This is an important, though often overlooked, part of successful reptile keeping. Iguanas, like all other animals, carry within them a host of organisms, some beneficial, some not. Because some of these organisms, including Salmonella, can be transmitted to humans and other reptiles, it is important that enclosures and their furnishings be cleaned and disinfected properly. The easier it is to clean the enclosures and furnishing, the more likely it will actually be cleaned as needed. This is a good point to keep in mind when designing and furnishing your iguana's enclosure.
When the substrate is soiled by food or feces, it should be removed and cleaned. At the same time, the enclosure itself and any furnishings which have been soiled should be cleaned. The best cleaner is plain old hot soapy water, swabbed on and thoroughly rinsed off. Make sure that any bits of food and feces is thoroughly removed from the enclosure. To make this process easier, a spray bottle of premixed soap-water solution can be kept on hand for quick and easy use.
The difference between cleaning and disinfecting is that cleaning removes debris while disinfecting kills bacterial and other organisms. A "clean" enclosure is not exactly a germ-free one. One common disinfectant is household bleach, mixed at 4 ounces (one-half cup) bleach to a gallon of water. Swabbed on clean and rinsed surfaces, it is left in place for at least ten minutes to achieve disinfection. The problem with bleach is that it is a toxic chemical whose fumes can be just as deadly as ingesting it or otherwise coming into physical contact with it. It must be rinsed off thoroughly and the enclosure allowed to air-dry prior to moving the animal back in.
Another disinfectant is available in feed stores and through many mail order pet suppliers: Nolvasan® (chlorhexidine diacetate). Mixed at the rate of 4 tablespoons per gallon of water, this highly concentrated chemical kills bacteria and viruses, including stubborn Pseudomonas and Aeromonas organisms. As with the bleach solution, swab the Nolvasan on the cleaned surfaces, let sit for at least ten minutes, then rinsed off thoroughly. The negligible fumes are not harmful and after the enclosure is thoroughly towel dried, the animal can be put back into it.
Food and water bowls should be disinfected at least once a week and whenever soiled by feces. The same goes for any decorative rocks or branches. The former can be boiled in water for thirty minutes, while the latter can be baked in a 250F oven for 2-3 hours. If the branch is too big to place in the oven, submerge into a tub of bleach-water or Nolvasan solution, allow to sit for 24 hours, then rinse thoroughly by soaking in water, refreshed every couple of hours, for at least 24 hours, then let sit to sun-dry for 2-3 days. (Note: "wild-caught" wood and rocks should be treated the same way before being placed into an animal's enclosure).
Before placing an animal in a new tank, or one which has been in storage for some time or one obtained from someone else, it is critical that you take proper care in cleaning and disinfecting it before putting your animal and furnishings inside--bacteria can linger for a long time!
It is important to get all new animals to a veterinarian, especially exotics like reptiles and amphibians. Most of the animals sold in the pet trade are wild caught, and even animals sold by breeders and private parties may be suffering from the effects of stress and transport.
The first thing to know is that not every vet is experienced in treating reptiles. Just as you wouldn't consider going to a pediatrician for plastic surgery, so you shouldn't consider going to a general small animal or large animal vet for exotics such as reptiles. Vets who specialize in treating reptiles have sought additional education, subscribe to veterinary journals relating to veterinary treatment of reptiles, and attend conferences and symposia related to the treatment and care of such animals. The very different metabolisms of reptiles, as well as their variances in anatomy and physiology, means that what works for a dog or a llama will may not work for a iguana, and may in fact be deadly. If you don't know of a vet who specializes in reptiles, check with your local herpetological society to get a list of names. There are lists for herp societies and vets for many states, Canada, the UK and elsewhere in the world on my Herp Society page. You may email me at firstname.lastname@example.org for a list of societies and vets in your state if it is not listed in the Herp Society page. Just in case you need it inthe future, also try to get the name of at least one after-hours emergency clinic which is experienced in treating reptiles.
The first thing your vet will do will be to check your iguana out from head to tail-tip. The iguanas nutritional status and hydration will also be checked to see if it is dehydrated or too thin. The inside of the mouth, the eyes, the folds of skin along the neck, each of the limbs and toes and the abdominal cavity...all will be felt carefully to check for lumps, bumps, cuts and breaks. The lumps and bumps found could be related to infected abscesses or calcium deficiencies; be prepared to answer questions about diet and any possible injuries.
While on the subject of questions, be prepared to answer a lot of them. Your vet will want to know where and when you got the iguana, how hold it is purported to be, what you are feeding it (be specific!), how you are housing it, what you are using for heating and lighting, the temperatures and photoperiods. You should also be prepared to describe the iguana's general behavior and any physical problems you have noted: loose or discolored feces (possible protozoan or parasite infection), favoring or dragging a limb (a possible break or joint inflammation), clicking sounds when breathing or excessive saliva (signs of a respiratory infection), or a jerky gait when moving or tremors when at rest (possible calcium or thiamin deficiency). Iguanas should be alert and move with smooth, rapid motions. If your iguana spends most of its time sleeping and is relatively non-responsive, then tell the vet this, too; lethargy is a symptom of several disorders.
The first test you will have done is a fecal flotation. This checks the feces for the presence of worm ova. Worms live out their adult life cycle inside the host animal, releasing their eggs to be deposited wherever the animal defecates. Other animals coming into contact with the feces then ingest the eggs (referred to as oral-fecal transmission), thus giving the ova a nice place to hatch and set up housekeeping. The flotation requires a nice fresh sample of feces--the brown fecal mass, not the clear viscous or white urates. The feces is mixed in a special solution and pushed to the bottom of the testing container. A microscope slide is placed on top to trap any ova which, being lighter than the solution, will float to the top. The vet or veterinary technician will then look at the slide under a microscope to determine if and what kind of ova there are so that the proper medication can be administered.
If your iguana continues to have diarrhea or the feces are very odiforous, your iguana may have a protozoan infection. Fecal exams to detect protozoans require a bit of fresh fecal material to be mixed with a fluid and smeared directly on a microscope slide; this test is called a direct smear. The veterinarian or vet tech will look all through the smear to see if there are any protozoans present; medication will be administered depending upon the type of organism found.
Typically, the medications for these infections are administered orally and your veterinarian can show you how to administer the second dose at home. If your iguana is very new, you might not have a fecal sample to take with you when you go to the vet; take one as soon as you get it. The vet will have already weighed the iguana and so will know how much medication to dispense.
As iguanas have been imported in ever increasing numbers, and have been selling every more cheaply, they are much sicker by the time they reach the pet store. Five years ago, the incidence of mites on an iguana was almost unheard of; now, mite and tick infested iguanas are all too common. Pet store remedies do not work and pesticides must be used with extreme caution.
Another health problem affects both the iguanas and their humans. Several years ago, there were only scattered reports of Salmonella-infected people who picked up the Salmonella organism from their iguana. Again, due to the increasing numbers and correspondingly poor conditions in which these lizards are maintained by the pet trade, Salmonella has risen dramatically. Salmonella is of especial concern to pregnant women, newborn babies, infants and toddlers, the elderly, and anyone with a compromised immune system, cancer, and HIV/AIDS. Strict disinfection must be done,and contact with new animals limited to persons not vulnerable to infection until such time as the new iguana has stabilized and is healthy; unfortunately, a sick iguana may not shed the organisms, so a fecal exam to test for Salmonella may give false negatives.