Iguanas are a specific type of herbivore, known as folivores, that primarily eat leaves such as spinach or mustard greens. However, not all types of leafy greens are created equal, as some contain much more nutritional value. Some can even be harmful when fed too frequently.
Iguanas can eat spinach, but they should only do so sparingly. Spinach contains high levels of oxalic acid which can inhibit the absorption of calcium, and can imbalance the 2:1 calcium-to-phosphorus ratio. The imbalance can lead to Metabolic Bone Disease (MBD), and result in permanent bone deformations, brittle bones, and even broken bones.
However, just because spinach contains high oxalate levels doesn’t mean you should never feed it to your scaly pet. I’ll teach you the correct quantity and manner in which to add spinach to your iguana’s diet to both avoid unwanted side effects and obtain its health benefits. Let’s begin.
Can Iguanas Eat Spinach?
Yes, iguanas can eat spinach, but only infrequently. I’ll go over in more detail how often you should feed spinach to your iguana, but for now just make sure to keep that in mind.
Since iguanas mostly consume leafy greens, you’d think spinach would be an ideal staple food, but unfortunately, it is not.
Spinach contains high levels of oxalates and low levels of calcium which can offset the 2:1 calcium-to-phosphorus ration.
Additional leafy greens that can also affect the 2:1 ratio include:
- Bok choy
- Kale
- Swiss chard
- Chinese cabbage
- Beet greens
Spinach Health Benefits
Although spinach contains many downsides if overconsumed, it can nevertheless be a great source of food for your iguana.
Nutrients
Like most leafy greens, spinach contains a wide range of nutrients that can be very beneficial for your iguana’s health.
According to the USDA, spinach contains the following nutrients:
- Fiber
- Calcium
- Iron
- Magnesium
- Potassium
- Sodium
- Vitamin K, C, A, B9
Spinach Side Effects
Although an iguana’s diet consists of primarily green leaves, it’s important to remember that not all green leaves are created equal, and some, such as spinach, can actually be harmful for your iguana.
High Calcium Low Phosphorus
As I previously mentioned, iguanas must at all times contain a 2:1 calcium-to-phosphorus ration in order to maintain healthy bones. I could probably write an entire post on this subject (and most likely will in the future), but for now let’s go over the most important things you need to know.
The following bulleted items can cause an imbalance in the delicate 2:1 ration:
- Low calcium foods
- High phosphorus foods
- Insufficient vitamin D3 (obtained most from the sun)
- Foods with high levels of oxalates or phytates
Additionally, the consequences of a prolonged imbalanced ratio include:
- Metabolic Bone Disease
- Rubber Jaw
- Soft/brittle bones
- Broken bones
As you probably already assumed, spinach is low on calcium. Therefore, don’t make spinach a staple food in your iguana’s diet.
High Oxalate Level
Spinach contains high levels of oxalates, chemical compounds that reduce calcium absorption in reptiles.
As you already know, reducing an iguana’s calcium-to-phosphorus ration can result in adverse medical problems such as MBD.
Goitrogenic Properties
Like oxalates, goitrogens are chemical compounds found in spinach. Unfortunately, consuming too many goitrogens can result in your iguana developing hypothyroidism, a condition where the thyroid becomes enlarged and fails to work property.
How Much Spinach Should Iguanas Eat?
The amount of spinach an iguana can safely consume is going to significantly vary with every lizard, as factors such as size, time of year, personal preference, and age come into play.
However, for simplicity’s sake, I’ll provide a table below regarding iguana expert James Hatfield’s advice on how much to feed your iguana depending on its size. SVL stands for snout-to-vent length.
| SVL In Inches | Quantity Of Food |
| 5 | 2-4 tablespoons |
| 7.5 | 3-6 tablespoons |
| 8 | 5-8 tablespoons |
| 12 | 2-3 cups |
| 13 | 2-3 cups |
How Often Should Iguanas Each Spinach?
Leafy greens are generally considered a staple food in your iguana’s diet, and should be fed daily. However, since it contains low levels of calcium and high levels of oxalates, spinach should be fed sparingly.
Foods with high levels of oxalates or phytates should only be fed once or twice a week.
James Hatfield
In his book, Green Iguana The Ultimate Owner’s Manual, James Hatfield recommends feeding foods with a large concentration of oxalates only once or twice a week. Doing so will protect your iguana from developing the unwanted medical complications we’ve already discussed.
Best Time Of Day To Feed Spinach
Believe it or not, iguanas love routine, and can even become stressed if their routine is changed.
By the way, click the following link to learn how to recognize signs of a stressed iguana.
In the wild, iguanas usually eat in the late morning or early afternoon after their bodies have had the chance to warm up, and as you probably already know, everything you do for your iguana should mimic their life in the wild as closely as possible.
Therefore, try to feed spinach to your iguana in the late morning. I understand this may be an issue, as most people are at work.
I used to ask my siblings to help me feed my iguana in the late mornings when I knew I wasn’t going to be home at that time. Maybe you can rely on someone responsible in your home to do the same.
However, if that’s not possible, don’t sweat it. Leave the spinach in your iguanas cage. They’ll know when they’re ready to eat.
Where To Feed Spinach To Your Iguana
Iguanas not only like to eat at the same time every day, but they also want to know that you’re going to feed them in the same place every day. Hence, you should set up a feeding station in their cage.
Hatfield recommends doing so halfway between the bottom and the top of the cage, as feeding your iguana on the ground can result in a couple of unwanted complications.
Firstly, iguanas poop on the ground, which means they might accidentally eat their own poop if you leave their food on the bottom of the cage.
Secondly, your iguana may unintentionally eat substrate if fed at the bottom of the tank. Small quantities of ingested substrate is not harmful to an iguana, but frequent occurrences can result in a clogged digestive system.
How To Feed Spinach To Iguanas?
Although you can technically feed spinach leaves to iguanas in the same form they were purchased, it’s still a good idea to take a few precautions.
Wash The Spinach
First and foremost, I always washed Joana’s (my iguana) food before feeding it to her.
Unfortunately, most foods today are grown with herbicides and pesticides which can be harmful for your pet.
Therefore, always wash their food with soap and warm water. Soap is not harmful to iguanas, but nevertheless, I’m sure they won’t enjoy the taste if the food is not properly rinsed.
Shred Spinach Into Smaller Pieces
Unlike humans, iguanas do not contain enzymes in their saliva that begin the digestion process. Therefore, cutting spinach into smaller pieces is extremely helpful for the iguana’s stomach.
In his book, Hatfield states that he used to cut food into 1/8 inch pieces for his iguana until it reached the age of two, and 3/16 inch pieces after the age of two.
However, there is no need to be exact. A rough estimate is more than enough.
More Food Options For Iguanas
Now that you know spinach is not a staple food for your iguana, you may be wondering which other leafy greens can be fed daily.
Once again according to James Hatfield, the following veggies and leafy greens are considered staple foods that can be given to your iguana on a daily basis:
- Collard greens
- Mustard greens
- Escarole
- Turnip greens
- Parsley
- Leeks
- Green beans
- Zucchini
- Celery
- Peas
Check out his post I wrote to learn everything you need to know about an iguana’s diet. Plus, I include a supplementary bonus guide to ensure your little green friend is getting all the nutrients it needs.
Below is table depicting the portions of food according to their category. Keep in mind, you don’t have to be exact, but getting as close as possible to the following percentages will highly benefit your iguana’s health in the long run.
| Food Category | Percent |
| Supplemental Protein | 1-3 |
| Grain-Based Foods | 0-4 |
| Fruits | 10-15 |
| Leafy Greens | 30-45 |
| Other Vegetables | 30-4 |
Incase you’re wondering, I wrote a guide on two fruits, bananas and tomatoes. Be sure to check those out before you begin feeding them to your iguana!
In a nutshell, it’s okay to feed spinach to your iguana, but make sure you’re not overdoing it.