Care and Feeding of the Green Iguana

by the Winter Park Veterinary Clinic

1601 Lee Road

Winter Park Florida 32789

(407) 644-2676

last revised 3/96

Disclaimer:The Winter Park Veterinary Clinic has given me (Catherine Rigby) permission to reproduce this clinic handout on-line with the understanding that the clinic may have a newer version of this document with more up-to-date information that will render this on-line version no longer concurrent with the hardcopy information the clinic distributes.

Reptile information is continually being updated as more is learned, and the Winter Park Clinic makes it a practice to keep their handouts as up-to-date as possible.

The green (or common) iguana, Iguana iguana, is a tree-living and daylight-active lizard found in the subtropical regions from Northern Mexico to central south America. It is most often found in the vicinity of rivers and streams.

Iguanas have short, powerful limbs equipped with sharp claws needed for climbing and digging and have strong tails useful for protection (as a whip) and for swimming (which they do well.) a large flap of skin, the dewlap, hangs from the throat and help regulate body temperature. Iguanas also have a prominent crest of soft spins along the midline of the neck and back (males have longer spines than females). Adults can reach a length of 6 1/2 feet.

Male iguanas tend to be larger, have larger heads and have brighter overall coloration than females. The distinctive color of males is more pronounced during breeding season. Both sexes have a row of 12 to 13 pores on the underside of both thighs. These pores secrete a waxy substance used by iguanas to mark their territory and identify each other. As males mature, their femoral pores develop outward projections used during copulation to better grasp the female.

An iguana's skin is covered by tiny scales. Iguanas cannot change their coloring as chameleons do, but certain areas of their skin can become darker when exposed to sunlight. Young iguanas are pale green with black ringed tails. They mature to a lighter, more earthy color, usually with dark vertical bars on the body and tail.

In their natural environment, iguanas tend to be wary, hiding or fleeing at the first sign of danger. They use their acute vision, hearing and sense of smell for survival. Iguanas are clumsy but accomplished tree climbers. They bask by day in tree branches (often over water) from which they can drop and swim away when threatened. their powerful tails are used to propel them through the water using long, side to side strokes. Iguanas can drop from substantial heights to the ground and race quickly to cover. When cornered, they defend themselves with whip-like lashes of their tails and with claws and jaws.

Iguana mate in January or February. After a pregnancy of about 2 months, the females dig in moist sand or soil, usually near the base of a tree, and deposits 25 to 40 eggs. the hatchlings emerge in about 2 weeks. Sexual maturity is attained in about 3 years.

Although iguanas make good pets, they are high maintenance. Proper diet, caging and exposure to light are all important to good health. Providing all three can be time-consuming. Iguanas are not "casual" pets. Good education in their health requirements is the first step BEFORE purchase of the reptile. Teenagers and youngsters frequently purchase iguanas for the novelty without regard to the necessary care.

DIET AND SUPPLEMENTATION

In its natural environment, the iguanas is almost exclusively a plant-eater from the time it hatches ( a foliovore -- an animal that primarily eats leaves). We strongly recommend the following diet:

GENERAL INFO: Wash, finely chop and thoroughly mix all plant material. a food processor is recommended. This helps ensure a balanced diet by forcing the iguana all offered items, not just the favorite or tasty ones. Prepare enough for 4 to 7 days, store in the refrigerator, and serve at room temperature or slightly warmer.

INGREDIENTS: Each meal contains ingredients from all five of the following:

1) Calcium-rich vegetables (30 - 40 % of the diet, 2 or more items per feeding): turnip, romaine, mustard or beet greens, kale, collards, bok choy, Swiss chard, dandelions, parsley, escarole, spinach, alfalfa pellets

2) Other vegetables (30 - 40% of the diet, a variety weekly): frozen mixed vegetables, squash, zucchini, sweet potato, bell pepper, broccoli, peas, okra, grated carrot, sprouts

3) Grain/fiber (optional, up to 20% of the diet): whole grain bread and natural bran cereals

4) Fruits (no more than 15% of the diet ): fig, papaya, melon, apple, peach, plum, strawberry, tomato, banana with skin, grapes, kiwi

5) Vitamin/mineral supplements (Nekton-Rep is recommended) mixed with powdered calcium carbonate (cuttlebone shavings) or calcium gluconate. Mix one part vitamins to 2 parts mineral (calcium). (Tums can also be used as a calcium source.) Hatchlings and juveniles get one small pinch per feeding; adults get one full pinch per two pounds weight twice weekly; adult females get 1 full pinch per meal from December until egg laying.

(Supplementation is advised because vitamin/mineral deficiencies are common in captive iguanas. However calcium and fat soluble vitamins (A, D, E, K) can be over-supplemented. To avoid over supplementation, obtaining vitamins from a varied diet is the best choice with modest and control doses of vitamin/mineral additives. To date there are no documented studies on the specific dietary requirements of the green iguana.)

Hatchlings up to 14 inches in length: Feed twice daily or provide continuous availability. Plant mater needs to be finely chopped or shredded.

Juveniles up to 2 1/2 years old or 3 feet in length: Feed once daily. Plant matter fine to medium, chopped or shredded.

Adults over 2 1/2 years and 3 feet in length: Feed once daily or every other day. Plant matter coarsely chopped.

ANIMAL PROTEIN (MEAT) SOURCES ARE NOT NECESSARY. Some iguana books falsely claim iguanas eat small insects as hatchlings an change to plant eaters as they mature. they are vegetarians from birth even though they may accept unnatural food sources (such as crickets and small mice) while in captivity. there is no scientific documentation showing the need for animal protein sources. AVOID FEEDING CRICKETS, MEALWORMS OF ANY TYPE, SMALL MICE, PRIMATE DIETS, TROUT CHOW OR DOG AND CAT FOOD.

Canned, frozen or other commercial iguana diets are more convenient than preparing a fresh salad weekly, but these commercial diets may not be nutritionally balanced. Young, rapidly growing iguanas have different dietary needs than adult iguanas, just as puppies are different than adult dogs. Commercial iguana diets do not address this difference and are unproven to sustain iguanas as the only source of nutrition. The ingredients often are a mix of items not available to the wild iguana. Commercial diets may have a role in iguana nutrition, but more study is needed.

INTESTINAL INOCULATION

In the Wild, young iguanas obtain necessary intestinal bacteria by eating the feces of an adult iguana. The bacteria is needed to properly digest plant matter. hatchlings of not emerge from the egg with these bacteria, so iguanas reared in captivity never acquire them.

All newly purchased, domestically raised iguana can benefit by eating fresh feces from a parasite free adult iguana. One dose is often enough for the life of the iguana.

CAGING AND HYGIENE

Next to adequate nutrition, no other aspect of iguana husbandry is sanitation and hygiene. Many bacterial and fungal diseases develop from their daily exposure to fecal contamination and a damp, filthy environment. In the wild, iguanas have acres of land and water over which their half eaten food and feces can be scattered. This is obviously not the case with captive iguanas. Owners engage in a continual struggle to prevent bacterial build up caused by the accumulation of waste products and uneaten food.

The cage bottom or aquarium floor is best covered with butcher (brown) paper or indoor/outdoor carpeting. Do not use pea gravel, shredded corncob, wood shavings, sand, kitty litter or sawdust. None of these products promotes the necessary level or cleanliness and may be accidentally eaten by the iguana, causing intestinal impaction. Likewise, moss retains moisture can be the source for bacterial infection of the skin. Having several sections of carpeting is best. When one piece becomes soiled, it is removed and another piece is laid down. The first piece is then cleaned and disinfected and set aside to dry. Paper can also be used in sections for easier replacement.

A captive iguana's environment must be kept fastidiously clean and dry if serious problems are to be avoided. Any object soiled with feces or urine is best removed, cleaned and dried as soon as possible. Set up the iguana's enclosure with easy maintenance in mind. Human nature dictates that the longer takes to clean a cage, the less likely it will be to get done. There fore, make the enclosure functional rather than beautiful.

Reptiles are highly susceptible to poisoning form common cleaners. Avoid products such as Lysol, and Pinesol. Chlorine bleach, diluted at the rate of 2 ounces bleach to 1 gallon of water, is the recommended disinfectant. Be sure to clean the enclosure with soap and water before bleaching. Organic matter (feces, urates, food) will inhibit the action of the bleach. Rinse all surfaces with water and let dry before allowing contact with the iguanas.

VISUAL SECURITY

We recommend a hiding place where the captive iguana will be free from constant scrutiny. Use cardboard rolls from paper towels for small iguanas, and cardboard boxes for larger specimens. Better yet are carefully placed artificial plants (silk or plastic) that also provide basking areas above the floor of the enclosure. artificial plants will stand up to disinfectants and will not be chewed by the iguana.

FOCAL HEAT SOURCE AND SUNLIGHT

Iguanas require a warm environment to raise their body temperature and increase their metabolic rate and overall activity level. The optimal environmental temperature for iguana enclosures is between 85 deg F and 103 deg F. a thermometer placed in the enclosure is very helpful.

In the wild, iguana bask in sunlight to obtain both heat and necessary ultraviolet (UV) light for the proper absorption of dietary calcium. Unfortunately, captive iguanas do not receive sufficient sunlight, and suffer several health consequences even if one a proper diet. Captive iguanas require 2 hours of natural sunlight daily for optimum health. Window glass and plastic enclosures filter UV light. Setting your iguana near the window will provide heat, but the vital UV light will be insufficient for his needs.

Artificial light sources (such as Vitalite) can be used, but require much longer exposure times to be effective. Supply 10 to 12 hours of light and 12 to 14 hours of darkness daily. Increase the daylight hours in the spring and decrease in the fall and winter. Artificial UV sources need to be on for at least 8 hours daily. Even if you supply artificial UV sources, we recommend exposure to natural sunlight as often as possible. Provide some shade so the iguana can move out of the sun if it gets too warm.

Heat is best provided by a light source rather than a hot rock or similar device. Burns from hot rocks are common and can lead to serious skin/scale infections. Gentle heat can be provided by a heating pad placed BENEATH the enclosure or by commercially available heating elements in the enclosure floor. These elements often have a temperature control and/or timer, allowing careful control of available heat.

WATER

Water can be made available to captive iguanas in a variety of ways. a standing water source, such as a ceramic dish, can be used for bathing or drinking. Change the water once or twice daily. Misting the artificial plants in the enclosure and allowing the iguana to lap; the moisture is an alternative.

The bathtub is a wonderful recreational area for your iguana. Swimming is great exercise and the tub is a nearly escape-proof holding area for times when the iguana’s enclosure is being cleaned. Put enough water into the tub to allow 2/3 immersion of the iguana (he can touch bottom). The water temperature is best when warm to the touch. Iguanas can swim in a chlorinated pool for short periods of time with CLOSE SUPERVISION. Rinse the iguana completely after swimming.

CAGE MATE

Iguanas are quite territorial and not very sociable. A cage mate is not recommended. The addition of other iguanas in the same enclosure only invites aggression and fighting ( and additional trips to the veterinarian).

SHEDDING (ECDYSIS)

Iguana shed their skin in pieces. as one area sheds, other areas may not be ready to shed. Avoid peeling off dead layers of skin that may expose and damage new skin that isn’t yet ready. The skin on the tips of toes and tail-tip sometimes fails to shed at the same time as the rest of the foot or tail. Gently remove this skin after soaking the iguana in a tub of lukewarm water for 30 - 60 minutes. Use caution when doing this to avoid injury to the toes or tail.

DISEASES REQUIRING VETERINARY ATTENTION

Metabolic Bone Disease (Fibrous Osteodystrohpy)

The most common disease among captive iguana results from gross malnutrition. Most new iguana owners are often given improper nutritional advice from pet shops where the reptiles are purchased. Frequently, the owner feeds only lettuce and squash to the exclusion of other vegetables. (Lettuce is simply a water sponge devoid of nutrition.) The problem is aggravated by the lack of calcium and vitamin D3 from little or no exposure to sunlight and improper (or no) vitamin/mineral supplementation. Unfortunately, some of these iguanas appear well fed and chubby. Veterinary care is often not sought until they are in serious danger of dying.

Symptoms:

• listlessness
• swollen jaw
• soft/rubbery lower jaw and face
• difficulty eating
• markedly firm, swollen limbs (“Popeye legs”).
• Limbs and spine also fracture easily. (This is often the main reason veterinary care is sought.)

Paralysis of rear legs

Vitamin B1 deficiency results in paralysis of the rear legs and tail. Metabolic bone disease may also be at cause due to low dietary calcium. Treatment by injection of the necessary vitamins/minerals and a change to the proper diet is necessary.

Nose abrasions.

Repeated attempts to escape can result in scratches and abrasions to the nose and face. Iguanas tend to push and rub their noses along the sides of their enclosures as they pace, searching for a way out. Abrasion can result from either glass/plastic or wire enclosures. The constant irritation causes ulceration of the rostrum (nose and face) and serious (often permanent) deformities. Bacterial infection may also result.

Preventing this problem is difficult, but providing sufficient visual security helps to minimize pacing. Artificial plants that provide adequate basking places are also very helpful. IN some cases, a dark plastic film can be attached to the lower 4 inches of the enclosures walls (outside) to limit visibility.

Thermal injuries (burns)

Serious burns often result from contact with improper heat sources within the enclosure. Exposed light bulbs and hot rocks are the common causes. Hot rocks are notorious for causing burns when their internal heat control fails and the rocks temperature rises dramatically. Ultraviolet and incandescent lamps used for light and heat are best placed above the enclosure and out of reach of the iguana. Never place an incapacitated or ill iguana on a heat source such as a heating pad or rock.

Symptoms:

• blackened skin
• red skin
• peeling scales over moist ulcers.

Bacterial Infection

Blister disease results from constant exposure to a damp, filthy environment. Blisters form on the underside of the body that develop into serious skin lesions. (ulcers).

Dry gangrene of the tail or toes -- infections usually start on the tip of the tail and toes and progress toward the body. The tail and toes turn dark grey, then black, and may break off. The infection may occur on any foot, several feet, or only the tail. Improper sanitation is the cause.

Mouth rot -- is a bacterial infection often associated with malnutrition and a weakened condition. Swelling, inflammation and the accumulation of pus in the mouth, difficulty in eating and increased salivations are all signs of mouth rot. Force feeding the iguana is often necessary during the treatment.

Abscess -- result when bacteria settles in one or more places in the body and cause local swelling and the formation of pus. Reptile pus is not liquid but a thick, almost rubbery substance that resists draining. For this reason, abscesses are often removed surgically by opening the swelling and cleaning out the abscess material. More than one surgery may be necessary since some abscesses continue to fill until the infection is completely under control.

Iguanas are given antibiotics by injection to treat bacterial infections. For many owners, learning how to give these injections is difficult due to squeamishness or fear. There is little you can do to hurt your iguana when giving an injection.

Parasites.

Parasites are found externally (mites), within the gastrointestinal tract (worms, protozoa) and within the blood (malaria-type organisms). Parasites add to the stress of living in captivity and can seriously injure the captive iguana, sometimes causing death. Iguanas suffering malnutrition or chronic bacterial infections are most likely to die due to parasites. Fecal, Skin and blood examination will determine the type of parasite and dictate the appropriate drug to control the pests.

Viral Infections

Viral infections are probably responsible for some illness in captive iguanas, but little is known of these disease agents. Continued research will increase our knowledge in the future.

Organ Failure.

Organ failure accompanies advancing age and may be the consequence of gout or severe bacterial infection. Diagnostic blood tests help pinpoint the affected organ(s).

Symptoms:

• vary with organ
• weight loss
• listlessness
• loss of appetite
• bloating
• fluid accumulation in the abdomen
• death

Bladder Stones

Minerals in the urine may precipitate and form stones within the urinary bladder. The abdomen may become enlarged if the stone becomes very large. Female iguanas may have difficulty passing eggs or not be able to pass eggs at all if large bladder stones are present. Radiographs (X-rays) may be necessary to confirm the presence of stones.

Symptoms:

• listlessness
• blood in droppings.

(Symptoms are not always present.)

Egg-binding

Egg-binding can be a life-threatening condition that occurs when the female cannot expel one or more eggs from the reproductive tract. Malnutrition (especially mineral imbalances), mummification of eggs, large or malformed eggs, bladder stones and certain diseases can cause egg-binding. Physical examination and radiographs are helpful in diagnosis. Surgery is often necessary to resolve the problem. The iguana can be spayed at the same time (and is frequently necessary) so future problems are eliminated.

Broken tail

Fractures, dislocations, accidental amputation and crushing of the tail is possible in captive iguanas (especially those who are allowed to roam the house). Treatment depends on the nature and severity of the injury.

Broken toes.

Iguana toes are very vulnerable to injury, especially when housed in screen or wire enclosures. It is very easy for toes or toenails to be trapped within the wire mesh, resulting in fractures and torn nails. The injuries often occur when panicked iguanas are removed from their enclosure; when free roaming iguanas catch their nails in carpeting or furniture fabric; when iguanas struggle to escape their enclosures. Bleeding nails can be stopped with flour or cornstarch applied to the nail. Fracture and the lacerations (cuts) on the toes or feet require veterinary care.

A COMMENT REGARDING SHARP CLAWS

Iguanas do not always enjoy handling and can inflict painful scratches on the owner. The same powerful limbs and sharp nails used to climb trees can be used quite effectively to climb you. We recommend trimming the iguana’s nails as needed to reduce these scratches and prevent the claws from snagging in carpeting and furniture fabric, possibly breaking toes or pulling out the nails. Because nail can bleed easily when trimmed, this procedure is best done by one of our veterinary technicians or veterinarians. a high-speed grinding tool is often used to cut the nail and stop the bleeding at the same time.

VETERINARY EXAMINATION

A thorough initial examination is the cornerstone of good health program for iguanas. all newly acquired iguanas, regardless of age, can benefit from a complete physical given by one of our veterinarians. A stool examination will detect parasites and the physical examination may uncover diseases not obvious at first glance. Many diseases seeing iguanas are due to insidious processes such as malnutrition and poor sanitation. These problems can be detected and the situation corrected before the disease become life-threatening. A yearly examination allows monitoring of growth and health status as the iguana ages.