Complete Guide to Keeping Green Iguanas Successfully
Understanding Your Green Iguana's Background
The green iguana (Iguana iguana) is an impressive and colourful reptile native to the tropical rainforests of South America and the Caribbean. Known affectionately as the 'iggie', these lizards grow rapidly from vibrant emerald hatchlings into large adults measuring 5 to 6 feet. They are sexually dimorphic, with males exhibiting larger size, prominent dorsal spines, and bright orange dewlaps used for communication and territory display. Green iguanas are diurnal and spend much of their time basking and climbing; in the wild, they live high in the forest canopy near rivers, dropping into the water to escape predators.
Setting Up the Right Enclosure
Given their adult size, green iguanas require very large enclosures. A hatchling can start in a 4ft vivarium, but adults need custom-built enclosures of at least 8ft long, 4ft wide, and 6ft tall. Ideally, a whole room or walk-in vivarium provides the best environment. The enclosure must include sturdy branches, platforms at various heights for climbing, and areas where the iguana can bask comfortably at height.
Substrates like reptile carpet, newspaper, or coconut fibre work well and are easy to maintain. Avoid fine particle substrates like sand, which can cause impaction if accidentally ingested.
Temperature and Lighting
Green iguanas are strict basking lizards and require a pronounced thermal gradient:
- Basking spot: 35–40°C
- Cool end: 26–28°C
- Night-time minimum: 22°C
High-output UVB lighting (10.0 or 12%) is non-negotiable. Without adequate UVB, metabolic bone disease (MBD) will develop rapidly and is often fatal. UV lamps should span the length of the enclosure and be replaced every 6–12 months, even if they still appear to be working, as UV output declines before visible light output does.
A 12-hour light/dark cycle mimicking natural conditions is recommended. Use a timer for reliability.
Green iguana diet and nutrition
Green iguanas are strict herbivores. Their diet should consist almost entirely of dark leafy greens, edible flowers, and some fruits. Appropriate foods include:
- Dandelion leaves and flowers
- Mustard greens, collard greens, and turnip greens
- Hibiscus flowers and leaves
- Butternut squash and courgette
- Papaya and mango (in moderation)
Foods to avoid include spinach, brassicas (too high in oxalates and goitrogens), fruit in excess (too much sugar), and any animal protein, which can lead to kidney failure over time.
Dust food with calcium powder without D3 at every feeding and with a vitamin supplement weekly. Always provide fresh water in a shallow, large dish that the iguana can bathe in.
Handling and Temperament
Green iguanas can become tame with patient, consistent handling starting from a young age. Begin with short, calm sessions and build trust gradually. Never grab an iguana from above or restrict its movements forcibly. An upset iguana may whip its tail, bite, or scratch — all of which can cause significant injury to the handler.
Regular handling prevents the iguana from becoming defensive and territorial. Adult males can become aggressive, particularly during breeding season, and may require more cautious interaction.
Health and Veterinary Care
Common health issues in green iguanas include:
- Metabolic bone disease: Caused by UVB deficiency or calcium/phosphorus imbalance
- Dystocia: Egg-binding in females; a potentially fatal condition requiring veterinary intervention
- Respiratory infections: Linked to incorrect temperatures or humidity
- Rostral abrasions: From nose-rubbing against enclosure walls; reduce by adding visual barriers
Annual health checks with a reptile-specialist vet are recommended. Faecal parasite tests should be carried out at least once a year.
Legal Considerations
Green iguanas are freely available in the UK and do not require a licence to keep. However, they must never be released into the wild. Some non-native species of iguana are considered invasive in parts of the world, including the US, where deliberate release is an offence.
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