Size
People purchase iguanas due to the small size, low price, and apparent low cost of feeding of juvenile iguanas. Though small as juveniles, iguanas can grow to six feet in length and weigh some 20 pounds.
Diet
Although they will consume a wide variety of foods if offered, green iguanas are naturally herbivorous and require a precise ratio of minerals (2 to 1 calcium to phosphous) in their diet.
There is some debate as to whether captive green iguanas should be fed animal protein. Zoologists, such as Adam Britton, believe that such a diet containing protein is unhealthy for the animal's digestive system resulting in severe long-term health damage and death. On the other side of the argument is that Green iguanas at the Miami Seaquarium in Key Biscayne, Florida, have been observed eating dead fish and individuals kept in captivity have been known to eat mice without any ill effects. De Vosjoli also writes that some animals have been known to survive and thrive on eating nothing but whole rodent block, or monkey chow, and one instance of Romaine lettuce with vitamin and calcium supplements.
Heat and light
Being tropical animals, Green iguanas will thrive only in temperatures of 75 to 95 degrees Fahrenheit (24 to 32 degrees Celsius) They require a source of Ultraviolet (UVA and UVB) lighting; without proper lighting their bodies cannot develop Vitamin D, and subsequently will develop metabolic bone disease which is fatal if not treated.
Legalities
In some locales, iguanas are considered exotic pets, and may be prohibited (New York City and Hawaii), or a special license or permit may be needed to own an iguana. Hawaii has strict regulations regarding the import and possession of Green iguanas, violators can spend three years in jail and fined up to $200,000.
Green iguanas are considered an invasive species in South Florida and along the gulf coast of Florida from Key West to Pinellas County. Over the years escaped and intentionally released iguanas from the pet trade survived and then thrived in their new habitat. They commonly hide in the attics of houses and on beaches and destroy gardens and landscaping. As most reptiles carry salmonella, this is also a concern and a reason legislation has been sought to regulate the trade in iguanas.
Socialization and habitat
Socialization of an iguana may take several years. Iguanas have individual personalities that require some adaptation on the part of the owner. At about five to ten years, an iguana may exhibit bonding behavior similar to that of mammalian pets. Such an iguana may have a complex "need of attachment" to include separation anxiety.
As pets
A pet iguana habituates to humans to such a degree that humans no longer cause a "fight" or "flight" reaction. Iguanas achieve this after they have acclimated to their new habitat and brief yet constant interaction with their owner.
Healthy pet iguanas are very observant, confident, and curious. Iguanas can be "potty-trained" to go outside (when it is warm), go in a specific location (as on newspaper) or in a tub of warm water (and even on the toilet).
Most veterinarians do not have the training to treat an iguana.
