I just bought/rescued an iguana today. He is eating regularly, as far as i can tell and is alert. He is just so skinny and you can really tell at the base of his tail and hips. I bought him thinking I could just feed him and he would plump up, but now I'm worried something is really wrong with him. Any help or advice?
Get a fecal exam done make sure he has no parasites. Make sure he gets plenty of fluids you can do this by misting his food. You may also feed him plain cooked pasta, and wheat bread along with his greens and veggies, this should help put on some weight. I have an Iguana who is pushing 4 years old now that was once just as emaciated as yours.