A green iguana can be a fascinating pet, but it is also one of the most demanding reptiles to keep well. These animals grow large, live for well over a decade, and have very specific needs when it comes to space, warmth, light, and food. Many health problems seen in pet iguanas come down to a few basics: an enclosure that is too small, lighting that does not provide enough ultraviolet B, and a diet that is low in calcium or unbalanced in minerals.
This guide walks through the three pillars of green iguana care — habitat, diet, and health — in plain terms. You will find setup recommendations, a food list with what to avoid, warning signs to watch for, and a simple daily routine you can follow.
Green Iguana Basics at a Glance
Before setting up anything, it helps to know what you are committing to.
- Adult size: commonly 4 to 6 feet (1.2 to 1.8 m) including the tail, with males generally larger.
- Lifespan: often 15 to 20 years with good care.
- Diet: primarily herbivorous as adults, eating leaves, greens, and some vegetables.
- Temperament: alert and often defensive. Taming takes patience, and some individuals never become relaxed with handling.
- Activity: arboreal, meaning they prefer to climb and rest on raised branches.
Because of their size, strength, and long lifespan, an iguana is a long-term commitment rather than a starter reptile.
Setting Up the Right Habitat
Habitat is where most iguana care goes wrong. These lizards need height for climbing, a wide temperature range, high humidity, and strong lighting.
Enclosure Size and Type
An adult green iguana needs a very large enclosure. A practical minimum is roughly 6 feet long, 3 feet deep, and 6 feet tall (about 1.8 x 0.9 x 1.8 m). Custom wooden enclosures with glass or mesh front panels are common because standard glass tanks are usually too small and hold heat poorly.
Screen-only cages can work in warm climates but lose heat and humidity quickly. Whatever you choose, the enclosure must be escape-proof, since iguanas are strong and can push open loose lids or doors.
Temperature and Lighting
Iguanas are cold-blooded and must regulate body temperature using their environment. Provide a gradient so the animal can move between warm and cool zones.
- Basking spot: about 95 to 100°F (35 to 38°C).
- Ambient (cool side): about 80 to 85°F (27 to 29°C).
- Nighttime: no lower than about 75°F (24°C).
Use a digital thermometer or two, plus an infrared temperature gun, to check actual surface temperatures. Heat rocks and hot pads are risky because they can cause burns without the animal noticing — overhead heat lamps are safer.
Lighting matters just as much as heat. A tube-style ultraviolet B (UVB) lamp lets the iguana produce vitamin D3, which is needed to absorb calcium. Without adequate UVB, even a good diet may not prevent bone disease. Replace UVB bulbs on the schedule the manufacturer gives, usually every 6 to 12 months, because they lose useful output long before they stop glowing.
Humidity
Target roughly 60 to 80 percent relative humidity. A hygrometer is inexpensive and worth having. Mist the enclosure once or twice daily, use a moisture-holding substrate, and provide a large shallow water bowl for soaking and drinking. Good ventilation prevents the enclosure from becoming damp and stagnant.
Substrate and Decor
Safe options include a soil-free, chemical-free bedding such as coconut fiber or plain paper, depending on how easy you want cleaning to be. Avoid loose sand and small bark chips that can be swallowed.
Add thick, sturdy branches for climbing, a raised basking platform, and a hiding area. Plants should be non-toxic or artificial, since iguanas will sample almost anything green.
Building a Healthy Diet
Adult green iguanas are plant eaters. A proper diet is high in fiber, low in protein and fat, and rich in calcium relative to phosphorus.
Everyday Greens
Dark leafy greens should make up the bulk of most meals:
- Collard greens, mustard greens, and turnip greens
- Dandelion greens and watercress
- Escarole and endive
- Small amounts of bok choy or parsley
Vegetables and Occasional Fruits
Roughly a quarter to a third of the meal can be other vegetables, chopped small:
- Winter squash, zucchini, and green beans
- Bell pepper, parsnip, and snap peas
- Fruit such as papaya, mango, or berries — as a small treat, not a staple
Calcium and Mineral Balance
Calcium is the most important nutrient in iguana feeding. Aim for a calcium-to-phosphorus ratio of around 2 to 1. Lightly dust the salad with a calcium supplement several times a week. If your UVB lighting is strong and correct, a calcium powder without added vitamin D3 is usually the safer default; discuss any adjustments with a reptile veterinarian.
Avoid feeding large amounts of foods that bind calcium, such as spinach, beet greens, and rhubarb. Also skip iceberg lettuce, which has almost no nutritional value.
Foods to Avoid Entirely
- Avocado, chocolate, onions, and garlic — these are toxic to many animals
- Dog food, cat food, and other high-protein animal foods
- Dairy products
- Processed human foods, salty snacks, and sugary items
Feeding Schedule
Feed juveniles once or twice daily. Adults generally do well with one large salad per day. Chop food into bite-sized pieces, remove leftovers within a few hours to prevent spoilage, and always provide clean water.
Health Basics and Warning Signs
Iguanas often hide illness until it is advanced, so regular observation is important.
Signs of a Healthy Iguana
- Bright, clear eyes and smooth skin
- Strong grip and the ability to lift its body off the ground
- Steady appetite and regular droppings
- Alert behavior and basking in normal patterns
Common Problems to Watch For
Metabolic bone disease. Soft or rubbery jaw, bent limbs, tremors, or difficulty walking are classic signs. It usually traces back to poor UVB lighting, low calcium, or both.
Dehydration. Sunken eyes, dry skin that tents when gently pinched, and reduced droppings may indicate the animal is not drinking or the humidity is too low.
Shedding problems. Retained skin, especially on toes and the tail tip, can tighten and cut off circulation. Soaking and gentle humidity increases usually help.
Respiratory infection. Wheezing, bubbling around the nose, or open-mouth breathing can point to infection, often triggered by temperatures that are too low.
Burns and injuries. Heat rocks, hot lamps placed too close, and falls from improper branches are common causes.
Handling and Hygiene
Approach slowly and support the body and legs rather than grabbing the tail. Keep handling sessions short at first and let trust build. Always wash your hands before and after contact, and clean the enclosure regularly, because reptiles can carry bacteria such as Salmonella.
A Simple Daily and Weekly Routine
- Check temperatures and humidity each morning.
- Offer a fresh salad and clean water.
- Mist the enclosure once or twice.
- Remove uneaten food and clean droppings.
- Observe eyes, skin, posture, and appetite.
- Once a week, do a deeper clean of surfaces and water bowls.
- Check UVB and heat bulbs for proper function and age.
When to See a Veterinarian
Contact a veterinarian experienced with reptiles if you notice soft bones, weight loss, persistent diarrhea, breathing difficulty, bleeding, or a sudden refusal to eat for more than a few days. Annual checkups and periodic fecal testing are wise preventive steps.
Conclusion
Green iguana care comes down to three priorities: a large, well-lit enclosure with the right heat and humidity; a plant-based diet with proper calcium balance; and close attention to daily health signs. Get those basics right, and you greatly reduce the risk of the most common problems these animals face.
If you found this helpful, explore more practical guides on reptile setup, feeding schedules, and general pet care to keep building your knowledge.