Iguana Care Guide

The green iguana (Iguana iguana) is a tree-climbing herbivore from Central and South America, sold as a small bright-green hatchling, that grows to 3–5 ft (1–1.5 m), with males reaching 6 ft (1.8 m) and 15–20 lb (7–9 kg). It needs a room-sized, heated, UV-lit enclosure and a fresh leafy-green diet for 10 to 15 years or more, and mature males can bite and lash with their tails. VCA calls iguanas suitable only for skilled, knowledgeable reptile keepers, not for children or young teenagers.

Care requirements

Need	What to provide
Enclosure	Floor space plus height to climb and bask. MSD’s arboreal guideline (0.4 m³ per 0.1 m of length) means roughly 6 m³ (210 cu ft) for a 5 ft iguana, so most adults need a custom enclosure or room (VCA; MSD)
Temperature	Basking end 90–100°F (32–38°C), cool end 70–75°F (21–24°C), night no lower than 65–70°F (18–21°C) (VCA)
Humidity	60–85% (MSD)
Lighting	UVB lamp no more than 12 in (30 cm) from the iguana, 10–12 hours a day, nothing between bulb and lizard, replaced about every 6 months (VCA)
Diet	Plants only for adults: 80–90% dark leafy greens, under 20% fruit, under 5% animal protein (VCA)
Lifespan	10–15 years, 25 reported (VCA); FWC gives 19 in captivity (VCA; FWC)
Social needs	Best kept alone. Mature males are territorial (VCA; MSD)
Legal notes	On Florida’s Prohibited list since 2021: no new pets, and existing pets need a permit (FWC)

Juvenile vs adult iguanas

	Juvenile	Adult
Feeding frequency	Daily (VCA)	Daily or every other day; every 2–3 days if overweight (VCA)
Animal protein	Up to 10% of the diet (VCA)	Under 5% (VCA)
Legumes	Cooked lentils or beans allowed, no more than 5% (VCA)	Not listed
Calcium powder	Every other day, about 4–5 times a week (VCA)	Once or twice a week (VCA)
Multivitamin with D3	Twice a week (VCA)	Twice a month (VCA)
Colour and temperament	Bright green, usually manageable (VCA)	Fades to brown, orange or grey-green; males can turn aggressive (VCA)

Housing an adult-size lizard

Plan the enclosure for the adult from the start. An iguana needs horizontal space to walk, eat and defecate, plus a sturdy branch sloping from the floor to the top, placed under the heat and UV lamps so it can climb up to bask (VCA). Glass or acrylic enclosures with good ventilation, or galvanized mesh cages, can work. Keep heating elements and lamps 10–12 in (25–30 cm) above the top of the enclosure, behind a screen, so the iguana can’t reach or be burned by them.

Iguanas exploring glass walls often rub or strike their noses and develop sores. VCA suggests a strip of dark tape around the lower glass at eye level so the iguana can see the barrier. Use paper, recycled paper pellets or reptile carpet as flooring, and keep a spare piece of carpet so you can swap it out at least weekly.

Supervised outdoor time in direct sun is ideal when it is above 80°F (27°C), as long as there is shade to retreat to (VCA). The MSD Veterinary Manual notes that even 1–2 hours a week of unfiltered sunlight has clear benefits for reptiles.

The diet that prevents bone disease

Iguanas are hindgut fermenters: microbes in the gut break down high-fibre plants (VCA). Without enough calcium, vitamin D3 from UVB, or both, they develop metabolic bone disease, which VCA calls common, completely preventable and fatal if untreated. For an adult, VCA recommends:

• 40–50% calcium-rich greens: collard, mustard, turnip and beet greens, dandelion, bok choy, escarole, parsley, romaine, kohlrabi and alfalfa hay
• 30–40% other vegetables: squash, bell pepper, green beans, sweet potato, okra, broccoli, carrots, peas and cactus
• under 20% fruit, as a topping on the greens
• under 5% animal protein, if any

Wash produce well, chop it finely and serve it raw, because cooking destroys nutrients. Some vets allow commercial iguana pellets or canned food to make up 5–10% of the diet. Keep a heavy water bowl the iguana can bathe in, and mist it a few times a week, especially in winter (VCA).

Gotchas

• Buying the hatchling, not the adult. The small green hatchling becomes a 5 ft animal with long claws. Price the adult enclosure before you buy (VCA).
• Tail injuries. Rough handling can break the tail. If half or less is lost it may regrow, but smoother and duller (VCA).
• Breeding-season males. Sexually mature males can become aggressive and territorial and inflict a painful bite (VCA).
• Spinach and chard as staples. They contain calcium but block its absorption. Cabbage, kale and mustard greens contain goitrogens. Feed all of these only in small amounts (VCA).
• Releasing an unwanted iguana. Escaped and released pets are how iguanas became invasive in Florida. Rehome through a rescue or, in Florida, the FWC amnesty program (FWC).

Avoid

• Dog or cat food, which has too much protein, vitamin D, phosphorus and fat (VCA)
• Iceberg lettuce and celery, which are mostly water with few nutrients (VCA)
• Hot rocks, and any heater without a thermostat (VCA)
• Cedar shavings, whose oils are toxic, and sand, gravel, corn cob, walnut shell or cat litter, which can cause blockages (VCA)
• UVB filtered through glass or plastic
• Insects or pinkies as a regular food for adults