Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Black Spots on Green Iguana

©1996, 2000 Melissa Kaplan


When you got your baby iguana, it likely was a bright, deep overall green with little turquoise and white highlights. The ground color and markings sported by baby iguanas is lost or altered as they leave hatchlinghood - starting about 9 months of age.

Part of the color change for many of them is the appearance lots of brownish-black and black markings including spots, stripes, and 'veining' or 'grouting' (the black surrounds the green or blue scales like grout around tile, and may be unevenly dispersed so it is rather like the tendrils of varicose veins). As the iguana's body and individual scales get larger, you will be able to more clearly see individual scales, and see that many of them contain several different colors - green, yellow, orange, blue, black, white - like some pointillist painter gone mad on this amazing canvas...

Fungus and some bacterial infections may also start out as black spots. Fungal infections have a furry look (but not feel) to them and generally appear in circular patches, often with two to three small circular patches clustered together. These look very different from the normal or emerging natural black markings. Bacterial infections may be crusty to the touch, may or may not be slightly swollen.

If you aren't sure, and there isn't any other iguana owner in your area who can for sure tell you whether your iguana is maturing or has a fungal infection, then you should see a reptile vet, especially if you've never seen one before (it wouldn't hurt to get a fecal check, etc.). Mild topical fungal infections can be treated by the application of an antifungal ointment or cream such as Lotrimin or Micatin (yeast infection creams for athletes foot and other fungal infections).

It should be noted that untreated or serious topical fungal infections can invade the skin and underlying tissue and infect the blood and so the entire body, and ultimately lead to the iguana's death unless caught in time and treated with systemic antibiotics or antifungals.

Home Testing
You can try a simple home test to determine if the spots are normal, fungal or bacterial. Note that this isn't 100% fool-proof, so if you remain concerned, or the spotting increases, don't play around with your iguana's health - get him to the reptile vet!

  • Get some antifungal cream (like for vaginal yeast infections, or athlete's foot), and put some one some of the spots, repeating a couple of times a day for several days. Do the same on some more spots with an antibiotic ointment. Leave other spots alone.

  • If the treated spots don't clear up at all, it is probably color changes. If the ones treated with the antifungals do, its a fungal infection; if the antibiotic ones do, it's a bacterial infection.

  • You should still see a vet in case the infections have penetrated through the skin into the body, in which case systemic antibiotics or antifungals will be required.

Note: if those little black spots have littler black legs and move around on your iguana's skin and enclosure, then you have reptile mites!

Related Articles:

Black Skin/Blackening Skin Syndrome/Vesicular Dermatitis (Blister Disease)

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