paper, commercially available recycled paper pellets, or artificial grass made for reptiles (commonly called “reptile carpet”) may be used as substrate. Avoid sand, gravel, wood shavings, corn cob material, walnut shells, and cat litter, as these are not only difficult to clean but also indigestible and can lead to gastrointestinal tract obstructions if eaten. Cedar wood shavings should never be used as reptile bedding, as the aromatic oils on the cedar are toxic to reptiles!
"Cedar wood shavings should never be used as reptile bedding, as the aromatic oils on the cedar are toxic to reptiles."
If you use reptile carpet, be sure you have an extra piece so that one can be placed on the cage bottom and the other can be kept as a spare that is ready to use when the first one is soiled (typically at least once a week). Clean the soiled turf with soap, water, and diluted bleach (1part bleach to 10 parts water) to disinfect. After washing, be sure to thoroughly rinse the carpet, and hang it to dry until it is needed at the next cage cleaning.
What else do I need in the cage?
Iguanas are arboreal, meaning they like to climb trees in the wild. Therefore, pet iguanas enjoy having access to tree branches in their cages. Branches that are clean and pest-free can be purchased commercially at pet stores. Natural branches from trees outside may contain fungus, bacteria, or parasites and therefore must be cleaned, disinfected with bleach, and baked in an oven to kill infectious organisms. With any branch, make sure it will support the animal and that it will not fall onto the lizard and injure it. Ideally, the branch should slope from the bottom of the enclosure to the top and should be near a source of UV light and heat, so the iguana can sit on the branch and bask. Large rocks in the cage also allow for basking. Iguanas also typically love a place to hide. Artificial plants or live, non-toxic plants also can be arranged to provide a hiding place, as can clay pots, cardboard boxes, large pieces of bark, split hollow logs, and other containers.
Reptiles are ectotherms, meaning that they depend on external sources to heat their bodies. Their body temperature adjusts in response to their external environment. They should have a range of temperatures within their cages to allow them to regulate their internal body temperatures. Iguanas slow down in cooler temperatures and tend to be more active when it is warmer. All reptiles require a heat source, such as a ceramic heat-emitting bulb, in their tanks to provide warmth. Alternatively, a heating pad may be placed under the enclosure to provide heat. Hot rocks or sizzle rocks that are meant to provide heat to a reptile when they sit on them can actually burn a pet and should never be used.
"Hot rocks or sizzle rocks that are meant to provide heat to a reptile when they sit on them can actually burn a pet and should never be used."
Ideally, the cage should be set up so that a heat gradient is established, with the tank warm on one end and cooler on the other. In this way, the iguana can move around its environment and warm or cool itself, as needed. It is easier to establish a heat gradient with a heat bulb set up over the tank at one end than with a heating pad placed under the tank that will only heat the tank where the pad is on contact with it. The cage temperature should be monitored closely, either with a point-and-shoot temperature gun or with two thermometers, one placed in the cool zone and the other in the warm zone. The cooler end of the cage should be approximately 70-75°F (21-24°C), while the warmer (basking) end should be 90-100°F (32-38°C). Heat bulbs should be placed outside and above one end of the cage, which should be covered by a screen top to prevent the iguana from escaping or burning itself on the bulb. At night, the UV and heat lamps may be turned off, as long as the enclosure’s temperature does not fall below 65-70°F (18-24°C). If the cage temperature falls below this level, especially in wintertime in cold climates, additional heat for the enclosure may be necessary.
What about ultraviolet (UV) light?
A wild reptile may spend many hours a day basking in the sun absorbing UV light. UV light is essential to enabling their skin to manufacture the vitamin D3 that the iguana needs for proper calcium absorption from their food. Failure to provide UV light can prevent an iguana from absorbing adequate calcium and can predispose an iguana to nutritional metabolic bone disease. This common, completely preventable condition of pet reptiles is fatal if left untreated. The UV bulb should emit light in the UV-B range (290-320 nanometers). Most bulbs sold for use in reptile housing provide both UVA and UVB; however, UVA does not contribute to the formation of vitamin D3. There are many excellent, commercially available UV lights made for reptiles. The UV output of these lights decreases with time, so they should be replaced every six months or as directed by the manufacturer. For UV light to be effective, it must reach the pet directly, without being filtered out by glass or plastic between the pet and the bulb. In order for the pet to receive maximum benefit, the bulb should be approximately a foot away from the animal and be on for 10-12 hours per day, mimicking a normal daylight cycle.
"For UV light to be effective, it must reach the pet directly, without being filtered out by glass or plastic between the pet and the bulb."
Regular exposure to direct sunlight outside, such as on a porch or an untreated lawn, is ideal for an iguana when it is warm enough outside and when the pet can be supervised to keep it safe from injury or attack from wild animals. When taken outside, an iguana must also be provided with a shaded area to move out of direct sunlight if it gets too hot.
Consult a veterinarian familiar with reptiles if you have any questions or concerns regarding proper lighting or other housing issues for your iguana.