Health Topics


(By P. Alderson DVM)

For a healthy captive iguana, we need to look at their wild relatives. In the morning, wild iguanas will bask in the morning sunlight for 3 - 4 hours to warm themselves. After they are sufficiently warm they will forage for food. The wild iguana eats a variety of leaves, flowers and fruit of various plants. They are vegetarian. During the day wild iguanas are rather immobile, resting and digesting their dinner. They will bask in the sun later in the afternoon for 2 or 3 more hours, then retire to their trees early in the evening until sunrise. They like to sleep on branches over-hanging water, as they feel secure. They escape their predators by dropping in the water and swimming away. Knowing the habits of wild iguanas will help us keep and maintain the health of our captive iguanas, and gives insight into diet, lighting, humidity, housing, temperature and behaviour.


Iguanas grow rapidly. You must be prepared for the space needed to keep iguanas. Small housing space can cause stress, illness, and stunted growth. They reach adult size in 2 - 3 years, and grow 30 - 60 cm per year. Purchase a 20 gallon aquarium for juveniles, or be prepared to purchase this size in the very near future. A juvenile is younger than 2.5 years. Later, as they get larger, you may want to build a plywood and plexiglass enclosure that will allow them a life "in the trees". They like to sleep higher up in the trees and above a pan of water. It provides security and humidity. The pan of water should be large enough for the iguana to enter and soak in. Lining your enclosure with newspaper is best for cleaning. Cleaning should be done daily, as uneaten food will rot.

Iguanas are solitary by nature, unless breeding. They are best housed individually. Males will fight if housed with other males or immature females.

Iguanas can be allowed access to the rest of the house if supervised. But be aware of the dangers around your house.


Iguanas are tropical animals, and thus need higher temperatures. They prefer a higher temperature during the day (85 - 90 degrees F) and a lower temperature at night (75 - 78 degrees F). The environmental temperature should never drop below 70 degrees F. A localized hot spot can be provided, but they must be able to escape from this high temperature should it become too hot. This hot spot can be provided with a hot rock, or the preferred overhead basking lamp. All temperature changes should be gradual.

Ultraviolet Light

Iguanas must have UV light. Sunshine has adequate UV light, but NOT through a window. Windows filter out UV light. Indoor iguanas must be provided with fluorescent UV lights for 12 hours a day. Combining different UV sources is ideal (eg. black lights and full spectrum lights), but expensive.

However, it may be worth the investment. They need UV light to make Vitamin D. Without Vitamin D, they cannot use their body calcium and will develop Metabolic Bone Disease.


Iguanas must be handled regularly or they may become aggressive. Handle them daily as a juvenile. Train them to trim their nails. Never drop an iguana from any height. Never grab them by the end of the tail or the tail may break off. Iguanas will bite and scratch if frightened or not handled frequently.

If you just purchased an iguana, allow it sufficient time to adjust at home. You may want to leave it in a quiet area for a few days to get use to its new home. A hiding place, such as a box, will help it feel more secure.


IGUANAS ARE VEGETARIANS. DO NOT FEED THEM DOG OR CAT FOOD! Dog and cat food is too high in protein and will lead to kidney failure and death. Feed them a balance diet of vegetables as described below. If you prefer to feed a commercial iguana diet, supplement with fresh vegetables to boost vitamins and minerals lost through processing.

95% VEGETABLES: The diet should primarily consist of fresh vegetables, especially calcium rich vegetables. The following is a list of adequate vegetables. Remember to wash all food, and chop into bite size pieces. Juveniles will need the food chopped finer than the adults.

Calcium rich vegetables: dark leafy greens; such as collard, mustard greens, turnip tops, alfalfa, broccoli leaves (not the florets), bok-choy, swiss chard, beet greens, escarole, parsley, spinach, watercress. Flowers; such as roses, nasturtiums, carnations, dandelions and hibiscus.

Other acceptable vegetables include: clover, bean sprouts, asparagus, bell peppers, brussell sprouts, carrots, cauliflower, cucumbers, green beans, okra, peas, frozen mixed vegetables.

Feed spinach, beets, swiss chard and cabbage in moderation or thyroid problems may develop.

Iguanas love romaine lettuce, but romaine has little nutritional value and should only be a small part of the diet.

5% FRUITS: Iguanas love fruit, and will pick through the vegetables to eat the fruit. It should only be a small part of the diet. Acceptable fruit includes: figs, apples, apricots, dates, grapes, kiwi, melons, mango, peaches, papayas, pears, plums, prunes, raisins, strawberries, tomatoes, bananas and raspberries.

A very fine dusting of calcium powder should be added to daily feeding. Use a calcium supplement without vitamin D and phosphorus, as these are easily overdosed. An iguana multivitamin can be give once a month. DO NOT OVER SUPPLEMENT VITAMINS.

Veterinary Care

Iguanas need yearly check-ups to detect early problems and to fine-tune the environment. Different life stages require different care, and these need to be addressed for a long happy and healthy life. They can live 15 - 20 years if cared for properly.

Find a veterinarian who handles iguanas on a regular basis and is up to date on reptile medicine.

Your iguana is an investment and a pet. Take good care of it.

Please note: 60 to 80% of reptiles carry Salmonella. Practice good hygiene in order to prevent yourself from becoming ill. Young children (less than 5 years), elderly, and immunosuppressed people should not handle reptiles.