Feeding a Green Iguana
There are a large number of foods that can be fed to an iguana. As with people, some foods are really healthy and good to eat as a staple food, some are good in smaller amounts, and others should only be eaten on occasion as a treat.
When formulating a diet for your iguana, compare it to what you know of a healthy diet for people. Marrows, pumpkin and green beans are all very healthy foods and part of a nutritious, balanced diet for anybody.
However, eating only these foods for a along time would not be healthy for a person, and would result in signs of vitamin, mineral or major nutrient deficiencies.
It is exactly the same for your iguana. Providing a wide variety of foods at the appropriate frequencies and in appropriate amounts is one of the best ways to help your iguana grow and develop optimally.
Iguanas are herbivorous, which means their diet consists entirely of plant material – leafy greens, vegetables and fruit. Each of these 3 groups should make up a certain proportion of the diet. Greens are important because they provide fibre, or roughage, which is very important in these lizards. They also contain valuable vitamins and minerals. Greens should make up 40 – 60% of a healthy iguana diet.
Vegetables provide protein and energy. They are more nutrient dense than greens, and are also more filling. Veggies should make up 40 – 60% of the diet.
Fruits are high in some vitamins, but with their very high water content, they are not rich in most of the nutrients your iguana needs. They do, however, help add colour and variety, making food more attractive to your iguana. Fruit should only make up about 5% of their diet.
An iguana in the wild will take in the foods they eat as they are found in the wild. This means that your iguana is adapted to eating all his foods raw and fresh, and so this is the best way to serve them.
Cooking vegetables and greens destroys a lot of the vitamins and drastically changes the nutrient composition of that food. It is fine to microwave the harder veggies like butternut and pumpkin for a brief period to soften them, and some sources say it may improve the digestibility of these harder veggies, but it is not necessary, and some iguanas will reject the cooked veg, even if it is a favourite when raw.
If one is planning on serving ones iguana cooked veggies, it is preferable to ensure that most of the diet is served uncooked.
One of the most important things to consider when putting together a healthy diet for your iguana is the calcium level in the diet. Calcium performs a number of important functions in the body, one of these being the formation of healthy strong bones as the iguana grows, and the maintenance of this stable skeletal structure throughout life.
Calcium does not, however, function alone in the body. It is influenced by a number of other things in the diet, the first of which is phosphorus. While it is also an essential mineral, Phosphorus tends to bind to calcium, and basically make it unavailable for use in the body.
It is therefore important to ensure that the overall diet contains more calcium than phosphorus. The way to think of this is in terms of the calcium to phosphorus ratio (Ca:P). If Ca:P is more than 1:1, there is more calcium in the food relative to phosphorus.
The ideal Ca:P ratio for a diet would be 2:1. This can be achieved by balancing out foods in the diet that have a low Ca:P content, with foods that have a high Ca:P ratio, as well as by the addition of calcium supplements to the diet. By doing the latter, one not only ensures that there is a good Ca:P ratio, but also makes certain that the actual amount of Calcium is sufficient.
Another factor influencing free and therefore useful levels of calcium in the diet is a factor called oxalic acid, or oxalates. This is a compound that is found in varying levels in different fresh foods. It also binds to calcium in the food and makes it unavailable, so even a food with brilliant calcium levels, and an excellent Ca:P ratio, will actually not supply the body with much useful calcium if the oxalate content of the food is very high. It is important to balance the diet in terms of oxalate content in the same way as one would balance Ca:P ratio of an overall diet. It is fine to feed some foods with a higher oxalate level, if one feeds other foods with low oxalates, and ensures there is plenty free calcium available to the iguana.
Another factor that is important for the absorption of calcium once it has been ingested is the presence of adequate levels of active Vitamin D. Vitamin D is found in the food iguanas eat.
The form that is ingested, however, is not in the active form, and cannot help calcium uptake. Ingested Vitamin D can only be activated if the iguana has been exposed to sufficient UVB radiation.
This means that while adding extra vitamin D to the diet may help your iguana, it can only be of benefit if it is activated by sunlight or an effective UVB light.
A high fat intake will also influence calcium metabolism in the body, as it will prevent calcium uptake.
Something that is essential for every iguana is a calcium supplement. These boost the amount of free calcium in the diet, and will help avoid a calcium beficiency if a diet is not very well balanced.
Most calcium supplements contain calcium gluconate, which is used best by the iguana’s body, but you may come across other calcium compounds. When selecting a calcium supplement, bear in mind that a long term insufficiency of calcium in the diet can cause serious health problems, most commonly a syndrome called metabolic bone disease.
It is thus important to make sure you use a good quality calcium supplement. Ensure that the product you select contains little or no phosphorus. Also do not be fooled by labels claiming to be better because they contain Vitamin D.
It is better to have more calcium in the supplement than to have a supplement with less calcium, but that also contains Vitamin D.
Although it is not a harmful substance most of the time, especially since iguana can get too much vitamin D, which will cause signs of toxicity. For this reason, it is unnecessary and potentially dangerous to supplement Vitamin D.
It is recommended that calcium supplement is given to hatchlings at least 3 days a week, though 7 days is better. Frequency can be reduced as the iguana grows older, with adults getting supplement at least once a week.
Powdered supplements are to be mixed into the food to dilute the powder out and ensure your iguana doesn’t avoid his food because it is covered in a thick layer of dry stuff.
Just remember that too much of anything is not a good thing. This applies to calcium supplements as well.
It is possible to over-supplement with calcium. This can cause health problems that are just as serious as those resulting from a calcium deficiency. Sprinkling powder onto your food and mixing it in is the best measure – if, once you have mixed it in, you can still see the powder, you have put in too