Green Iguana Care
About Green Iguanas
The green iguana is a large diurnal arboreal reptile found from Mexico into Brazil. Both sexes lead solitary lives except during the breeding season and are territorial. Until recently it was assumed younger animals were partially insectivorous to facilitate rapid growth, but now it is believed iguanas generally are herbivorous throughout their life, although they occasionally accept carrion and insects. Growing iguanas achieve faster growth rates by selecting diets higher in digestible protein and maintaining higher body temperatures which is believed to increase digestive efficiency. Studies in Panama found that iguanas ate leaves, fruit and flowers of select trees, vines and bushes in short frequent feeding bursts concentrated from late morning to early afternoon. Most plant species in the diet were abundant, but the lizards exerted effort to eat less common species and seasonally available foods. Although a wide variety of plant species were eaten, stomach contents typically consisted of one or two species, and researchers speculate that dietary diversity is accomplished over a period of days rather than each day.
Reproduction
Adult iguanas are easy to sex because the ventral femoral pores are much larger in males compared to females, and males have hemi-penal bulges at the ventral base of the tail. Males also grow much larger. In juveniles these differences are more subtle. Probing is an unreliable method of sexing except in large animals. Sexual maturity can be reached within two years, but breeding usually is not successful until the third year in captivity. Females in Panama lay clutches of 23 to 60 eggs (mean=40) from late January to mid-March during the dry season and hatchlings appear in 90 days at the start of the rainy season. Under artificial incubation at 27 to 35oC (80 to 95oF) eggs hatch in approximately 93 days. Larger females lay larger clutches.
Females need to excavate nest burrows before they will lay. It is tempting to speculate this is one reason females often become egg bound in captivity. Artificial nesting chambers have been constructed from six half-width solid cinder blocks (40 cm by 20 cm by 10 cm), and females avidly accepted these. These were constructed in a pit by placing one cinder block flat at the bottom, one at each side, one across the back, and two perpendicularly to the others to form a roof. The cavity inside the cinder blocks was packed with 7 cm of soil, and two 15 cm-diameter clay tubes 30 cm long were placed in line with the one open side. The whole structure then was buried including most of the inside of the tubes, with soil tapering away to the exposed entrance. With a little imagination, one could fabricate a similar, simpler structure in captivity. One author suggests using a large-diameter clay or PVC tube (one foot wide by three feet long) sealed off at one end. The tube then is half filled with damp sphagnum moss, and females often will lay eggs in it.
Growth and Size
In captivity, iguanas grow rapidly (30 to 60 cm/year), reaching adult size within two to three years, and can live 10 to 15 years if properly fed and cared for. Owners should invest in a larger aquarium initially or be prepared to purchase a large one later. A 20-gallon aquarium is adequate for juveniles, but within a few years most owners must build larger glass, plywood and screen cages. Wood should be sealed with nontoxic sealant such as polyurethane and allowed to dry and air out for several days. Allow as much vertical space as is practical to accommodate their arboreal lifestyle.
Housing/Cage
Iguanas live solitary lives in the wild except for breeding and should be housed individually in captivity. Unfortunately, this generally is impractical, and it is not uncommon for iguanas to be kept in groups. Iguanas which have been housed together for years will suddenly start fighting, and severe trauma can result. Males can kill other iguanas in their cage, particularly during breeding season. For multiple iguana households, several smaller cages are preferable to one large communal cage.
It is not advisable to allow iguanas to roam free in the house because of the numerous hazards they can encounter. Other pets, particularly cats, regard iguanas as prey that must be attacked without hesitation.
The bottom of the cage should be lined with newspaper (the cheapest and easiest to use), Astroturf (make sure it has no loose ends that can be eaten), wood chips (large enough that they cannot be eaten), alfalfa pellets, or sphagnum moss. Avoid sand, gravel, dirt, crushed corn cob, or kitty litter as substrates because they can cause numerous problems and are difficult to clean. If one uses Astroturf, buy a second piece so a clean dry one can replace the one that is being washed and dried. If using newspaper or Astroturf, cages should be cleaned weekly (or sooner if dirty). Alfalfa pellets, sphagnum moss, and wood chips should be changed every several months, but feces and moldy alfalfa pellets need to be scooped out weekly. Constantly moist or filthy environments are potential sources of infection. For most cleanings, hot water is enough to rinse out the cage; more thorough cleaning with a 5% bleach solution is only needed once or twice a year.
Hardwood driftwood branches for climbing and basking are appreciated. A water bowl big enough for the iguana to enter and soak also is needed and should be cleaned whenever dirty or at least twice a week. Iguanas need access to water at all times and not just once a week. In the native state, iguanas usually are found in close association with water.
Iguanas are very prone to retained shed skin on the toes and tail. In time these accumulate and gradually compromise circulation to the toe, which drops off or becomes infected. Owners should watch closely for stuck shed skin and remove them whenever present. One way to prevent this is to place a plastic shoebox or Tupperware container with an entrance cut into one side in the cage. The container is half filled with damp vermiculite or sphagnum moss and the lid replaced. This allows an area of high humidity in an otherwise dry cage. In drier parts of the country, keep the cage humid but not wet by spraying it several times per week or using a humidifier.
Iguanas spend much of their day in the tropics soaking up the sun and prefer it slightly warmer than most reptiles. Cage temperature should not drop below 75oF at night and gradually rise to between 85o and 95oF during the day with a localized hot spot or basking area of 95o to 100oF. Numerous studies of wild iguanas have shown that adult iguanas maintain body temperatures between 36o and 37oC (96.8o to 98.6oF) by basking in the sun. Iguanas are hind gut fermenters, and it probably is not coincidental that mammalian hind gut fermenters also have similar body temperatures. Assuring one's iguana a hot spot is important for proper digestion.
Suggestions for maintaining this temperature include the following. Keep in mind that each setup is different, so it is difficult to advise what will work well in each owner's home. The basking area can be provided by placing a 60- to 100-watt incandescent light bulb with reflector outside the cage or resting on the screen top so that it warms a branch or rock in the cage. A small infrared light also works well, but make sure it is at least 18 inches from the iguana. With either light, make sure the iguana cannot come into direct contact or too close to the light or serious thermal burns may result. Iguanas have been known to hang directly on light bulbs while their skin slowly burns! The best way to heat the rest of the cage is with a space heater, keeping the room between 75o and 90oF. Other less desirable heat sources include heat tape, heating pads, or hot rocks. Again make sure any heating sources hot enough to burn the iguana are not present inside the cage (anything too hot to rest a hand on or under for several minutes eventually will burn the reptile). Heating sources outside the cage are much safer.
In warmer parts of the country, sunlight is an excellent source of ultraviolet (UV) light and is recommended. Unfortunately glass and most plastics filter out UV light (unless specifically UV transmissible), so windows do not help as a source of UV light for indoor animals. Ultraviolet lights are recommended (see section on UV lights). The lights should be on for 12 to 14 hours per day year round and turned off at night. A timer helps keep them on a regular photoperiod.
Nutrition
Nutritional requirements for green iguanas are poorly understood and captive diets often are unbalanced. The following recommendations have been compiled from several sources. For young growing animals, 80% of their diet should be plant based and 20% protein based. Once the iguana reaches adult size (this should take two to three years), protein can be reduced gradually to 5% of the diet and plant material increased to decrease the load on the kidneys. Of the plant material, 80% to 90% should be vegetables and 10% to 20% fruits. Most iguanas relish fruits, but they are mineral poor and should be restricted. Think of fruit as a treat that can be given from time to time. Those foods listed in bold print have a positive calcium to phosphorus ratio. Vegetables will make up the bulk of the diet, and leafy greens with a dark green color will make up the majority of the vegetables. Dark leafy greens that are rich in calcium include collard, mustard, and turnip tops or greens, alfalfa or Timothy hay, alfalfa chow, Buffalo grass, broccoli rabe and dandelions (flowers, stems, and leaves) and should be the cornerstone of a healthy diet. Other dark leafy greens include bok choy, Swiss chard, clover, kale, beet greens, escarole, parsley, spinach, watercress, savoy, and kohlrabi. Other types of vegetables include alfalfa, radish or bean sprouts, asparagus, bell peppers, carrots, cucumbers, green beans, jicama, mushrooms, okra, peas and pea pods, prickly pear cactus pads (remove the spines), shredded squashes (such as green or yellow zucchini), sweet potatoes, soybeans, and uncooked thawed frozen mixed vegetables (corn, green beans, lima beans, peas, carrots). Spinach and beets have calcium binders in them, so they should be fed in moderation. Cabbage, broccoli, brussels sprouts, bok choy, cauliflower, kale, and other members of the cabbage family might cause thyroid problems if fed exclusively but are nutritious in moderation. Flowers such as roses, nasturtiums, carnations, and hibiscus are excellent. Mulberry leaves are good if available. Lettuces, including Romaine, have little nutritional value.
The other 10% to 20% of the plant portion can be various fruits. Figs are one of the few fruits rich in calcium. Apples, apricots, dates, grapes, kiwis, melons, peaches, papayas, pears, plums, prunes, raisins, strawberries, and raspberries are all fine in small amounts. Iguanas are fond of bananas; unfortunately they have very little calcium present.
The other 5% to 20% of the diet, depending on the size of the iguana, should consist of protein sources. "Protein sources" is a term of convenience in communicating with owners but is problematic because plants also are obviously good sources of protein. In this context, protein sources refers to canned, semimoist, or dry dog chow, Purina trout chow, monkey chow, or Hikari chichlid pelleted fish chow, pelleted bird chows, or whole gold fish, baby mice, or adult mice (depending on the iguana's size), drained whole sardines, soaked dry legumes (beans), tofu, pizza, hard-boiled eggs, insects, earthworms, and commercial reptile diets are acceptable in small amounts. All the dry chows need to be soaked first in water until soft. Feed a wide variety of these foods, not just a few. Dog food and monkey chow should be limited to less than 5% of the total diet because of high vitamin D content." Do not feed cat food because it is too high in protein, fat, and vitamin D for iguanas."
To make a salad, wash, chop, and mix two or more types of dark leafy greens, thawed frozen mixed vegetables, several types of fresh vegetables, and a fruit and protein source. Salads can be stored for a week in the refrigerator. For hatchlings, it is important to chop food into very small pieces (food processors work well) and mix it thoroughly to prevent them from eating only their favorite items. Each week slightly vary the diet by offering different food. Finicky eaters can be encouraged to eat more by heavily mixing in preferred foods at first and then gradually decreasing them over a few weeks. Persistence eventually pays off with novel items, but keep in mind iguanas also can have individual likes and dislikes.
The amount to feed is not an exact science, but in general feed enough that the reptile continues to gain weight and grow, but not so much that it becomes obese. If the iguana eats everything one offers and still seems hungry, then feed it more. Most young iguanas grow very rapidly, so one should notice appreciable growth on a monthly basis and weight gain on a weekly basis. Feed hatchlings daily until they are roughly six months old, then they can be fed like adults, three times per week or every other day.
Every feeding, sprinkle a light dusting of calcium carbonate, lactate, or gluconate or bone meal on the salad. Do not oversupplement with calcium! A fine barely perceptible dusting is all that is required. The supervisor of reptiles at the Dallas Zoo once told me he only supplements an amount of calcium that is expected to equal the amount of bone growth for that day. Obviously the correlation does not exist, but it is a very handy rule of thumb for owners. Ideally with a balanced diet, little calcium supplementation is necessary.
If the iguana eats the variety of chows in the protein portion, it is getting plenty of multivitamins. Multivitamin supplementation is required only if the iguana is not eating any of the chows, in which case a very light dusting of a good-quality reptile or bird multivitamin can be used two to four times per month. Multivitamin supplementation has been recommended with each meal but this seems excessive.
Variety is key to a healthy diet! Avoid feeding just dog food and a few vegetables and fruit. Until more is known, it is prudent not to rely on any one item for the majority of the diet (particularly items known to contain large amounts of vitamin D such as monkey chow biscuits). Recheck patients a month or two after restructuring their diet and go over diet again. Question owners as to what they are offering and what is being eaten (often there is a tremendous difference that many owners are reluctant to reveal). Captive reptile diets are just beginning to be understood so keep an open mind as recommendations are likely to change in the future.
Wild-Caught Iguanas
Wild-caught iguanas often are shy and should be minimally disturbed until they are eating well and seem less nervous. Have owners resist the temptation to try and tame them immediately, because this will further stress them and can be too much for an animal that is already maximally stressed. Allow them a few months to adjust to captivity. A hide box will give them a secure area in the cage for retreat. Particularly nervous individuals may need the cage covered so they do not bash their snouts whenever there is movement outside the cage or pace constantly along the glass barrier.
The majority of problems seen in green iguanas are the result of poor husbandry.
Wouldn’t you love somebody to love?
We’re supporters of
Pets Alive Westchester’s
mission to find homes for shelter dogs and cats, and proud sponsors of the
WFAS adoption of the week.
Check out AVMA's, Animal Tracks, a weekly podcast on animal health issues.
PetsMatter Bi-Monthly Newsletter
PetsMatter is your bi-monthly dose of pet health, behavior and lifestyle articles from veterinary professionals.
Westchester’s Best Vets
No surprise to our staff or our clients – we’ve got great people at Bond Animal Hospital! Our doctors were named among the county’s best veterinarians in the March issue of Westchester Magazine!
Check out their article here.
Breaking News:
Canine Influenza Update »
Animal Care Help:
Handouts on Pet Care and Training »
Educational Videos (e.g., dog training) »
When to see your vet:
Five reasons to see your veterinarian today
- Bleeding from anywhere
- Vomiting with a loss of appetite
- Acute pain – including eyes (squinting)
- Respiratory difficulty
- Sudden and extreme lethargy
Five reasons to see your veterinarian tomorrow
- Acute lameness
- Intense itching
- Decreased appetite
- Increased thirst or urination
- Persistent diarrhea
Five reasons to see your veterinarian soon
- Decrease in weight
- Change in activity levels
- Hair loss
- Bad breath
- Chronic lameness
Dental Health
PetFit Challenge
Pet owners understand that obesity is about more than appearance. Scientific evidence shows that obesity is a condition that can lead to serious disease. In conjunction with the AVMA and Hill’s our hospital is focused on raising awareness about the right way to achieve and maintain healthy weight:
- Proper nutrition
- Increased physical activity
- Regular veterinary visits
Click on the link above for tools to help you increase your pet’s activity, decrease their weight and start them living a happier and healthier life!
Bond Animal Hospital
250 Central Avenue
White Plains, New York 10606
general map |
view map»
Legal Notice | General Website Disclaimer
Website errors? Contact the Healthcommunities.com webmaster.
Please provide the website address in your message.
(Messages sent to Healthcommunities.com will not reach the practice.)
© 1998–2010 Healthcommunities.com, Inc. All rights reserved.
Medical Website Design by Healthcommunities.com