Care of the Green Iguana

Congratulations on welcoming an Iguana to your family. We here at Four Seasons Animal Hospital want to help you with your new friend, starting with the basics…

Unlike domestic pets that have lived with human beings for multiple generations, pet reptiles, even those that are captive bred, are still essentially wild animals. Our goal for keeping iguanas in captivity should be to copy their natural environment and diet as closely as possible. Iguanas in the Wild The Green (or Common) iguana (Iguana iguana) is a tree-dwelling, daylight active reptile. It is a rainforest dweller found in the tropical and subtropical regions of central and South America and parts of Mexico. The iguana is a solitary creature. Soon after hatching, the young go off to live a solitary life. They come together only during the breeding season. The iguana is a strict vegetarian, feeding primarily on vines, stems, leaves, and flowers. The iguana also has an acute sense of sight, smell, and hearing. It tends to be a wary creature and will hide or flee at the first sign of danger. During the day it basks on tree branches which often hang over water. When threatened or frightened it will drop into the water or the ground below. If properly cared for, iguanas can live for up to 12 to 15 years and reach six feet in length.

Your Iguana’s Environment

Iguanas are asocial, territorial animals and should be housed singularly. Young iguanas may seem to coexist well at first, but problems soon arise. The larger, more aggressive iguana will physically intimidate its cagemates and monopolize food and heat sources. Consider elective castration and feeding high levels of plant phytoestrogens to reduce aggression in males. Variety is the key to good nutrition, foods offered should include:

  • Vegetable matter, offered as a chopped salad, should make up approximately 50-55% of the adult dragon diet.
  • Dark leafy greens (such as collard greens, kale, romaine, dandelion, turnip greens, mustard greens, beet greens, bok choy, Swiss chard, spinach, chicory, escarole). Other chopped or grated vegetables may comprise up to 20% of the diet (squash, zucchini, sweet potato, broccoli, peas, carrot, beans, okra, bean sprouts, tofu).
  • Animal protein should make up approximately 25% of the adult dragon diet. Appropriately sized crickets (body length no greater than the width of the dragon’s head), earthworms, grasshoppers, superworms (Zophobas), wax worms, locusts, and Pinky mice.
  • Avoid lightning bugs as they can be toxic.
  • Fruit should make up no more than 5% of the diet and should include nutrient dense items such as papaya, melon, and banana.
  • Treats may consist of non-toxic flower blossoms (i.e. hibiscus)

Suggested feeding schedules:

1-4 months old: Feed twice daily (crickets, veggies, occasional mealworm)

4 months to adult: Feed once daily (crickets, mealworms, pinky mice, salad every other day)

Adults: Feed every 1-2 days (crickets, vegetables); pinky or fuzzy mouse once weekly

  • Iguanas require vitamin/mineral supplementation.
  • Lightly dust all food items with a calcium carbonate supplement (without phosphorus or vitamin D). Prey should be dusted daily for baby iguanas . The frequency of dusting should decrease as your iguana ages so that by adulthood prey are dusted once weekly.
  • Any easy and thorough way to dust food items is to place both food and supplement in a plastic bag and shake vigorously.
  • When feeding live insects, be sure to offer “gut loaded” insects.
  • “Gut loaded” insect prey are fed high calcium diets for several days before being fed out. This may include fresh greens or commercial cricket diets.  A reptile multi-vitamin may be offered approximately once monthly.
  • Although iguanas thrive in low humidity, drinking water should always be provided in a shallow bowl or saucer. Iguanas will often soak in their water bowl and may defecate in their water. Drinking and soaking bowls should be cleaned at least daily.



A 10-gallon glass aquarium may suffice for young dragons, however juveniles will rapidly outgrow such an enclosure. Adults require very large arboreal enclosures (i.e. 6 x 3 x 6 ft or 2 x 1 x 2 m) so custom built cages are often needed. Screening is best for adequate air circulation although more effort will be needed to keep humidity levels high. Iguanas require hiding areas (rock cave, plant pot, cardboard box, etc.) as well as thick branches upon which to climb and bask. Branches must be sturdy enough to support heavy-bodied adults. The cage substrate must be easily cleaned and non-toxic. Newspaper or butcher paper are appropriate substrates. Astroturf is fine as long as it is kept clean and dry. Avoid sand, gravel or corn cob bedding because they may cause gastrointestinal blockage if ingested.


Proper temperature is very important. The green iguana has a preferred optimal temperature zone of 80-88°F (27-31°C). The basking spot should reach 92-95°F (33-35°C). The basking area should consist of an overhead heat lamp which simulates the sun and a branch that slopes upward so that the animal can select its desired temperature. Take care that the bulb cannot be contacted or your dragon may burn itself. Floor heat may be provided by a number of methods including under-tank floor mats. Hot rocks are not recommended since serious burns may arise secondary to short circuits. Place thermometers and hygrometers (to measure humidity) at the “cold and hot” ends of the cage at levels consistent with where your dragon spends most of its time.


Ultraviolet light is needed for normal absorption of dietary calcium. Consider exposing your pet to direct sunlight when outside temperatures are greater than 75-80°F. Keep your iguana in a wire or screened enclosure, be sure to provide a shaded area, and beware of the danger of overheating in the sun. A synthetic ultraviolet light source should also be provided for your bearded dragon. Be sure to choose a bulb specifically designed for reptile use that emits light in the UVB range of 290-320 nm. Ultraviolet rays are filtered by glass and plastic. Natural or artificial light must not pass through glass or plastic. The UVB spectrum generally degrades in about 6 months, therefore bulbs should be replaced every 6 months.

Common Diseases

Coccidiosis is a parasitic infection of the small intestine which may lead to diarrhea, lethargy, inappetance, and dehydration in the young dragon. Metabolic bone disease, a deficiency of calcium, ultraviolet light, and or vitamin D3, can lead to numerous problems including poor bone quality and fractures. Female iguanas often produce eggs, even without the presence of a male. Although a gravid female normally eats very little if at all, signs of egg binding may include lethargy, depression, and straining.


Never grasp iguanas by the tail. Green iguanas utilize tail autonomy, a defense mechanism that utilizes tail loss. A vertical fracture plane of fibroconnective tissue and cartilage runs through the body and part of the neural arch of each caudal vertebrae. The tail can fall off when grasped, sometimes when very little pressure is applied. The tail will regrow as a cartilaginous rod. Iguanas can also go on the “offensive”. They can bite and twist, utilize their sharp claws to scratch the handler, and larger specimens use their tails as a whip and will direct tail lashes at human eyes.

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