Introduction
Green iguanas are strict herbivores, requiring a well-planned vegetarian diet to thrive. Unlike omnivorous reptiles, they need a balanced intake of leafy greens, vegetables, and fruits, with precise supplementation of calcium and vitamins. This guide provides a structured feeding approach for green iguanas at different life stages.
Recommended Diet Types
Fresh Greens and Vegetables
Staples include collard greens, mustard greens, dandelion greens, turnip greens, and bok choy. These should make up 70-80% of the diet. Other options: escarole, watercress, and kale (in moderation due to oxalates).
Vegetables
Offer a variety of chopped vegetables like bell peppers, squash, zucchini, carrots, and green beans. These provide vitamins and fiber.
Fruits (in moderation)
Fruits should be only 10-15% of the diet to avoid excessive sugar. Safe choices: strawberries, blueberries, mango, papaya, and melon.
Commercial Pellets
High-fiber, low-protein iguana pellets can be a small part of the diet (up to 10%) but should not replace fresh foods.
Note: Avoid animal protein, dog/cat food, and high-fat seeds or nuts. Iguanas do not digest protein well and it can cause renal failure.
Portions and Daily Caloric Needs
Portion sizes vary by size and age. Use the table below as a guideline.
| Age/Size | Daily Food Amount |
|---|---|
| Hatchling (up to 12 in) | 1/4 cup chopped greens, 1 tbsp vegetables, small pinch of calcium |
| Juvenile (12-24 in) | 1/2 to 1 cup greens, 2 tbsp vegetables, and fruit (optional) |
| Adult (24-36 in) | 2-3 cups greens, 1/2 cup vegetables, and fruit (limited) |
| Large Adult (36+ in) | 3-4 cups greens, 1 cup vegetables, and small fruit portion |
Activity level: More active iguanas may need slightly more food, but generally, serve enough so that they finish within 20 minutes. Adjust if they are losing/gaining weight.
Feeding Frequency and Schedule
- Hatchlings and juveniles (up to 18 months): Feed once daily, preferably in the morning after lights come on. Offer fresh food daily.
- Adults: Feed once daily, every day or every other day depending on appetite. Monitor weight.
- Timing: Provide food in the morning to allow for digestion during the day's heat cycle.
Essential Nutrients
Iguanas require a specific balance of nutrients. Key components include:
- Protein: Lower than other reptiles (5-8% in adults). Overabundance leads to kidney issues.
- Fiber: Essential for digestion - aim for 15-20% fiber content.
- Calcium: Critical for bone health. Ca:P ratio should be 2:1 or higher. Use a calcium supplement with D3.
- Vitamin D3: Needed for calcium absorption, but UVB lighting is also essential.
- Vitamin A: Found in dark leafy greens and orange vegetables; beta-carotene is safe.
Harmful Foods and Ingredients
Avoid these foods:
- Animal protein: Meat, eggs, insects, dog/cat food - cause kidney failure.
- High-oxalate foods: Spinach, beet greens, rhubarb, parsley (in large amounts bind calcium).
- Goitrogenic foods: Cabbage, kale, broccoli, cauliflower, Brussels sprouts (in excess can cause thyroid issues).
- High-fat foods: Seeds, nuts, avocado - cause obesity and liver problems.
- Toxic plants: Tulip bulbs, ivy, unripe fruit, rhubarb leaves, onions, garlic.
- Citrus and high-acid fruits: Oranges, grapefruits, tomatoes (can cause mouth sores).
Water Intake
Provide fresh water daily in a shallow bowl. Mist greens lightly to increase hydration. Some iguanas may not drink from a bowl; offer a daily bath (lukewarm water) to encourage drinking and aid shedding.
Beneficial Supplements
- Calcium supplement with D3: Lightly dust food 2-3 times per week for adults, daily for juveniles.
- Multivitamin: Dust once a week (avoid oversupplementation).
- Probiotics: Can help digestion, especially if on antibiotics or after stress.
Do not use supplements with high phosphorus or vitamin A preformed (beta-carotene is safer).
Feeding Differences by Age
Hatchlings and Juveniles
Higher protein requirement (up to 8-10%) for growth. Offer finely chopped greens and vegetables, with calcium supplement daily. Feed once daily, 7 days a week.
Adults
Lower protein (5-8%), higher fiber. Focus on calcium-rich greens. Calcium supplementation 2-3 times per week. Feed daily or every other day.
Seniors (older than 6-8 years)
Monitor weight and adjust portions. Softer foods may be needed for teeth. Ensure easy access to food and water. Calcium supplement still needed. Annual vet check-ups.
Signs of Healthy vs. Poor Diet
Healthy diet signs:
- Bright eyes, alert, active
- Firm, well-formed stools (brown with white urates)
- Smooth, even shedding
- Good muscle tone, visible pelvic bones not protruding
Poor diet signs:
- Lethargy, weakness
- Soft or runny feces
- Swollen limbs or jaw (metabolic bone disease)
- Weight loss or obesity
- Poor appetite, sunken eyes
- Abnormal sheds
If any warning signs appear, consult a reptile veterinarian promptly.