Ig u a n a
General Care of Green Iguanas
Susan Horton, DVM
Green iguanas are very popular pets. They are perhaps one of the most
misunderstood and poorly kept of all reptile pets. They can reach
considerable size. Recorded weights and lengths of adult male iguanas
have been as much as 20 pounds and 7 feet respectively. Certainly not
every iguana will become such a giant. But when considering an
iguana’s environmental needs, such size factors should be taken into account. They also
have specific temperature, humidity, lighting, and dietary needs
Environment
Cages
Keep in mind your cute little hatchling iguana will someday be much bigger. You may
start with a small 20-gallon aquarium now, but one day you will need a custom cage or
room dedicated to his reptilian needs. Surfaces of your chosen enclosure should be
smooth. Iguanas will rub their scales off their noses and hurt their feet if their enclosure
is made of wire. Wood may be used so long as it has been sealed with exterior
polyurethane varnish (such as marine varnish or similar). Allow the coating to cure for
several days and air it out well before inhabiting it. Moulded plastic and acrylic cages
work well until the iguana out grows them. Iguanas should never be kept loose in the
house. There are too many dangers this way, such as animal attacks, accidental injuries,
and chilling.
Your iguana will need branches to climb on. Chose branches of appropriate diameter and
strength to support his weight. Branches from outside can bring in pests. I suggest
either baking at 320 for 20 minutes or drying out over the outdoor gas grill for 30
minutes. Keep branch away from flames (for the obvious reasons). Choose hard wood
always. Pine and cedar will smoke heavily when baked! I usually use maple or oak.
Security is especially important for small iguanas. For these little guys I suggest covering
half the exterior of the cage with paper or towels to provide a safe refuge from perceived
predators (i.e. you, the dog, the cat, etc). Eventually you can remove this covering, once
the little guy has acclimated to his new surroundings (6 months or so). Silk plants may
look nice in the cage, but most iguanas will eventually try to eat them. They can be
placed outside the cage instead.
Bedding
I recommend newspaper or outdoor carpet. Newspaper should be changed often. If you
choose outdoor carpeting, have several pieces. This way you can be sanitizing one and
still have another to place in the cage. I do not recommend any particulate bedding,
(corncob, wood chips, wood shavings, etc.). It is swallowed easily by iguanas. Intestinal
blockage will lead to death if not addressed quickly. Particle bedding also hides a mess
well. The moisture from spilled water, faeces and urine build up in particulate bedding
and will promote bacterial infections in your iguana.
Temperature
An iguana can not digest properly or have a competent immune system without the ideal
heat. He is an ectotherm, which means he is the same temperature as his surroundings.
The preferred optimum temperature zone (POTZ) temperature for green iguanas is 85 to
95. The ideal night-time temperature is 80-85. A gradient within the enclosure is ideal.
This way the iguana can heat up and cool down as his body requires. Maintaining
temperature is difficult. Most enclosures require a heating mat applied outside the cage
with a thermostat to maintain night-time temperatures. For basking, a reflector with
appropriate wattage bulb will do. A branch should be provided under the bulb. For
iguana rooms, a space heater can be used. Build a protective barrier around it so the
iguana can’t get burned. Protect your iguana from burns by using a thermometer to
figure out the high and low temperature areas of your cage before you place him in it.
Never allow the iguana to touch the heat mat or bulb directly. Severe burns will occur.
Hot rocks are not appropriate. Your iguana is a basker, meaning he gets his heat form
basking in the sun. The hot rock will not heat the enclosure and will promote burns and
dehydration for your iguana. Do not place a glass enclosure in direct sunlight. It will
overheat and cook your lizard. Lights should go off at night. I use timers on my lights.
Humidity and water
Iguanas should be provided with a large water bowl. A large baking tray or cat litter box
is best. It must be cleaned daily. Iguanas generally use their water bowl as a toilet, thus
requiring frequent changes. Humidity is difficult to maintain in most iguana enclosures.
Daily misting will help. Soaking in the bathtub weekly is also a good idea. The tub should
have warm water to iguana shoulder level. Allow him to soak for about 20 minutes.
Never soak a weak or debilitated iguana without complete supervision. The enclosure
should never have condensation on the walls. This means you need more ventilation or
your cage is too wet. Skin infections often occur when the enclosure is excessively moist.
A hygrometer will read the ambient humidity. Ideally, iguanas need 65-75%.
Ultraviolet Radiation B
This is a one of the key elements in keeping a healthy iguana. Reptiles produce vitamin
D in their skin through exposure to UVB radiation. Vitamin D is important in calcium
metabolism. UVB wavelength measures 290-320 nm. When purchasing a UVB source,
check to make sure it provides this wavelength. There are several fluorescent bulbs to
choose from. Repti-sun fluorescent bulbs or mercury vapour bulbs produce adequate
UVB. The mercury vapour bulbs produce heat as well as UVB. They are very intense
and penetrate 2 to 3 feet into an enclosure and up to 12 feet with increased wattage.
The amount of UVB will be diminished if it paces through glass or plastic. I recommend
placing it on screen material. The iguana should be no more than 12 to 24 inches from
the fluorescent bulb. Exposure time should be 8 to 10 hours daily. Fluorescent bulbs
need to be replaced every 6 to 9 months because the UVB production stops about then.
I date my bulbs with a permanent marker to keep track of replacement times.
Nutrition
This is another key to keeping healthy iguanas. What you feed your iguana will
determine its lifespan. Proper nutrition from the start will ensure healthy bones and
kidneys. All food materials should be adequately washed, chopped and mixed. Young
iguanas need their food finely chopped. They may be fed twice daily. As they age,
feeding frequency decreases to once a day, then every other day for adults (3 feet and
longer). Ingredients for sub-adult meals should include items from these categories:
1.
Calcium rich vegetables: 40-50% of diet, 2 or more items per feeding-turnip
greens, mustard greens, beet greens, kale, collards, bok choy, Swiss chard, dandelions,
parsley, romaine, escarole, and spinach. Spinach must not be over used as it binds
iodine and calcium.
2.
Other vegetables: 30-40% of diet, a variety weekly. Frozen mixed vegetables,
squash, zucchini, sweet potato, bell pepper, broccoli, peas, beans, okra, carrot, and
pumpkin.
3.
Grain/fibre: up to 20% of diet. Boiled rice, boiled pasta, whole grain breads and
cereals.
4.
Fruit: contain mostly fructose and fibre. Dilutes more valuable nutrients in other
food items, so minimize its use. Figs, papaya, melon, apple, peaches, plums,
strawberries, tomatoes, banana (with skin), grapes, kiwi.
5.
Legumes: more important for young iguanas, up to 5% total diet. Boiled lentils,
navy beans, pinto beans, kidney beans.
Adult Iguanas are primarily fed the calcium rich veggies with small amounts from the
rest of the list periodically. Senior Iguanas are primarily calcium rich greens.
Vitamin supplementation is most important in to growing iguana. A multivitamin
supplement with calcium should be used daily. An example is Vetark Nurobal. *Older
iguanas (adults) require a multivitamin once to twice weekly.
Sanitation
Cage cleaning should include thorough scrubbing and disinfecting. For washing, use nontoxic soaps such as dish soap. Rinse well. For disinfection, dilute bleach (1:10),
chlorhexadine, or roccal (Upjohn, Kalamazoo). These must be rinsed very well. Allow
cage to air out well before iguana is returned. Daily removal of food is important.