FAQ: Iguana iguana

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FAQ: Iguana iguana

Post by Jennifer E. Swoffor » Tue, 06 Dec 1994 14:57:20



Here it is - the sort of preliminary text version of my iguana booklet
- in two parts.  First of all, none of the tables referenced
throughout this FAQ are to be found anywhere within this FAQ.  The
Ca:P ratio FAQ can be found here on RPH (posted a couple days ago) as
can the Toxic Plants FAQ.  There is no Nutritional Values FAQ as of
yet.  It will take me literally hours and hours to format that thing
so it's readable to all you out there in net-land, and right now I
don't have the time, so for now, let's wing it.  

Also, pay no attention to the stuff in the Preface about mailing and
copying costs - naturally, there are none for this electronic version.

Feel free to distribute this to anyone you would like.  At this point,
if you do, please also print out the toxic plants and Ca:P ratios FAQs
and include them, so this thing at least seems slightly polished.  :)
I shall be adding more info within the next few weeks, (before the
price of stamps goes up) so the next time this is posted, it may be
slightly longer.  (Yikes!)

Enjoy!

THE COMPLETE GUIDE TO KEEPING GREEN IGUANAS IN CAPTIVITY
by Jennifer Swofford

PREFACE

The intention of this booklet is to answer any questions an iguana
owner may have regarding the proper care of his or her lizard.  In the
few years that I have owned iguanas, studied iguana care, and
communicated with many other owners of iguanas around North America, I
think that I have acquired a firm grasp of what iguana owners want to
know regarding their pets.  This booklet has been arranged very
categorically, complete with a detailed table of contents, so that the
iguana owner may quickly find exactly what he or she is looking for.
I have found that, unfortunately, many iguana owners do not wish to
take the time to read entire books dedicated to iguana care, not even
the somewhat infamous Phillipe DeVosjoli's relatively short Green
Iguana Manual.  (See Source Materials section.)  In addition, many do
not wish to spend the money on such books because they think that they
have learned all there is to know about iguanas from the pet store
employee who sold them their iguanas.  Unfortunately, the information
one obtains from pet store employees frequently has the potential to
do more harm than good.  I hope that copies of this free booklet will
reach some of those out there who need help with their iguanas, and
perhaps it will even reach some pet shops that are still misinforming
their customers that spinach and kale should be staple items of their
iguanas' diets.  (Did that come as a shock to you?  Read on!)

I have arranged this booklet into three main parts.  The first part,
Green Iguana Nutrition, will of course answer any questions you may
have regarding nutrition.  Malnutrition is a common ailment among
green iguanas in captivity, an ailment that often leads to death.  In
the wild, iguanas must be sure to mask their sicknesses if they have
any, or else they will likely be eaten by opportunistic predators.  In
captivity, too, iguanas remain loyal to their natural instincts and
hide their sicknesses as long as they can.  Because of this, the
iguana owner frequently does not realize that their pet is ill until
it is too late.  The best cure for any iguana illness is prevention.
By following the rules outlined in the nutrition section, you will be
taking the first step toward providing your iguana with a happy,
healthy life.

The second part, Housing Considerations, is somewhat of a supplement
to the nutrition section.  Green Iguana Nutrition deals with what to
feed your iguana, which is one of the underlying factors in your
iguana's health.  But there are a few other factors that must be
considered if you want to keep your iguana truly happy and healthy.
Heat and sunlight, for instance, are absolutely essential for green
iguanas.  In addition, cleanliness, humidity, and the habitat that you
create for your iguana will play important roles in your iguana's
lifetime.  The information given in the housing section is just as
important as that in the nutrition section if you expect to own a
healthy lizard.

The third part is entitled Iguana Behavior and Maintenance and is
included simply to address any issues that do not fit in with
nutrition or housing.  It will address important issues such as how
often iguanas usually defacate, and what those head-bobbing actions
are for.  It will also address nail-t*** and bathing.  Feeding and
housing are probably the most important things you will need to know
to keep your iguana healthy, as almost all iguana "diseases" are
caused by management problems, as opposed to viruses that they can
just "catch" from other sources beyond your control.  But from
experience, I know that iguana owners want to know much more than how
to house and when to feed their lizards.  Hopefully this section will
answer any of the many miscellaneous questions you probably have.

The fourth part, Troubleshooting, will inform you of common problems
iguanas in captivity face, such as parasites and constipation, what
signs to look for when pinpointing the ailment, and in some cases, how
to cure the problem.  I am neither a veterinarian nor a herpetologist
(yet), but I am very familiar with the illnesses that iguanas commonly
face in captivity.  I cannot prescribe medicine for your pet but I can
help you decide when medicine might be necessary.  Above all, I ask
you to inspect your pet daily, from its head to its tail, and check
for changes or abnormailities that may be indicative of illness.  With
preventitive care and quick diagnoses, we can help our iguanas live
long, happy lives.

Other sections of this booklet include the Tables section, which
contains all of the tables referred to throughout the body of this
booklet.  The section entitled Source Materials aims to give credit
where credit is due.  This booklet could not have been written if I
were not able to study the materials that I did.  In addition, this
section provides a good reading list for the beginning
herpetoculturist.  (One who is interested in the captive care and
propagation of reptiles and amphibians.)

One final note.  This booklet was not written with either the new or
old iguana owner in mind, but with all iguana owners in mind.  Some of
the information in this booklet will be old news to many people who
have kept iguanas for a while, but I hope that they will read the
booklet anyway because what we know about iguanas changes rapidly.
New iguana owners may find some of the information in this booklet
invaluable.  In addition, even experienced iguana owners frequently
find their iguanas ill after keeping them for a number of years, and
the cause is often due to chronic malnutrition.  Sometimes what seems
to be a good diet does no harm for a number of months or even years,
but eventually catches up, leaving the owner dumbfounded as to the
cause.  The information regarding nutrition in this booklet is, as far
as I know, accurate and should help any iguana avoid problems caused
by chronic malnutrition.  

I hope you find this booklet to be useful, and I encourage comments
and questions.  If you feel I left out any important information, or I
spent too much or too little time on any particular topic, I would
love to hear your opinions.  I regret that I was unable to go in depth
into every single aspect of iguana care, and that I did leave out a
few interesting topics.  (Such as selection and taming: select healthy
looking iguanas that are alert and active, and if you have a wild one
on your hands, perseverence is the only cure!  Work with it daily.)
As time and funds allow, I will certainly add information into this
booklet, and also update information.  If you are interested in
obtaining updated information in the future, you can send me an SASE
and I will send you an addendum.

I encourage you to make copies of this booklet and distribute them to
anyone you know who might be interested.  I simply ask that you do not
change any information without my consent.  This booklet is free -
please do not sell copies except perhaps to cover your copying and/or
mailing costs.  I am very dedicated to educating iguana owners, and I
know that my charging even a small fee would result in decreased
circulation of this booklet.  But for the generous at heart,
contributions are welcome.  My costs are given on the inside cover of
this booklet.  Hundreds of copies will have been distributed by the
time you read this, and although I do not regret a single one, my bank
account does suffer!  All correspondence can be directed to the
address on the inside cover.  Thank you for your time, and happy
"igging"!

GREEN IGUANA NUTRITION

What to Feed: The Basics

Iguanas are folivores, which means that in their natural habitat they
dine almost exclusively on leaves.  Unfortunately, the leaves that
iguanas eat in the wild are not available to those of us who do not
live in Central or South America.  Therefore, we must offer our
iguanas a great selection of vegetables that are available to us in
order to insure that they obtain all of the nutrients essential to
their survival.  Offering only a few different varieties simply will
not meet your iguana's nutritional requirements.

Any old variety of vegetables, however, might not sustain your iguana
for very long.  Often times, foods of questionable nutritional value
are chosen and pet iguanas wind up with illnesses stemming from
malnutrition, usually from calcium deficiency.  Therefore, we have
some general guidelines to follow when picking out our iguanas'
lunches at the grocery store.  Again, these are very general
guidelines, and the next section, The Specifics, must be considered as
well when building your iguana's diet.

It is the opinion of a growing number of herpetologists that the diets
of both the juvenile iguana and the *** iguana should be the same,
except perhaps in the area of vitamin and mineral supplementation.
(See Vitamin and Calcium Supplementation section.)  The basic diet
should be comprised of the following portions of fruits and
vegetables:

35% should consist of calcium rich vegetables
                                                                                                                                                 15% or less should consist of nutritious fruits                                                                                                   20% may consist of breads and grains, but this remains an optional portion of the diet                                      
30% should consist of other nutritious vegetables

In the Tables section of this booklet, you will find Table 1:
Nutritional Content of Many Fruits and Vegetables, and Table 2:
Calcium to Phosphorus Ratios.  (See Calcium and Phosphorus section.)
Both will be helpful when choosing foods to fill the above categories.
Although you may not understand the significance of many of the
vitamins and minerals listed, (a few will be talked about later in
this section) you will at least be able to tell which foods are high
in calcium, and alternately, which seem to be deficient in most
vitamins and minerals listed, such as iceberg lettuce.  Also compare
arrowhead to other vegetables - you should be able to tell that
arrowhead does not stack up to most other food items listed.  Foods
largely deficient in nutrients should be avoided.  

What to Feed:  The Specifics

Keeping those basic guidelines in mind, there is some more very
important information that you need to know.  As you are probably
aware, there are some foods that can cause problems in humans when
eaten in excess.  Not surprisingly, the same is true with iguanas.
Humans are generally in charge of their own diets, and we tend to
intake a wide variety of foods simply due to the fact that many
different things are pleasing to our taste buds.  Most people eat
fruits and vegetables as well as meats, grains, and dairy products.
Eating so many kinds of foods helps to insure that all of the
nutritional requirements are met.  In addition, many of the foods that
we eat often, such as bread and milk, are usually fortified with
vitamins.  We may conclude that most of us receive all of the vitamins
and minerals necessary to sustain life through the foods we eat.
(There are certainly exceptions.)  Iguanas, however, are strict
vegetarians.  Some human vegetarians experience health problems
because they do not eat enough different kinds of vegetables
regularly.  Vitamin B12, for instance, is completely absent in most
vegetables but is present in most meats.  If a strict human vegetarian
is to obtain this vitamin, he or she must take it in the form of a
vitamin supplement.  Iguanas, too, can be deprived of essential
nutrients if they are limited to some particular group of
low-nutrition vegetables that their owner has unwittingly chosen.
Fortunately, much is known about the nutritional contents of fruits
and vegetables, and about some nutritional requirements of iguanas,
and you can use this information to sculpt a suitable diet for your
iguana.  

To help you choose, listed below is some important information about
several groups of vegetables, some essential nutrients, and some
nutritional requirements of iguanas.  They should all be considered
with equal importance and not ignored.  Nutritional deficiencies are
common in iguanas because many iguana owners are unaware of the
nutritional content of the foods that they are offering their pets.
Sometimes, even a varied diet can be a poor one if the wrong
vegetables are chosen.

Calcium and Phosphorus

The food that you give your iguana, on average, should contain about
twice as much calcium as phosphorus.  A generally acceptable range of
calcium to phosphorus ratios is between 1:1 and 2:1, but 2:1 is really
ideal and a slightly greater ratio wouldn't hurt.  (A 2:1 ratio
indicates twice as much calcium as phosphorus, while a 1:1 ratio
indicates the same amount of calcium as phosphorus.  When we speak of
this ratio, the calcium content is always written first, followed by
the phosphorus content.)  This ratio is very important for bone growth
and maintenance, as well as for muscle contraction and many other
important bodily functions.  Metabolic bone disease, (see Metabolic
Bone Disease section) as well as many other health problems, can be
caused simply by ignoring this ratio for a short length of time.  In
addition, it should be noted that hypocalcemia (calcium deficiency) is
much more common than hypercalcemia (excess calcium) in iguanas.  This
generally means that iguana owners tend to upset the Ca:P ratio by
depriving their lizards calcium, not phosphorus.  If you take a look
at Table 2: Calcium to Phosphorus Ratios, you will see why.  Only
about one third of the foods listed contain as much calcium as
phosphorus.  When choosing foods for your iguana, try to stick to
those foods that have at least a 1:1 ratio.

The items in Table 2 are listed by their ratios, in descending order.
The information in this table has merely been excerpted from Table 1:
Nutritional Content of Many Fruits and Vegetables, but it has been
included so that you can find the better calcium sources faster.  The
foods which contain Ca:P ratios of less than 1:1 are included because
you will probably find yourself using low calcium fruits or vegetables
from time to time, and I wanted to give you an idea of just how
calcium deficient many of these foods are.  By knowing how calcium
deficient a particular food item is, you can choose additional foods
with high calcium content to try to keep the ratio in the proper
range.  The portion sizes are not included in this table.  Table 1 is
a more complete table of food values, and you may refer to it for
portion sizes.  With the portion sizes in mind, you can actually
calculate exactly how much calcium and phosphorus you are serving your
iguana at each meal.  Most iguana owners do not wish to do this chore,
understandably!  In fact, it is not usually necessary.  What you must
bear in mind, however, is the RATIO of the calcium and phosphorus
contents.  One cup of pineapple pieces, for example, contains 11 mg of
calcium and 11 mg of phosphorus.  That is an 11:11, or 1:1, ratio.
This means that any serving of pineapple, whether it be one cup or one
whole pineapple, will contain this ratio of calcium to phosphorus.
This allows you to at least approximate what Ca:P ratio is present in
the foods your iguana is eating.  For example, if one day you feed
your iguana a diet consisting of pear, green beans, mustard greens,
endive and ***ly pear, you will notice in the table that they all
have Ca:P ratios between 1.06:1 and 2.32:1.  Therefore, your iguana's
diet will contain a Ca:P ratio somewhere between those two, which is
satisfactory.  (But remember, 2:1 is ideal!)  If you stick to the
first 66 fruits and vegetables listed in the table, which are the ones
with ratios of 1:1 or higher, you will have less chance of running
into problems stemming from hypocalcemia.  Do not stick to the very
highest end of the table only, however, as a diet containing too much
calcium can cause hardening of the soft tissues due to calcium
deposits.  This problem can be just as serious as calcium deficiency.

I would also like to point out the importance of another nutrient,
Vitamin D3, at this time.  Vitamin D3 plays a crucial role in calcium
absorption: your iguana will not be able to use the calcium it ingests
if Vitamin D3 is not also present.  Vitamin D3 can be obtained through
exposure to natural sunlight (see Ultraviolet Light section,) and it
is also found in the food your iguana eats.  

If you are serious about maintaining your iguana's health, please do
not stop at the end of this nutrition section; rather, continue on
through the general care section so you can learn about the importance
of things such as ultraviolet light and temperature.  This may all
sound complicated at first, but with the help of the text and tables
in this booklet, iguana ownership can remain a rewarding endeavor.

Oxalic Acid

It is known among nutritionists that oxalic acid, a chemical found in
plants of the genus Oxalis, binds with calcium to form calcium
oxalate, an insoluble salt.  This seemingly obscure fact is a much
overlooked, but very important, point to address when tackling iguana
nutrition.  What that scientific jibberish means is that when you or
your iguanas eat food high in oxalic acid such as spinach, rhubarb,
beets, beet greens, celery stalk or swiss chard, the oxalic acid binds
with the calcium in these vegetables, rendering it unusable.  In even
simpler terms, eating any of those four vegetables in excess can cause
calcium deficiencies.  In humans, this may not be as important because
most of us eat varied diets, not usually restricted to vegetables such
as these.  But because we humans are in charge of our pet iguanas'
diets, and because they are strict vegetarians, it is not difficult to
see how some iguanas might end up being fed a diet consisting largely
of, for example, spinach, which actually has a high calcium to
phosphorus ratio but still contains this nutrient antagonist, oxalic
acid.  Most people are unaware that this seemingly nutritious
vegetable also contains this chemical which binds up that calcium and
deems it unavailable.  The lesson?  Do not include spinach, rhubarb
(which is actually considered to be toxic to iguanas; see Toxic Plants
table,) beets, beet greens, celery stalk, or swiss chard as staple
items in your iguana's diet.  Iguanas have limited space in their
stomachs, so you may not want to waste it with unnecessary foods.  My
piece of advice is to offer these four foods in only very small
quantities, if at all.  Certainly, if the grocery store is out of your
favored greens, one bag of spinach will not harm your iguana.  But you
must understand that you must not offer any of these foods on a daily
basis, or even half of the time.  Iguanas in captivity are notorious
for developing metabolic bone disease, and it is speculated that the
excessive feeding of these foods is one of the reasons for that.  

The Cabbage Family

Like oxalic acid-rich vegetables, many vegetables in the family
brassica  (the "cabbage-like" vegetables) should not be fed in excess.
Cabbage, kale, bok-choi (Chinese cabbage,) broccoli, turnips,
rutabaga, cauliflower, and brussels sprouts can all cause thyroid
problems in iguanas (as well as humans) if too much is consumed.  In
short, do not use any of the eight aforementioned vegetables as staple
items in your iguana's diet.  They will cause metabolic problems
eventually if fed in excess.

Tannins

One last group of foods that is generally recognized by those of us
who are concerned with iguana nutrition are foods that contain large
amounts of tannin.  Tannin binds protein, fights digestion by
inhibiting key enzymes involved, and can also render iron and vitamin
B12 unavailable.  If served in excess, foods high in tannin can damage
the liver.  Foods that contain relatively large amount of tannin are
spinach, carrots, bananas, grapes, lettuce, rhubarb (which is, once
again, considered to be toxic to iguanas and should not be offered
anyway,) and onions.  Offering foods containing high amounts of tannin
is generally not recognized as being as dangerous as, for example,
offering foods containing high amounts of oxalic acid; this
information is simply included to deter you from feeding your iguana a
diet consisting of only the food items listed above.  In addition, I
wanted to reiterate the importance of offering your iguana a very
varied diet, which can help reduce the possibility of your iguana
running into health problems.

Cat and Dog Foods

As was mentioned earlier, many herpetologists now believe that captive
iguanas of all ages should be offered the same type of diet.  It was
once widely believed that juvenile iguanas needed more protein in
their diets than ***s.  Thus, juvenile iguanas were offered foods
such as commercial cat and dog food, insects, and cooked meats.
Although we still recommend more vitamin supplementation for juvenile
iguanas than *** iguanas (see Vitamin and Calcium Supplementation
section), we no longer recommend offering such increased protein to
juveniles.  Examination of the stomach contents of wild iguanas
indicates that iguanas of all ages are folivores, and not omnivores as
many used to believe.  Certainly, your iguana may relish the high
protein foods listed above.  You may offer them occasionally, but only
as treats.  Iguanas are neither cats nor dogs, nor are they omnivores.
Under no circumstances should these foods become a large part of your
iguana's diet.  Even most herpetologists who still recommend offering
increased animal protein in juvenile diets agree that protein-rich
foods should only comprise a very small portion of the diet - around
5% total.  If you feed your iguana a balanced vegetable diet complete
with vitamin and calcium supplements, it should live a healthy life
without these extra foods.  Many iguana owners like to give their
lizards low-fat dog food as a treat every couple of weeks, which
should be fine and not interfere with their normal diets.  If you do
this, please use the low-fat variety, and you might even want to avoid
the beef flavors because beef is higher in fat than other meats.  In
addition, it is better to use dog food than cat food because dog food
contains less protein.  

Commercial Iguana Diets

The manufacturers of commercial iguana diets claim that their products
contain all of the nutrients essential to the survival of green
iguanas.  It is recommended by some veterinarians that offering one of
these formulated diets, without too many supplemental vegetables
(which would throw off the nutritional balance present in the formula)
should be fed to any iguana that will eat it.  However, there are
other veterinarians and herpetoculturists who have found that some
iguanas that are given this diet exclusively develop illnesses due to
dietary deficiencies within a year.  In addition, almost all iguana
owners report that their iguanas' stools become much harder when they
are fed the commercial diets, and it is speculated by some that any
poop that is that hard might have the potential to become impacted
within the iguana's digestive system and cause a detrimental blockage.
The conclusion of many veterinarians and herpetoculturists is that
commercial diets are very new and insufficient research and
experimentation has been done with them.  Naturally, no one wants to
subject their own iguanas to lifelong experimentation with a food
product that has endured such slanderous remarks since its release, so
it may be quite a while before any satisfactory conclusions are drawn.
My conclusion is that  if you have some sitting around, feel free to
use commercial iguana food products on those infrequent days when you
realize that you are all out of greens and really don't have time for
a trip to the grocery store.  But on a daily basis, offer your iguana
what it instinctively eats in the wild: leafy green vegetables.  And
if you ever do offer your iguana the dry commercial food, do make sure
that there is plenty of fresh water available because iguanas obtain
most of the water they need from the vegetables they eat.  Most
commercial diets contain virtually no water at all.  (As a side
remark: I offered my iguanas a dry commercial diet for several months
at one point, and all iguanas remained healthy.  It is impossible for
me to predict whether their health would have suffered had I continued
with the diet.  However, I still prefer offering leafy greens and
other vegetables, as it seems more natural, and it seems to be what
they prefer.)

What About Pizza or Leftover Chinese Food?

Many iguanas relish non-vegetarian items.  Do not panic if you return
to your living room one evening to find that your iguana found its way
into the pizza box that you left on the table earlier.  Just as we eat
chocolate bars, items which contribute nothing beneficial whatsoever
to our bodies, iguanas can have an occasional bite of pizza, cashew
chicken, or even ice cream.  (I might add that chocolate is known to
be toxic to birds and dogs, and I do not know whether any research has
been done with chocolate and iguanas.  Please do not attempt such
research at home.)  Just make sure that nutritious vegetables make up
the bulk of your iguana's diet.  You would not feel very well if half
of the food you ate were candy, but an occasional snack won't hurt.  

The Good Stuff

The good news is that, believe it or not, there are still some
vegetables left that won't harm your iguana.  Collard greens, parsley,
dandelion greens and green beans are some of the favored foods for
iguanas among herpetoculturists.  If you refer to Table 2,  you will
see that they all have calcium to phosphorus ratios over 1:1, and if
you read the last few pages you know that none contain much oxalic
acid or belong to the brassica family that tends to cause thyroid
problems.  In addition, they are all relatively high in many essential
nutrients.

Some foods that are currently recognized as being good choices for an
iguana diet are listed below.  Remember to avoid foods high in oxalic
acid, such as spinach, rhubarb, beets, beet greens, celery stalk and
swiss chard, to avoid cabbage-like foods which can lead to thyroid
problems, such as cabbage, bok-choi, kale, rutabaga, turnips,
cauliflower, brussels sprouts, and broccoli, and to try to stick with
foods that have a calcium to phosphorus ratio of at least 1:1,
preferably around 2:1.  You can certainly offer the undesirable foods
in small amounts, intermittenly.  But considering the wide variety of
other vegetables available to us, it is best if you stay away from
such problematic foods.  

Some good foods for iguanas:  collard greens, turnip greens, parsley,
dandelion greens, figs (raw or dried), ***lypear, endive,
raspberries, leeks, blackberries, grapes, green beans, radish, okra,
pears....
Remember, just because a food item is on the above list does not mean
that you can choose it plus just one or two other items and serve them
only.  The list is only of any use if you try to use many, all, or
more of the items on it.  In addition, you should refer to Table 1 and
Table 2 to try to find other foods to offer your iguana.  All of the
food items on the above list have Ca:P ratios above 1:1, but you can
offer foods with lower ratios if you use calcium supplementstion (see
Vitamin and Calcium Supplementation section) and offer a larger amount
of foods with high ratios.  You must still pick and choose which
combinations are the best, depending on what is available in your
area, what your iguana likes and dislikes, and even price.  It would
be wonderful if I could offer you a sample diet that can be used
exclusively, on a daily basis, but that poses three problems:  1) we
do not know exactly what constitutes a nutritionally balanced iguana
diet; 2) you might not have access to the same fruits and vegetables
that I do on a year-round basis, and 3) your iguana needs variety in
its diet.  Like humans, it will tire of the same old foods and want
something new.  So take a look at the above list, and take a look at
Table 1 and Table 2.  Use the knowledge you have just obtained about
anti-nutrients and formulate your own iguana diets daily.  Feel free
to add nutritious items to the above list if they have been
overlooked.  One of my goals in writing this booklet is not only to
force its readers to memorize by rote which foods contain what and
which don't contain what, but to teach people how to formulate their
own diets for their iguanas, based on the information I have given.  I
cannot simply prescribe a diet; rather, I want to help you formulate
your own.

Vitamin and Calcium Supplementation

Despite our efforts to offer varied, nutritionally complete diets to
our iguanas, iguanas still sometimes wind up with nutritional
deficiencies.  This is probably due to the fact that the foods that
iguanas eat in the wild are simply not available to us.  Their natural
foods probably contain exactly what iguanas need to survive, while the
foods available to us in the grocery store simply do not.  Therefore,
vitamin and mineral supplements have been created for reptiles.
Because juveniles are such rapidly growing animals, it is generally
recommended that they be given more supplement than their ***
counterparts.  As a general rule, mix a small pinch of supplement in
with the food at every other feeding.  For ***s, a larger pinch a
couple times a week should suffice.  Do not go overboard with
supplementation.  Do not feel the need to coat each piece of food with
vitamin or calcium powder!  Just a very light sprinkle over the top of
the food is fine.  If you have multiple iguanas, you may wish to mix
the supplement in with the food so that the first iguana to attack the
food bowl doesn't end up eating all of the supplement powder.  

There are several supplement choices on the market, so you may not
know which one(s) to choose at first.  I recommend you choose both a
multivitamin/mineral supplement made for reptiles which contains a
wide variety of vitamins and minerals, and a second supplement that
contains exclusively calcium, or calcium with vitamin D3.  (NOT a
supplement containing both calcium and phosphorus.)  Most
multivitamin/mineral supplements contain good levels of vitamins and
minerals, plus they contain the proper calcium to phosphorus ratio.
(2:1.)  This is good for giving an overall boost to the nutritional
content of your iguana's diet.  The second calcium supplement,
however, should be used because most iguana owners tend to offer their
iguanas calcium-poor diets.  By offering a straight calcium
supplement, the Ca:P ratio can be raised.  If a calcium supplement is
given that contains a 2:1 Ca:P ratio, the Ca:P ratio will not be
corrected.  (Unless you use a LOT of supplement, which is very
dangerous!)  

You should learn to estimate the calcium and phosphorus levels in your
iguana's diet.  Just look at the foods you have offered, look at Table
2, and decide if the diet is calcium rich or calcium poor, relative to
its phosphorus content.  If you are offering a lot of collard greens,
for example, which have an extremely high Ca:P ratio, you may need to
use little or no calcium supplement.  If the diet seems to be in
between 1:1 and 2:1, you may need to use supplementation only once in
a while.  If for some reason you are unable to purchase foods that
have a Ca:P of 1:1 or greater, you must use supplementation regularly,
and you must also find a source of better food items!

Water

Like most living systems on Earth, iguanas need water in order to
survive.  Iguanas can live for a long time without food, but will
perish quickly if deprived of water.  It is important that you provide
a water bowl in your iguana's enclosure so that it may drink when it
wishes to.  It is also important to keep it clean.  Iguanas often
choose to defacate in their water bowl, and they also bathe in it if
it is big enough.  Considering the high temperatures that must be
maintained in your iguana's habitat,  (see Temperature section) the
water bowl can become a breeding ground for bacteria.  It is a good
idea to change your iguana's water daily, plus whenever you see that
it has been soiled.  

Many people comment that they never see their iguanas drinking from
the water bowl.  This is because most do it very infrequently.
Vegetables are comprised of mostly water - above 90% in many cases.
Thus, your iguana will obtain most of the water that it needs from its
food.  You must still provide a water source, however, as your iguana
will still need more water than its food can provide.  Your iguana
will be especially thirsty on days that it hasn't eaten or on days
that it has eaten dry food, (such as a commercial iguana diet,) so
please do not neglect your iguana's water bowl on these occasions.

When to Feed

As a general rule, iguanas should be fed on a daily basis.  This is
especially true in juvenile specimens.  As your iguana matures, it
will not grow as fast as it did when it was young, so it may not
require as much food intake.  (Relatively speaking, that is.)  These
lizards may be fed every other day if they do not seem to desire food
daily.  However, unlike some other species of lizards, iguanas do not
seem to have a tendency toward obesity and can be fed essentially as
much as they will eat.  

In addition, iguanas should be fed at what we consider to be
lunchtime.  After your iguana's light and heat sources are turned on
in the morning, (see Heating and Lighting section) it will need a
couple of hours to "warm up" before it is interested in food.  11AM
would be a good time to feed your iguana.  If you work or go to school
during the day, you generally have two choices: feeding your iguana in
the morning or in the evening.  Although neither is a particularly
great time, please choose the morning over the evening.  In the wild,
iguanas would be done with their daily routine by late afternoon.  At
least if you offer the food in the morning your iguana can choose to
eat it later.  If there is no food all day, your iguana may become
stressed.

Do monitor your iguana's physical appearance on a daily basis and note
the appearance of its sides.  There should not be pronounced flaps of
skin running down the sides of your iguana.  If there are, your iguana
might not be getting enough food.  Try offering it more at lunchtime.
In addition, the base of your iguana's tail should always be round and
plump, not emaciated looking.  If a larger lunch does not seem to help
your iguana's thin appearance, refer to the section of this booklet
entitled Troubleshooting, which deals with some common problems in
iguanas.  

How to Feed

You should decide how small to chop up your iguana's food based on its
size.  The basic idea is that you want your iguana to have as little
trouble as possible while eating.  This is especially important with
harder or more awkward-shaped vegetables such as broccoli.  You may
notice that although your iguana has lots of nice, sharp teeth, it
does not exactly chew its food.  Most of it is swallowed whole.  Some
people decide to use a food processor to chop up all the food offered
to their iguanas.  When the food is shredded in such a way, there is
little chance that an iguana could ***on its meal.  Use whatever
method is best for you to insure that your iguana will easily be able
to swallow its food.

In addition, you should mix up the food thoroughly.  Iguanas do have
favorite food items, and when it is not mixed well they can easily
pick out the foods they like best and leave the rest.  This can be
dangerous because iguanas need a varied diet in order to obtain all
the nutrients they need for survival.  If your iguana picks out one or
two food items only, it is not getting a varied enough diet.  This is
probably the best argument for using a food processor, because such a
machine can blend the food together so well that one item becomes
indistinguishable from the rest.  I simply use a knife to chop up food
for my iguanas, but I offer relatively small amounts of each type of
food.  This way, even if the iguana does pick out its favorites first,
it will still be hungry and be forced to clean its plate!

If you have multiple iguanas eating from the same plate, you should
monitor each one's food intake to make sure that they are all getting
a little bit of everything.  Alternately, you could feed them
separately.

Eating and Seasons

You will probably find that your iguana eats more in the summer months
than in the winter.  This is normal behavior.  Even in the tropics
cooler, dryer seasons exist, and at that time iguanas eat less.  Some
dedicated herpetoculturists provide "seasons" for their reptiles by
varying their light cycles and temperatures.  Some reptile owners
actually allow their pets a period of hibernation during the winter
months.  All of this is done to try to replicate the animals' natural
environment, thereby creating a less stressful environment.  In
addition, iguanas begin their mating season in what we would call
autumn, and many animals tend to eat less during their mating
seasoons.  So, if your iguana begins to eat less when autumn arrives,
do not immediately despair.  It is probably just their natural
behavior.

HOUSING CONSIDERATIONS

The "Roam Free" Option

Many iguana owners like to allow their lizards to roam free throughout
the entire house or apartment, or at least one or two rooms.  These
are viable situations, but many important precautions must first be
taken into consideration.  As I will discuss shortly, iguanas need to
live in very high temperatures if effective digestion is to take
place.  You will need to heat all the areas that the iguana will
occupy.  In addition, it is not always particularly easy to
potty-train iguanas, who generally defacate daily.  Some iguanas will
choose a particular spot (or maybe two or three particular spots) and
use it faithfully.  In that case, you can place a litter box or
newspaper in that spot for easy cleaning.  Other iguanas may use a
certain area sometimes, but frequently stray from it.  Still others
will return to a particular spot thanks only to sheer coincidence.
You must be prepared to deal with these daily clean-ups.  Iguanas'
stools can stain and many iguana owners already know that some of
their lizards' favorite spots to relieve themselves are beds and
stacks of clean clothes.  In addition to the problem of staining,
general hygeine is extremely important.  It is easy to put off
cleaning an iguana mess if it's in the corner of a room, but that
corner will soon become a breeding ground for harmful bacteria.  

Another important consideration is iguana-proofing the rooms.  Iguanas
can be even more curious than cats, but unfortunately, tend to be much
less graceful.  If you have fragile objects on shelves, they are
likely to be knocked over and possibly damaged by your iguana.
Climbing is facilitated by your iguana's use of its claws.  If much of
your furniture is slippery (wood, as opposed to upholstery) your
iguana will likely slip off and possibly injure itself.  Electrical
outlets can also be hazardous.  Iguanas can get caught in between
radiators and walls, get tangled in stereo wires, burn themselves on
lightbulbs, or even decide to hang out underneath heavy furniture for
several days at a time, thus missing meals and probably cooling down.
You must also consider the iguana's general happiness:  iguanas are
arboreal, which means that they are tree-dwelling in the wild.  They
will want to climb the furniture, which may be impossible for them if
their claws don't have anything to grab onto.  Alternately, their
claws might tear holes in your upholstery if too much wanton climbing
takes place.

Despite all of the above warnings, there are indeed many iguanas that
do share their living space with their owners.  A suitable environment
can be created if you carefully consider the above precautions.  You
might even consider adding some large branches to your decor for your
iguanas to climb.  You might also section off one corner of the room
for use as an open cage.  If you heat that area, supply branches and
feed them there, they may spend much of their time in that area, only
leaving for temporary changes of scenery and for exercise.  One option
is to hang a heat lamp from the ceiling, above your iguana's basking
area.  Iguanas like to bask in hot light (like the sun) and generally
prefer to do that over merely sitting in a heated room.  If you do
choose to let your iguana free-roam, please read the rest of this
section so you can learn about their light and temperature
requirements.  

The Cage Option

Generally, owners of juvenile iguanas choose to house their lizards in
aquariums or other types of cages.  Small lizards are likely to get
lost when released into large areas, so an enclosure of some kind is
recommended.  Aquariums tend to be the most popular choice, probably
due to their availability.  Glass surfaces are also easy to clean, and
allow for high visibility.  Some iguana owners opt to build cages for
their lizards.  A common type of custom cage is one with a wooden
frame, with the sides made of cage wire or plexiglass.  Glass can also
be used, as it won't scratch or bend, but it is much heavier when
coupled with the wooden frame and is more fragile during construction
and when moving.  Glass and plexiglass are popular because they tend
to look nicer than cage wire, allow for optimum visibility of the
lizard inside, and they also keep the heat in the cage.  Cage wire,
however, may be favored by the iguana because it will provide a
climbing material, and also because it allows for ventilation.  (It is
also much cheaper.)  It is crucial to keep the cage warm, but it is
also important to allow the animal inside to breathe.  In general,
when constructing your iguana's cage, you must take many factors into
consideration, which are discussed below.  If you find that you cannot
meet the requirements that are given, it would be a good idea to try
to find your iguana a different home.  Many people buy iguanas not
realizing how much time and money they will need to invest in their
new pets, and it is always best to find a better home for the iguana
than put a half-hearted effort into caring for it.

Cage Size

As a general rule, you should offer your iguana the largest enclosure
that you can possibly afford and have room for.  *** iguanas are
arboreal, which means that they spend most of their time in trees in
the wild.  As juveniles, iguanas spend much more time on the ground,
so smaller, shorter cages are acceptable for a while.  But as iguanas
grow, they want to climb.  This means that you must provide an
enclosure that has very much vertical space.  As a matter of fact, if
faced with the choice of one or the other, it would be better for you
to provide a cage that is 7 feet tall than 7 feet wide or long.  You
may find that this sort of cage structure is advantageous to you as
well, as you can then devote less floorspace to your iguana's
enclosure.  If you are not sure if the cage you have in mind is large
enough for an iguana, there are some general guidelines that can be
followed:  the cage should be at least as tall as the iguana is long.
(Including tail.)  Preferably taller.  It should be about 1 1/2 times
the total length of the animal in length, and 2/3 the total length of
the animal in width.  The iguana should have ample room to walk, turn
around, and climb.  These guidelines should be considered minimum
standards.  Your iguana will probably become quite depressed if it has
less room than this in an enclosure that it will be spending much of
its time in.  (As a side note: I house my four iguanas in a cage that
is six feet tall, eight feet long, and three feet wide, and I would
still prefer it be less crowded in there.)

Cage Toys

Your iguana will not be happy if it doesn't have anything to do
besides sitting on the floor of its cage.  You must provide branches
for climbing in the cage.  The branches should be a little larger in
diameter than your iguana at its largest point.  Climbing is a
favorite pasttime of green iguanas, and you must not deny them this
option.  The branches should sit diagonally within the cage.  Many
iguanas like to sit atop high horizontal surfaces such as shelves, so
you may wish to install a shelf near the high end of the branch.  A
regular shelf will be slippery to an iguana, so it should be covered
with carpet or at least have grooves cut into it so the iguana can
grab on and not fall off.  You may wish to make a place like this into
your iguana's "basking spot", which will be discussed next.  In
addition to branches and shelves, some choose to add ropes or rope
ladders.  These are usually used for juvenile iguanas only.  You must
be careful with large iguanas because due to their weight, if they get
tangled in a rope they can actually suffocate.  Make sure all the
items in the cage are safe and secure, to avoid any accidents!

Heating and Lighting

Heating and lighting the iguana's enclosure are two problems that many
people choose to solve at the same time.  Incandescent spotlights,
available from your hardware or lighting store in a wide variety of
wattages, can keep your iguana's cage both warm and bright.  This is
my heating method of choice.  By placing a spot light at one end of
the cage, you can create a nice temperature gradient for your iguana,
which is essential to its well-being.  The area directly under the
light would be the basking spot, where your iguana will go to warm up
early in the day.  The basking spot should be no hotter than 95
degrees Fehrenheit.  You might want to invest in an aquarium
thermometer so that you may test the temperature at all parts of the
cage.  As the iguana gets farther away from the basking spot, the
ambient temperature decreases.  The coolest part of the cage should be
no lower than about 80 degrees.  As a general rule, iguanas need to
maintain an internal temperature of 88 degrees for about 10 hours a
day if effective digestion is to take place.  My favorite way to mount
the spot light is to***it into a shop-light fixture, and set it
right on the screen or wire top of the cage.  Lights should never be
placed inside the cage because iguanas will climb on them and burn
themselves.  If you do not have a screen or wire top to your cage, you
could shine the light through a screen or wire side.  (Some part of
the cage must usually be screen or wire, or else there will not be
enough ventilation!  See Ventilation section.)  If your cage has no
screen or wire sides but still has effective ventilation, it is
possible to shine a spot light through glass.  You must use a
thermometer, however, to make sure the inside of the cage is at the
correct temperature.

There are also under-tank heaters made to be placed under aquariums to
warm the floor, which is suitable for young specimens that spend much
of their time sitting on the floor of their cages.  They are not very
effective at warming up the air temperature inside aquariums so if you
have an iguana that spends its time on branches or rocks that do not
come into contact with the floor of the aquarium, an under-tank heater
will not do you much good.  In addition, I recommend against  using
"hot rocks," as they are notorious for over-heating and burning
reptiles on their ventral sides.  Also, wild iguanas obtain their heat
from the sun above, not rocks below.  Hot rocks are kind of neat ideas
in themselves in that the manufacturers have given you a mini heater
in the shape of a rock, which might seem perfect for a reptile cage.
But remember - the rock is just a heater, and in the author's
experience, an unstable one at that.  All of the author's hot rocks
have "burned out" and are now useless except for decoration - probably
because it is impossible to keep them from getting wet.  The author
knows several other people whose hot rocks have overheated, thus
resulting in burns on their iguanas.  In conclusion, the only suitable
methods the author has found for heating iguana enclosures has been
incandescent spot lights and regular space or room heaters.  If you
use a heater, make sure that the iguana cannot come into contact with
it and knock it over or burn itself.  Iguanas seem to be the happiest
when they have a basking spot, so you may use a space heater to help
heat the iguana's area, but the iguana should really have a basking
spot as well.  

Vegetable matter contains a large amount of cellulose (which is the
main component of plant cell walls) which most animals cannot digest
on their own.  Iguanas have microorganisms living in their hindgut
which break down the cellulose for them.  These microorganisms need
hot temperatures in order to do their work, so if you keep your iguana
too cool, one of the effects will be poor digestion, which will lead
to problems stemming from malnourishment.

Ultraviolet Light

It is absolutely essential that your iguana be provided exposure to
wide ranges of ultraviolet light.  Natural sunlight is best.  Iguanas'
bodies synthesize vitamin D3 with exposure to UV light, and vitamin D3
is essential for calcium absorption.  It is also speculated that there
are many other benefits of UV light.  If you can, you should take your
iguana outside on sunny days, even when it is chilly.  If your iguana
does not usually live outside, you must purchase "full spectrum"
fluorescent bulbs.  There are many different brands on the market, and
your local pet or lighting store can probably order whatever brand you
want.  You need a full spectrum, not broad spectrum, light, and if
possible, you should buy a few bulbs, all different brands.  None of
the bulbs radiate exactly the same wavelengths, and like with diet,
the widest range you can offer is the best thing you can do for your
iguana.

These full spectrum bulbs can be inserted into any fluorescent "tube"
light fixture.  You can leave these bulbs on all day, for the same
amount of time that you offer light.  You must, however, offer UV
light unfiltered through glass or plastic.  If the light fixture you
have has a plastic "shield," it must be removed.  In addition, if your
cage has a glass or plastic top, adjustments must be made so that your
iguana can be exposed to unfiltered UV light.

Photoperiod

The photoperiod is simply the length of time your iguana is exposed to
light each day.  The recommended photoperiod for iguanas is pretty
simple: plug your heating lights and ultraviolet lights into a timer
so that they turn on for about four*** hours each day.  As the
seasons change, I alter my timer so that their lights turn on when the
sun comes up, and turn off four*** hours later.  In addition to
providing your iguana with "its own" lights for four*** hours a day,
it is essential that you do not keep lights near your iguana's
enclosure on all night.  The photoperiod is an important part of your
iguana's life.  It can become stressed if it never has periods of
darkness.  So if you are a nightowl and tend to stay up all night with
lights and televisions on, please place your iguana's cage in a room
that you would not spend time in.  

Substrate

For use as a substrate (ground material) you should choose whichever
one is easiest for you to keep clean.  Many people successfully keep
their reptiles on newspaper or paper bags.  When soiled, the paper can
be pulled right out and replaced.  Another option is astroturf or some
other kind of carpet.  This is a little nicer to look at than paper,
but is slightly more difficult to keep clean than paper.  If you have
multiple pieces of carpet, you can simply replace the soiled carpet
with the clean carpet.  The soiled carpet can then be rinsed and
cleaned with a bleach solution.  (One part bleach to ten parts water
will do.)  You should always rinse items thoroughly that have been
cleaned with bleach or any detergent.  Still other people like the
look of wood chips.  If you choose to use wood chips, DO NOT USE CEDAR
OR PINE because the oils from these woods can be toxic to iguanas and
other reptiles.  If you do decide to use wood chips, you must be
dedicated to removing them as soon as they are soiled so bacteria does
not accumulate.  You must also be sure that your iguana does not
ingest the wood.  If you feed your iguana in its cage, you should use
a bowl rather than a plate, so that food does not spill out and wood
cannot get in.  Another popular substrate is rabbit food.  These
pellets are not harmful to ingest (as long as they are clean!) and
some people find them more aesthetically pleasing than carpet or
paper.  As with wood chips, you must be dedicated to scooping out
soiled rabbit pellets if you choose to use them.

Above all, you must choose a substrate that you are willing and able
to keep clean.  Minor cuts or scrapes can become infected if your
iguana is living in dirty conditions.  Also, the cleaner you keep your
iguana cage, the less chance that mites will decide to move in.  (See
External Parasites section.)  If you find that you cannot keep a more
*** substrate such as wood chips clean, you must change your
substrate to something easier like carpet or paper.

Humidity

Iguanas come from hot, humid areas of Mexico, Central and South
America.  Most places in North America (other than Mexico) are
relatively cool and arid.  We have already discussed the need for
heating your iguana's enclosure; adding humidity can be just as
important.  Iguanas feel right at home when the humidity level reaches
85-95%.  If your iguana has a large enclosure, you can simply purchase
a humidifier to add humidity.  If your iguana lives in a smaller cage,
you can add humidity in a few different ways.  You can either use a
spray bottle to mist the iguana and the cage once or twice a day, or
you can place a large bowl full of water in the cage which will
evaporate and raise the humidity level.  If you choose the water bowl
method, you may wish to place a heat lamp above it to speed up
evaporation, or placing an under-tank heater underneath that area will
create the same effect.  You will know that your iguana is living in
dry conditions when it has difficulty shedding.  To help your iguana
with its shedding, you may also soak it in warmish water.

Ventilation

A factor in iguana cage design that is frequently overlooked is
ventilation.  If your iguana lives in an "open-air" cage that is made
out of wire or screen on the sides, ventilation surely will not be a
problem for you.  Even aquariums with screen lids usually have enough
ventilation.  Do not, however, use an aquarium with a full hood, such
as is used for fish.  These will not permit air flow in and out of the
aquarium.  We have all been in overcrowded subways or buses that were
so stuffy that we thought we might suffocate.  Now imagine the subway
at a temperature of about 90 degrees fahrenheit, probably with food or
feces at your feet.  Your iguana would not like this scenario any more
than you do!  So make sure there is an air source in your iguana's
enclosure.  There are some aquarium-like iguana cages on the market
that are glass on the sides and the top, with vents spaced around the
sides.  These cages seem to be satisfactory ventilation-wise.
However, if you have a glass top on your iguana's cage, ultraviolet
light will be filtered as it passes through the glass.  (See
Ultraviolet Light section.)  You need to have a cage that is
well-ventilated and that is able to pass UV light through its top or
sides.

Plants: Fake vs. Real

The addition of plants to lizard habitats can be quite aesthetically
pleasing.  In addition, one might hypothesize that captive iguanas
would enjoy the presence of plants, as they live among lush vegetation
in their natural environment.  But you must remember that plant leaves
serve as food for wild iguanas, and iguanas will relish plants as food
in captivity as well.  In the wild, the consumption of plant life by
iguanas is not a problem, as there is well enough of it to go around
and one of its purposes is to serve as food for herbivorous animals.
Similarly, when plants are added to a cage or when iguanas are exposed
to plants in the home, chances are that your iguana will decide to
taste-test the local fauna.  If the taste is agreeable, your iguana
may return to it each day for a snack, leaving the fate of the plant
as questionable.  Many times, iguanas will chew on plants enough to
kill them.  They also tend to damage plants when climbing them.  

In addition to the chance that the plant might suffer, your iguana's
health may suffer as well.  The plant leaves might throw off your
iguana's nutritional intake if it eats too much of a plant that
contains, say, too much protein or phosphorus.  (See section on
nutrition.)  There is also the chance that you may unwittingly offer a
plant that is toxic to reptiles.  If you choose to expose your iguana
to a plant, please refer to Table 3: Toxic Plants in the Tables
section of this booklet.  The plants listed are known to be toxic to
reptiles.  Please keep the plants in the table in mind when decorating
your own living space, even if your iguana lives in a cage.  It is
likely that you will let your iguana out of the cage on occasion, and
escape is always a possibility.  Always keep an eye on your iguana if
you let it out of its cage.

In light of the above information, you may wish to consider purchasing
fake plants for iguana cage decoration.  If you let your iguana out of
its cage or if it shares your living space with you, make sure that
any live plants you may have are out of reach, or make sure that your
iguana seems to be uninterested in them.  In many cases, an occasional
bite won't hurt either the plant or animal.  But the long term effects
can be unfavorable.

Multiple Iguanas

The short answer to the question of whether or not you may house
multiple iguanas in the same cage or living space is "no".  The longer
answer is that all iguanas have different personalities and some will
get along well and some will not.  As juveniles, most iguanas tend to
live in harmony amongst one another.  Do keep this in mind when you
are considering adding another iguana to your pet collection.  An
apparent "friendship" between juvenile iguanas may turn sour within
just a few months as they both mature.  Males tend to be the most
aggressive and territorial.  *** males tend to quarrel, and
male/female groups can also get quite rowdy if the male is interested
in mating.  Groups of females tend to get along better than groups
that contain even one male, but females can be territorial as well and
problems might arise.  Sometimes iguanas can hurt each other quite
badly, so if you are thinking of purchasing more than one iguana you
must be prepared to separate them if their situation calls for it.
This means being prepared to have two separate cages for them, two
separate heating and lighting systems, and two food bowls.  If your
time, space, or resources will not allow this, I suggest keeping only
one iguana until your situation changes.  You never know, without
experimentation, how your particular iguana will react to another
iguana.  (See From Breeding to Egg Incubation section for additional
information.)

IGUANA BEHAVIOR AND MAINTENANCE

Physical Appearance

First, I think it's a good idea for you to know what all those things
are on your iguana's body and what they are there for.  For example,
your iguana has a nose and a mouth just like humans do, but iguanas
don't use their noses for smelling like humans do.  The nostrils are
used for breathing and for salt excretion.   As I will discuss in the
Sneezing section, iguanas sneeze out salt through their nostrils.  The
mouth is used for obvious things like eating and biting, but the
tongue is essentially used for smelling.  You should notice your
iguana stick its tongue out frequently, apparently tasting things as
he walks along (like a healthy iguana should) and this is how the
iguana "smells," mainly for identification purposes.  The ear, or
tympanum, is that clear, roundish object on the sides of your iguana's
head.  Green iguanas can indeed hear, unlike many of their reptilian
relatives, so please take that into consideration when playing loud
music or turning the volume up on the television.  Many iguanas are
not bothered by loud, constant sound such as music, but you must learn
to identify when your iguana is stressed and make the appropriate
changes to calm your pet down.  Generally under the ear is a very
large, round scale called the sybtympanic plate.  This scale does not
have any biological function, but it is considered to be the
distinguishing characteristic of the species Iguana iguana.  If you
ever visit a pet store that has lots of baby green lizards that
resemble iguanas but you're not sure, check for the subtympanic plate.
If the lizard doesn't have one, then it's probably a baby water dragon
or basilisk, lizards that tend to resemble iguanas when young.  Under
the jawbone is a large piece of*** skin called the dewlap.  The
dewlap is extended when the iguana is feeling threatened and wants to
make itself look big and scary.  If your iguana extends its dewlap
when you or another iguana go near it, it may be interpreted as a sign
of stress, or at least discomfort.  If you walk closer and then gently
stroke your iguana on its sides or head and the dewlap relaxes, then
your iguana has probably recognized you and is once again at ease.
The eyes, as you may guess, are used for sight.  You may notice that
your iguana will sometimes close its eyes if pet on the head or neck.
It is not fully understood why this is done, but it is generally
recognized that iguanas who do this are not in pain or discomfort.  In
addition to the dewlap, iguanas also have tuberculate scales, which
are the small bumps on its neck behind the ears, and the spines that
make up its dorsal crest, to help it look big and scary to potential
predators or unwanted mates.  The entire back of the iguana (the "top
view") is referred to as the dorsal region, and the belly (the "bottom
view") is referred to as the ventral region.  The cloacal vent is the
slit right behind the rear legs on the underside of your iguana.
Iguanas use this opening in the skin for discharge of excrement and
for access to the mating organs.  The small bumps that line the
underside of your iguana's rear thighs are called fem***pores.
Especially as your iguana grows, you will notice that there is a hard,
waxy substance excreted through the pores.  It is speculated that
males use this secretion to mark territory.  The fem***pores are
important to you because their appearance can help distinguish between
male and female specimens, as discussed in the Sexing section.

Nail T***

You may have noticed by now that your iguana comes equipped with
twenty sharp claws.  It is a good idea to keep them trimmed.  When
your iguana's nails are too long, they can injure themselves, their
cagemates, and especially their owners!  Long nails can be trimmed in
a number of ways.  Some like to use regular human nail clippers, but
it has been argued that, by their flat nature, they compress the nail
as they clip it, causing unnecessary pain to the iguana.  Also
available are small bird, dog or cat nail clippers, which look rather
like a pair of scissors but with a round area cut out of the blades.
These work just like human nail clippers, except they are geared for
round nails rather than flat nails.  It is believed that these will
not compress the nail as much, thereby causing less discomfort.  

You should also have styptic powder available when t*** your
iguana's nails.  It is available at many pet stores.  In the case that
you cut too far and the nail starts to bleed, the styptic powder
should be packed onto the nail.  It will stop the bleeding.  The only
part of the nail that you should clip off, however, is the pointed
tip.  If you look at your iguana's nails, you will see that there is a
quite defined pointed tip, which is attached to the larger part of the
nail, which is attached to the toe itself.  (It is easier to see in
older iguanas.)  You do not want to cut the larger part of the nail,
for it contains *** vessels.  It would be painful for your iguana,
and sometimes it is difficult to stop the bleeding.  Just clip off the
pointed tip, as that is the only part that does damage anyway.  If you
use a nail file, you can round down the rough edges afterward.

Bathing

Iguanas are, as a general rule, very clean reptiles.  Compared to many
other lizards, iguanas will stay away from their feces and will remain
neutral-smelling.  But an occasional stumble will send them into a
dirtier state and so bathing becomes an essential part of your
iguana's life.  In addition to bathing for hygenic reasons, an
occasional soak in a tub is excellent for your iguana's skin and
facilitates shedding.  
One thing you must remember when assessing your iguana's state of
cleanliness is that it is confined to a relatively small area.
Chances are that it is impossible for it to avoid stepping in feces or
food as it wanders around the bottom of its cage.  Fecal matter and
food become impacted in and around its nails, which can result in a
*** infection if your iguana were to accidentally scratch you or
another iguana.  So you might want to create a regular bathing
schedule for your iguana.  Some recommend a bath once every two weeks
or so.  Some iguanas enjoy bathing, and others do not.  If you put
your bath-fearing iguana on a regular bathing schedule, it will
probably get used to the idea over time.

Bath water should be neither warm nor hot, but lukewarm.  You do not
want to drastically change the internal temperature of your iguana by
simply placing it in the tub.  The water temperature should feel
slightly warm to the touch.  Soaking for 15-30 minutes is recommended,
but with prolonged soaking there is a definite possibility that your
iguana will defacate in the water.  As a matter of fact, soaking in
lukewarm water is one of the procedures used to cure constipated
iguanas.  If your iguana does defacate in the water, you should drain
the tub and start again with fresh water.

In addition, the water should not be too deep.  Your iguana should be
able to stand up and not feel threatened.  Iguanas are excellent
swimmers and can even stay submerged for long periods of time, but at
the same time, they are not aquatic animals and feel more at home in a
tree.  It is also speculated that in the wild, juvenile iguanas learn
to swim by observing *** iguanas.  Juvenile iguanas in captivity are
generally unable to learn in this fasion.  If your iguana thrashes
about wildly in the tub, you may want to try lowering the water level.
Some iguanas will thrash about wildly no matter how much water is in
the tub, so you will just have to get to know how your iguana responds
to bathing.

Excrement and Potty-Training

Most iguanas poop (don't be afraid to say it!) about once a day.  It
is uncommon for them to do so more than once a day, but some iguanas
do skip days.  There should be three parts to your iguana's poop.
There should be a solid bowel movement, not unlike a mammal's.  There
should be a very liquidy part that is pretty gooey, not unlike the
consistency of a beaten egg, which is mostly water.  Finally, there
should be a white section that turns very chalk-like when it dries,
which consists of urates.  Your iguana's excrement should always
contain all three parts.  

Many iguana owners attempt to potty-train their iguanas because it
makes clean-up much easier.  I have never successfully potty-trained
my iguanas for any length of time, but I do know of a few methods that
have worked for others.  One approach is to use the bath tub.  Iguanas
tend to poop when they soak in warm water.  If, on a daily basis, you
let your iguana soak in the warm tub until it defacates, it may get
used to the idea and actually start wandering to the tub on its own to
do its deed.  Usually it is not that simple; some people try generally
decreasing the amount of water in the tub until there is none left,
thereby getting the iguana to poop even when there is no water
present.  If your iguana still does not venture to the tub on its own,
you might want to try putting newspapers in the tub, getting the
iguana used to pooping on the newspapers, and then moving the
newspapers onto the floor next to the tub.  Some iguanas learn to
associate pooping with newspapers, and then search out newspapers to
poop on.

Another method is to simply notice where your iguana usually poops.
If it picks one corner of the room or cage consistently, you might
want to put newspapers or a litter box (filled with something harmless
like shredded newspaper, not kitty litter) in that corner and see if
the iguana still uses that spot.  
Many iguanas, for whatever reason, choose soft places to poop over
hard places.  For example, if given the choice, many will consistently
choose a carpet over a tile floor, or even over newpapers sitting on
the carpet.  You will find this habit especially distressing when your
iguana finally decides that your nice, soft cashmere scarf was the
softest place in the room.  If you are willing to do a lot of laundry,
you might want to use old towels to entice your iguana.  A bundled-up
towel may be just what your iguana wants to use.  It keeps the
furniture and cage clean, but you must also keep the towel clean to
avoid bacterial growth.  Before you throw it in the washing machine,
it's always a good idea to thoroughly rinse the towel first.
Other methods may work better for you.  But you must be willing to
take the time to convince your iguana that there are better places to
poop than its food bowl, your shoes, or its basking shelf, and work
with it on a daily basis.  That is the only way you will be able to
potty-train your iguana.

Growth

Your iguana will grow very rapidly until it is about two or three
years old.  Growth rates in iguanas vary, depending on the individual,
and also on diet.  I currently have three iguanas that are all about
four feet long, and they vary in age from 2.5 - 3.5 years.  The
largest is the 3 year old female, who weighs about 4.5 pounds.  As you
can see, this does not comply with the above statement that males are
generally larger than females.  This illustrates my point that iguana
growth is an individual matter, and that attempting to sex iguanas
based on size is usually inconclusive.  

After your iguana turns three or so, it will continue to grow but at a
much decreased rate.  Iguanas can grow to be six feet long (the tail
is usually about twice to three times the length of the body) and
weigh about 15 pounds.  In captivity, iguanas don't tend to grow as
large as they do in the wild, and most people don't expect their
iguanas to grow any longer than five feet.  

Sexing

Most iguana owners like to know if their iguanas are male or female.
When very young, it is virtually impossible to tell the difference
through physical appearance.  As they get older, however, there are
some visual cues that can help you distinguish between the two sexes.
One of the biggest physical differences between males and females is
the size of their fem***pores, which line the undersides of their
rear thighs.  Males' pores are much larger than females' pores,
especially in older specimens.  It is usually easier to judge the size
of the pores when you have both a male and a female handy, but as you
gain familiarity with the appearance of the pores through observing
your own iguana, observing other iguanas, and looking at pictures in
books, you will be able to tell whether you have a male or a female on
your hands.  
Other differences include body size.  Females tend to be more
heavy-bodied than males, but males generally grow larger, have broader
jowls, and have more developed dorsal crests.  These differences are
much more difficult to see, as iguanas grow at different rates and it
is usually not possible to make any really educated guesses until the
animal is full grown, or at least ***ly mature.  

Finally, males develop a bulge behind their cloacal vent as they
mature.  This bulge is, of course, their hemipenes.  (Male iguanas
actually have two ***es, together called the hemipenes.)  Females do
not have such a bulge in that area.

If your iguana's gender is very important to you, you may wish to
contact a veterinarian who specializes in reptiles and discuss it with
him or her.  Experienced individuals can "probe" an iguana to
determine its sex.  This should only be done by those with lots of
experience, and should only be done if it is very important that the
gender is known.  If performed incorrectly, this procedure can result
in injury.  

From Breeding to Egg Incubation

If you have only one iguana that tends to get aggressive in the fall,
you probably have a male on your hands that is interested in mating.
Some males get especially aggressive at this time and turn on their
owners!  Some iguanas actually attempt to mate with their owners.
Many male iguanas simply act a little territorial during mating
season, and exhibit head bobbing and act a little more defensive than
usual.  Others become *** and the best thing one can do is to stay
away from the *** male iguana during mating season.  This
difficult behavior usually passes after a few weeks, however, and most
iguanas turn back into their old, lovable selves after they're through
thinking about mating.  Lone female iguanas do not tend to change
their behavior during mating season.

If you have multiple iguanas and at least one is male, you might have
some big problems to deal with during mating season.  Your iguanas may
exhibit male-male aggression, and male iguanas can certainly injure
one another.  Your male iguanas will also try to mate with your female
iguanas.  First, the male will bite down on the back of the female's
neck.  Then, once he has her under his control, he will wrap his body
around hers so that their cloacas are next to one another.  He will
then evert his hemipenes (male iguanas have two ***es) and attempt
to force them inside the female and deposit his ***.  Sometimes,
especially if there is a great size difference, the male will not be
at all successful.  As in humans, not all mating attempts result in
fertilization of eggs.  You will know if your female iguana becomes
gravid (pregnant): her abdomen will become large and lumpy, and she
will also go off feed for a few weeks prior to egg-laying.  If your
female iguana does become gravid, you must supply her with a little
extra calcium in her diet, and you must supply her with a place to lay
her eggs.  As I have not had experience with gravid iguanas, the
following information has been supplied by Melissa Kaplan:

        "Females need as much exercise (primarily climbing) as
possible to ensure smooth laying.  One of the most common problems
with females in captivity is egg binding resulting in C-section and
hysterectomy.  Many vets actually recommend spaying females routinely
to prevent the problem.  It is, of course, less costly for you and
less stressful for the ig if she can just get the exercise she needs.
This is probably the best argument for keeping igs free roaming or
housing them in very large (wide AND tall) enclosures with lots of
branches and other climbing apparatus.  
        The iguana does not begin to "show" until the last couple of
weeks of the gestation period.  (Which lasts a total of two months.)
She will be getting fatter with the eggs as she is losing weight, so
she won't look much different, albeit her belly and sides will be more
taut.  You will be able to feel some of the eggs along her sides
before they are developed enough for you to be able to see them.
Generally, a row of two eggs on each side will be felt.

Preparing the Egging Box
        Females dig burrows underground and excavate a small cavern in
which they lay their eggs.  They then back out and back fill the
cavern and burrow.  Interestingly enough, many females reuse the same
cavern year after year, and there are recorded instances of more than
one female using the same cavern, digging separate burrows to get
in....
        You need to recreate the digging area by making an egging box,
a place for her to dig a burrow and lay her eggs in a cavern.
Depending upon the size of the iguana, two huge kitty-litter pans,
placed rim-to-rim and duct taped together, with an access hole cut in
one end of the upper pan, will do the trick for a smaller iguana (say
10-12" snout-to-vent length).  Larger iguanas will require a larger
area... one of those squarish outdoor garbage cans (made of plastic,
with a lid) work well as they can be laid on their side and not roll
around.  Duct tape the lid to the can, and cut an access hole at the
highest point (which will be in the side of the lid).  Essentially,
any large, water- or moisture-proof container which you can keep warm,
provide an access hole for the iguana but keep it closed enough so
that all the excavated dirt doesn't come flying out, and can easily
get into yourself to later remove the eggs, will do.  
        Needless to say, you need to fill the egging box with the
proper digging medium before taping it shut.  What you need to achieve
is soil which you can easily push but which will stay in place when
you take your hand away.  Too hard, and the iguana can't dig; too
loose, and it falls back into the burrow or cavern.  I have found the
following proportions to work quite well:

14 parts sterile potting soil (from peat, available from nurseries)
1 part sterile sand (From nurseries, or playground sand from hardware
stores)
9 cups of warm water

        Mix thoroughly together, and test.  If it falls back, add more
water.  If too damp/gloppy/heavy, add more soil or sand.
        This can be quite heavy when you have almost-filled a garbage
can with this mixture, so be prepared with a dolly or a hand-truck, or
prepare it where you are going to be leaving it.  If the iguana's
enclosure is large enough, then place the egg box in side in a warm
area.  The box needs to be placed in a quiet warm area.  A spare
bedroom or closet works well.  Place a heating pad under the
egg-laying container or direct a basking light on it (making sure not
to melt the plastic!).  (To make as much privacy as possible to reduce
stress, hang a cloth over that part of the enclosure so the iguana
cannot see out.)
        Introduce your iguana to the container.  Hold her up to the
opening, let her sniff/taste and look, and then put her down.  When
she is ready, and if you have prepared the soil/sand mixture properly
and the area is quiet and warm, she will go to work.  (If she is
already going crazy trying to dig through the floor and other
surfaces, she is ready.)
        It can take 10 hours or so to lay all the eggs; number of eggs
varies from 12-40+, with older/bigger ones laying more.  First year
layers can lay 18 or so, so don't be fooled by the size of the iguana.
        Once she lays, she will drag herself out and collapse on her
basking area (or set one up for her nearby, with a bowl of water, and
introduce it to her at the same time as you do the egg box).  Keep an
eye/ear out to see when she is done, then be ready with some comfort
food for her - she is going to look like a skeleton.  I steam brussels
sprouts for a couple of minutes until they are bright green, and slice
them up and put in a shallow jar lid.  I will hand feed her some, then
leave her with the plate.  Feed lots of high calcium foods, and be
generous with the calcium supplements for the next couple of weeks.
By the end of the month after laying, she should begin to look like
her old self.
        If your iguana shows signs of twitching, jerky gait or
difficulty using her back legs at any time during the gestation or
after she has laid, get her to a veterinarian for Calcitonin
injections of Neo-Calglucon supplementation.

Incubating the Eggs
        If your female has mated with a male, then there is a chance
that the eggs are fertile; iguanas can produce eggs without being
around males but, just like chicken eggs, they are not fertile.
        If there is the possibility of fertile eggs, you can begin
putting together an incubator to have it ready before the end of the
gestation period.  

Handling the Eggs
        Our fingers, no matter how recently we washed our hands, are
full of oils and bacteria (beneficial to us, but bacteria just the
same) which can harm the eggs.  Before handling them at any time
during the transfer and incubation process, wear surgical gloves.
        Iguana eggs, like most reptile eggs, are white, ovoid
(elliptical rather than round) and slightly soft or leathery rather
than hard and brittle like a bird egg.  Pick up gently at the ends of
the egg, and avoid squeezing.

Home-Made Incubator
        One method of constructing a home-made incubator is to fill a
plastic lidded container with a mixture of vermiculite (not perlite)
and water, in equal volumes by weight (the vermiculite should be well
saturated but there should be no puddles of water).  Poke holes in the
lid.
        In an aquarium or other water-tight container equipped with an
adjustable lid or cover, fill the bottom with several inches of warm
water.  Using a submersible water heater (as for aquariums), keep the
temperature at 86-87 degrees fahrenheit or whatever temperature is
required to keep the air temperature within the enclosure at 86-87F.
Place two bricks or another container upside down to form a base on
which to rest the vermiculite-filled box.
        The tank and box together form the incubator.  The box will
hold the eggs, the water heat and humidify the environment, and the
lid of the tank can be adjusted to let out excess humidity and to help
regulate the internal temperature.  Make sure your two thermometers
(the one on the heater and the one monitoring air temperature at the
same level as the box) are clearly visible to you.
        Once your iguana has laid her eggs and is resting comfortably,
you can carefully dig up her eggs and place them in small depressions
(made with your thumb or the back of a spoon) in the surface of the
vermiculite.  Keep the eggs oriented in the same direction: the side
of the egg that was facing up when you dug it up should still be
facing up when placed in the vermiculite.  You can gently mark the
tops with a pen.  Any eggs which are clumped together are best left
together.
        After your eggs are in place in the vermiculite, top with a
layer sphagnum moss which has been dampened in warm water (this is
available along with the vermiculite at nurseries and many hardware
and large grocery stores).  Place the lid loosely on the vermiculite
box, and place on the base in the aquarium.  Cover the aquarium
leaving a slight opening to vent out excess humidity.  Open completely
every couple of days for a few minutes.  

Commercial Incubators
        There are several types of incubators made for the bird
industry, both for poultry and pet birds.  The Hova-Bator (R) is one
type.  It is a foam box with ventilation and troughs in the inside
bottom into which water may be poured.  One suggested use for
Hova-bators is to fill several deli cups or margarine containers with
the vermiculite-water mixture, and place several eggs in each one.
The moss-topped containers are then placed on the screen, and the
Hova-Bator cover put into place.  The unit should be plugged and
brought up to temperature several days before the anticipated date of
laying.  

Incubating
        The incubation period is about 90 days.  Check the eggs
regularly (say, every several days).  Generally speaking, eggs which
collapse or turn moldy are not viable.  But surprises can happen.  If
an egg is getting moldy and you want to take a chance on it, separate
it from the other eggs by putting it into its own container; remember
to wear gloves when doing this, and to avoid knocking the moldy egg
against anything as you move it to its new container, and to take off
and throw away the gloves, washing your hands and don fresh gloves if
you are going to be handling any of the other eggs."

So you may want to make a decision once your iguanas become ornery
about whether you should separate them or not.  If you have multiple
males, they can wound each other, sometimes very seriously.  Males can
also seriously wound females during their mating attempts.  You may
also wish to decide whether or not you want your male mating with your
female, because you might not be ready to deal with egg laying and
incubation.  If you ever decide to own multiple iguanas, you must be
prepared to separate them so they don't injure one another.

Handling

Handling iguanas is relatively simple.  You should not just use one
hand and pick it up from above, around its middle.  You should instead
use two hands, each one supporting the underside of the iguana in
different places.  From behind, I place my right hand under the
iguana's chest area, and my left hand around the vent area.  I also
use my left hand/arm to support the tail.  This becomes much more
important in large iguanas.  You basically want to become a big, soft,
warm branch for the iguana to climb on.  It does not want to be held
on to; rather, it wants to hold on to you.

You must be careful with the iguana's claws, however, when you are
trying to pick it up.  If it is holding on to a branch or especially
fabric of some sort, it is probably digging in with its claws.  You
should not simply grab the iguana and pull straight up.  You should
instead use your fingers to gently unhook each claw from the material
it is hooked into.  This way, there is less chance of claws ripping
out, legs becoming injured, or your upholstery tearing.

Head Bobbing

Your iguana may exhibit a head bobbing display.  This generally begins
happening after the iguana is 1 or 1.5 years old.  It can be a
territorial display or it could be a mating ritual.  If there are no
other iguanas around, your iguana may bob its head at you to give you
a signal.  It may want you to leave it alone or to get away.  Iguanas
sometimes bob their heads when they see their reflection in mirrors.
It is generally recommended that you keep your iguana away from
mirrors.  If there are other iguanas around, a head bobbing display
could be territorial, meaning "get off my branch" or "get out of my
way" or "get away from my mate".  If you have a male and a female
iguana, the male might bob its head at the female if it is interested
in mating.  All of these are normal displays and should not be worried
about, unless your iguanas seem to be acting very territorial toward
one another.  If this is the case, they may have to be separated.

Shedding

Your iguana will shed its skin throughout its entire lifetime.
Juvenile iguanas shed their skin quite often because they grow so
quickly.  ***s do it as well.  Unlike snakes and some other lizards,
iguanas do not shed their skin in one large piece.  Rather, it comes
off in many small pieces.  Also, they do not generally shed their skin
within a short time.  Some iguanas seem to shed constantly, starting
with their feet, then their heads, bodies, tail, and then start again
with the feet.  You should not "help" your iguana with its shedding
because you might accidentally pull off some skin that was not yet
ready to shed.  You may want to give your iguana a bath when it is
apparent that it is about to shed, however, as it may ease the process
for your iguana.

Tail Regeneration

Your iguana might at some time in its life lose part of its tail.  In
the wild, this serves as a defense mechanism against predators.  If a
bird or other animal grabs the iguana's tail, the tail can actually
drop off and even wiggle for several seconds to distract the predator
while the iguana gets away.  In captivity, iguanas lose their tails
only by accident.  You should never grab your iguana by the tail
because it will break off.  Tails usually do grow back but they do not
look like the original tail.  In most cases it is a dull brown, has
different-looking scales than the rest of the tail, and it never grows
back quite as long as the original tail.  If your iguana's tail does
break off, you may try to keep the area clean but you should not have
to do anything other than that.  It should grow back on its own.  But
if you suspect that your iguana is having problems following tail
loss, consult a veterinarian.  

Sneezing

Your iguana may sneeze quite often.  In most iguanas this is a normal
behavior.  Iguanas do not sweat as humans do, so they do not excrete
salt through their skin.  Instead, they do it by sneezing.  There is
no need to alter the salt content of your iguana's diet if it seems to
be sneezing a lot or hardly at all.  If you house your iguana in a
glass enclosure, you will find white spots on the glass.  This is
simply what your iguana sneezes out.  It cleans up relatively easily.

However, iguanas can also contract respiratory infections.  This can
happen when your iguana is not breathing clean air, such as air
surrounding a dusty substrate, and when it is kept in cool conditions.
If your iguana breathes loudly, possibly with its mouth open, it might
have a respiratory ailment and you should consult a veterinarian.
Bubbles or liquid outside the nose and mouth can also be indicative of
a respiratory infection.  If you ever suspect your iguana to be ill,
always keep it a little warmer than usual.  (Still provide a
temperature gradient, however.  See Heating and Lighting section.)

TROUBLESHOOTING

Consulting a Veterinarian

Veterinarians tend to be a little-used resource among iguana owners.
There are indeed a growing number of veterinarians who specialize in
reptiles and amphibians, and their help can sometimes be invaluable.
Virtually no illnesses that your iguana may contract are easily cured
without the help of a veterinarian.  There are medicines and
recommended dosages for herps, and veterinarians can prescribe them
for your iguana.  I highly recommend finding a veterinarian in your
area long before you have a problem with your iguana.  I also
recommend yearly check-ups, because sometimes a veterinarian can spot
a problem that you may miss.  You can also call your veterinarian if
you need advice.  Most will be happy to talk to you on the phone about
your iguana if you have a question.  

In addition, I do not recommend that you visit a veterinarian that
does not specialize in herps.  If you do not know if any of the
veterinarians in your area are knowledgeable about herps, check the
Yellow Pages and make some calls.  Often times the person you talk to
at one veterinarian's office can refer you to another veterinarian.  

Quarantine

It is very important to quarantine new iguanas.  If you purchase a new
iguana, it is possible that it harbors either internal or external
parasites, or even a virus of some kind.  It is a good idea to keep
new iguanas, and all new reptiles, in their own, separate cages until
it can be reasonably determined that they are healthy.  They should be
inspected daily for external parasites, and even if none are observed
for a couple of weeks, it is always possible that eggs are present
somewhere and that they may yet hatch.  If no external parasites are
observed for about four weeks, it is pretty safe to say that the
lizard is mite-free.  You should also take your new iguana in for an
appointment at the vet, because veterinarians are very experienced in
spotting problems with iguanas and he or she might notice a problem
that you missed.  You should definitely take a fecal sample with you,
so your vet can check for internal parasites.  If any exist, the
iguana should be treated and re-checked before it is introduced to
your other iguana(s).  

In general, you should quarantine any new iguanas that you may
purchase for at least six weeks before introducing them to your
established iguanas.  During this quarantine period, you should check
for both internal and external parasites, and observe the iguana daily
to make sure that he or she is acting normal.  Do not introduce any
new specimens to your established specimens unless you are pretty sure
that the new ones are healthy.

Internal Parasites

Your local reptile veterinarian can diagnose internal parasites with a
fecal sample.  If your iguana is acting peculiar, typically not eating
or acting lazier than normal, it could be due to internal parasites.
They can take control inside your iguana's alimentary c***and steal
away the essential nutrients that your iguana eats.  If your
veterinarian finds parasite eggs in your iguana's feces, he or she can
prescribe medicine that will easily take care of the problem.  If you
have multiple iguanas and only one of them is diagnosed as having
internal parasites, you should keep that one away from the others
until the parasites are eradicated.  Usually, if one iguana is
diagnosed with internal parasites and it has been living in the same
quarters as another iguana, both will be given the medicine.  This is
one good reason for yearly check-ups: sometimes you will not know if
your iguana has contracted an internal parasite, but a quick fecal
analysis will reveal it right away and treatment is rather easy.

External Parasites

You should check your iguana daily for any strange physical
appearance.  One thing you should check for are external parasites.
Iguanas do not have keeled, or "spiky", scales so they do not usually
harbor many external parasites.  (Also called mites.)  But around the
spines and head they sometimes do pop up.  These mites will simply
look like little bugs.  They can be black or red.  They must be
removed as soon as you notice them.  You can remove the ones you see
by squashing them, but that is a very slow process as there may be
hundreds of mites present, all laying hundreds of eggs.  

If you do find mites on your iguana you must buckle down with your
cleaning duties.  Your iguana's enclosure should be thoroughly cleaned
and disinfected.  You may use a bleach solution (one part bleach to
ten parts water) for disinfection, and you must rinse those areas
thoroughly after cleaning.  You must clean all branches, rocks,
substrates, bowls and dishes.  I then recommend first bathing your
iguana to drown as many mites as you can right away.  It will be
impossible to get them all that way, as you cannot submerge your
iguana for any length of time.  But it is a start.  You can then
purchase a Pest Strip from your hardware store, home and garden store,
or variety store.  It will look like a yellow block of plastic.  You
should avoid direct contact with this substance.  You can place it
either inside or outside the iguana's enclosure, but make sure that,
wherever you put it, the iguana cannot come into contact with it.  If
your iguana lives in a small cage, you might want to cut off a small
strip of it and place it in a margarine tub with holes in the top.
You need not leave the strip in or around the cage at all times;
rather, you could use it for a few days, then remove it, and then
repeat the treatment each week for about a month.  There is some
speculation that even if your iguana can not contact the strip, the
fumes it gives off are water soluble and could contaminate your
iguana's water supply.  Change your iguana's water frequently when
using a Pest Strip, use as little of the strip as is necessary, and do
not leave it in the cage at all times.  

Sneezing (reprise)

Your iguana may sneeze quite often.  In most iguanas this is a normal
behavior.  Iguanas do not sweat as humans do, so they do not excrete
salt through their skin.  Instead, they do it by sneezing.  There is
no need to alter the salt content of your iguana's diet if it seems to
be sneezing a lot or hardly at all.  If you house your iguana in a
glass enclosure, you will find white spots on the glass.  This is
simply what your iguana sneezes out.  It cleans up relatively easily.

However, iguanas can also contract respiratory infections.  This can
happen when your iguana is not breathing clean air, such as air
surrounding a dusty substrate, and when it is kept in cool conditions.
If your iguana breathes loudly, possibly with its mouth open, it might
have a respiratory ailment and you should consult a veterinarian.
Bubbles or liquid outside the nose and mouth can also be indicative of
a respiratory infection.  If you ever suspect your iguana to be ill,
always keep it a little warmer than usual.  (Still provide a
temperature gradient, however.  See Heating and Lighting section.)

Burns

Thermal burns are relatively frequent for iguanas in captivity, mainly
due to the use of "hot rocks".  As is discussed in the Heating and
Lighting section, "hot rocks" are no longer considered by most
herpetoculturists to be safe ways of heating your iguana's enclosure.
Iguanas can also burn themselves on lights that are used for heating.
Lights should never be placed inside the cage; rather, they should be
positioned outside the cage so they can shine into the cage.  Most
burns are relatively minor and can be treated with a triple antibiotic
ointment.  If the burn seems to be very bad, you may wish to consult
your veterinarian.  In general, if your iguana is still acting
normally (eating, pooping, etc.) the only thing you should concern
yourself with is applying ointment to the burn.  If you think the burn
might be serious, if your iguana is still acting normally, it will
probably be just fine.  Never hesitate to contact a veterinarian,
however, if you are in doubt.  

Nose Abrasions

Nose wounds are common in many lizards that are housed in cages that
have wire or screen on the sides.  If your iguana is unhappy with its
cage, it may spend much of its time rubbing its nose against the
sides, trying to escape.  Some lizards rub their noses against the
cage so often that their flesh is rubbed away clear to the bone.  If
your iguana is exhibiting this behavior, you might want to consider
making some changes with its cage.  Often times, this behavior is
indicative of a cage that is too small, or one that is not tall enough
and does not have ample climbing space.  You must try to make your
iguana as happy as possible, and if it is cutting its nose on the
sides of its cage, you must make changes.  As with general wounds,
(discussed next) all you can really do to help your iguana's nose to
heal is to keep it clean.  If the abrasion seems to be very bad, you
may wish to consult your veterinarian.

General Wounds and Abscesses

Iguanas sometimes wound themselves with their acrobatic antics.
Iguanas frequently break their toes and pull out claws when they leap
through the air, and those injuries are not considered to be very
serious. ...

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