Personally, I believe if you start to feed a wild creature then you must continue to do so. For example, if you place a bird feeder out at the beginning of winter then you are obligated to do so throughout the winter as the birds have come to expect it. JMHO. <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />

That being said check out this link regarding food for iguanas. Lettuce is not something they should have very often, if ever.

http://www.greenigsociety.org/foodchart.htm