How do I keep my green iguana healthy?

What should I know about green iguanas at a glance?

A green iguana grows from a small hatchling into a lizard up to 1.8 m long, most of it tail, and can live 10 to 15 years or more. It needs a reptile or exotics vet who knows iguanas, and an adult needs an enclosure the size of a small room.

What health problems do vets see most in green iguanas?

Metabolic bone disease, kidney disease, egg problems in females, burns and injuries are among the most common reasons iguanas see a vet. Almost all of them start with diet, heat, light or water.

• Metabolic bone disease: soft bones from too little calcium, too much phosphorus, too little vitamin D3 or too little UVB. The Merck Veterinary Manual calls it "a disease of mismanagement" and lists poor appetite, lethargy, trouble walking, a swollen jaw or legs, broken bones, twitching and a prolapse from the vent. Fixing the diet and lighting is the main treatment, and the outlook is good, especially while the iguana still eats.
• Kidney disease: common in iguanas and a frequent cause of death in captivity, according to WikiVet. Diets too high in protein, too much vitamin D and long-term dehydration are linked to it. Signs are vague, like eating less, weight loss, weakness or a swollen belly, so it is often found late.
• Gout: urate crystals in the joints and organs. Merck says it is generally caused by too much protein in the diet, or follows dehydration and kidney disease.
• Follicular stasis and egg binding: adult females can form eggs with or without a male. In follicular stasis the egg follicles grow but are never released, and in egg binding the shelled eggs can't be laid. Both make a female stop eating and need a vet, often for surgery.
• Burns: iguanas don't always move away from a heat source that is too hot. Heat rocks and lamps within reach cause deep burns.
• Abscesses and mouth rot: firm swellings full of pus and infections of the mouth, usually needing a vet to clean them out and antibiotics.
• Tail and toe injuries: VCA warns that tails can break off with rough handling, and its page on iguana problems notes that rings of stuck shed can cut off blood to the tail tip and toes.

Do iguanas need vaccines or deworming?

No vaccine exists for iguanas or any other reptile. Instead, a reptile vet checks a fecal sample, at the first visit and at check-ups, and treats worms or protozoa when the test finds them rather than on a schedule, as the Merck Veterinary Manual describes.

• Fecal exams: bring a fresh dropping to every check-up and to the first visit after you bring an iguana home.
• Cryptosporidium: a parasite that causes weight loss and regurgitation in lizards, with no treatment that works reliably, according to Merck. Keep a new reptile apart from others until a vet has checked it.
• Salmonella: iguanas carry it without being sick. The CDC says to wash your hands with soap and running water after touching your iguana, its food or anything in its enclosure, to keep children under 5 from touching reptiles or their habitat, and to keep reptiles and their equipment out of the kitchen. Never clean the enclosure or bowls in the kitchen sink.

Which signs in a green iguana can't wait?

Iguanas hide illness, so by the time one looks sick the problem is often advanced. Call your vet now if you see any of these.

• Twitching, trembling or a swollen jaw or legs: these are signs of soft bones. Check UVB and calcium and call your vet.
• A female straining, restless or digging without laying: "A female straining or restless without laying needs a vet." A female with a swollen belly who stops eating needs a vet too.
• Trouble walking or climbing, or legs that seem weak: often soft bones or kidney disease.
• Breathing with the mouth open, or bubbles or discharge from the nose or mouth: signs of a respiratory infection.
• Something sticking out of the vent: a prolapse, which can come with soft bones or straining.
• A burn, a broken tail or a bleeding wound: remove the heat source and call your vet.
• Not eating with weight loss or lethargy: iguanas don't brumate. One that stops eating in the cold needs more heat, and a vet if it lasts.

Find a vet who sees reptiles before you need one, because many clinics don't.

How do I care for a green iguana day to day?

Food and light come first. A green iguana needs fresh greens every day, a hot basking spot, strong UVB and high humidity, and the setup decides most of its health.

• Food: plants only. VCA notes that most vets recommend feeding iguanas only plant material, and puts 80 to 90% of the diet as dark green leafy vegetables, with fruit under 20%. Calcium-rich greens such as collard and turnip greens, dandelion, bok choy and escarole should be 40 to 50% of an adult's diet.
• Foods to limit: spinach, Swiss chard and beet greens are rich in calcium but block its absorption, so they shouldn't be the main green. Cabbage, kale and mustard greens are fine in small amounts. Skip iceberg lettuce and celery, which have little nutrition.
• Animal protein: none is the safest rule. PetMD says an iguana's gut isn't built to digest it, and the Merck Veterinary Manual links diets high in protein to gout. VCA notes that most vets recommend plants only, though some accept up to 5% of an adult's diet as animal protein. Dog and cat food is never suitable, because it is far too high in protein, vitamin D, phosphorus and fat. Ask your vet before adding anything that isn't a plant.
• How often: young iguanas eat every day. Adults eat every day or every other day, and an overweight adult less often. Wash all vegetables and fruit first.
• Calcium: VCA suggests lightly dusting food with a calcium supplement without phosphorus about 4 to 5 times a week for young iguanas and once or twice a week for adults. Too much vitamin D harms the kidneys, so ask your vet which supplement and how often.
• Water: fresh water every day in a bowl big enough to soak in. Many iguanas drink and poop in water, and a lukewarm soak helps shedding.
• Heat: a temperature gradient with a hot basking spot. VCA gives 32 to 38 °C at the basking end and 21 to 24 °C at the cool end. At night it shouldn't drop below about 22 to 24 °C, according to PetMD. VCA allows it a little lower, 18 to 21 °C, so ask your vet before letting it fall below 22 °C. Measure with digital thermometers at both ends.
• Burns: never use heat rocks, which VCA says can burn a pet. Keep lamps and heaters outside the iguana's reach, behind a guard.
• UVB: a UVB lamp over the basking spot for 10 to 12 hours a day, close enough to work, since glass and plastic block UVB. VCA advises changing the bulb every 6 months, or as its maker says, because UVB fades while the lamp still glows. The Merck Veterinary Manual notes that vitamin D3 in the diet did not prevent bone disease in green iguanas, so UVB is not optional.
• Sun: direct outdoor sun is the best UVB when it is warm enough, with shade to retreat to and you nearby. Sun through a window doesn't count.
• Humidity: iguanas come from humid tropical forests. PetMD suggests 70 to 90%, with a hygrometer to check. Misting every day and a large water bowl help.
• Space: a hatchling can start in a small enclosure, but an adult needs a custom enclosure or a reptile-safe room with branches to climb and a basking shelf high up.
• Handling: support the body and hold near the base of the tail, never by the tail itself, which can break off. An adult can whip its tail, scratch and bite hard, so VCA says iguanas aren't suitable pets for young children.
• Breeding season: mature males often turn aggressive for a few months each year, toward people and other iguanas. In a small study of male green iguanas in Florida, aggression was worst from late November to February, and castration about 6 weeks before the season reduced it. The season follows the local climate, so in Brazil and elsewhere it falls in other months. Note when your male's behavior changes each year and plan from that. Ask your vet whether neutering makes sense, and wear long sleeves while it lasts.
• Eggs: give an adult female a warm nesting box with moist soil deep enough to dig, every year whether or not she has met a male. Without a place to dig, many females hold their eggs.
• Nails: iguana claws grow long and sharp and can catch and tear. Ask your vet to trim them or show you how.

Is it legal to keep a green iguana?

It depends on where you live. The green iguana is on CITES Appendix II, so international trade needs permits, and many countries add their own rules. Check the rules where you live before you get one.

• Brazil: the green iguana is native wildlife, and keeping one without the authorities' permission is a crime under Law 9,605/1998. The Agência Senado explains that it must be bought from a breeder or shop authorized by IBAMA, with an invoice (nota fiscal) that carries the animal's scientific and common names and its individual identification number. Never buy one at a street market or take one from the wild.
• European Union: the green iguana is on Annex B of the EU wildlife trade rules, according to Species+, so bringing one into the EU needs an import permit. Keep the papers that show where your iguana came from.
• United States: green iguanas are invasive in Florida and Puerto Rico, according to the US Fish and Wildlife Service. Florida made the green iguana a Prohibited species in 2021 under rule 68-5.006 of the Florida Administrative Code, so it can no longer be acquired as a new pet there. People who already had one before the listing could apply for a permit to keep it, under rule 68-5.007.
• Everywhere: never release an iguana. If you can't keep it any longer, ask a reptile rescue or your local wildlife agency.

How do I keep my green iguana's health record?

VetVitae, a free pet health record app, keeps your iguana's weight in grams and warns you when it drops 10% below the highest weight of the last 3 months, a warning skipped after a clutch of eggs. It also keeps the enclosure setup with its temperatures, humidity and UVB lamp, sheds and stuck sheds, eggs, and fecal exams and vet visits.

It suggests iguana routines like Fresh greens, Mist the enclosure and Sun time, and reminds you when the UVB lamp change is due. The certificate of origin and microchip go on the profile. See reptile records, weight, routines and exams and tests.

VetVitae is free on iPhone, Android and the web.

This guide is general information, not veterinary advice. Your vet knows your pet.

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