The biggest problem with iguanas is that most people who buy them are buying a cute cheap little green lizard that fits in a 20 gallon long. They have an image in their mind of a mini dinosaur pet and no concept of what it takes to maintain an adult.

They aren't willing to spend the money to provide an appropriately sized cage for an adult iguana. They aren't willing to spend the money to provide the heat and UVB lighting the iguana needs. They aren't willing to buy and prepare the kinds of leafy greens and vegetables that the iguana needs to thrive. They aren't willing to invest the time to work with an adult iguana that is becoming aggressive.

They see a pretty little green guy and figure that he's going to have a cute little disposition when he's an adult. When Iggy starts exhibiting normal adult iguana behaviors he's suddenly not cute, he's being deliberately hateful.

If I had a buck for every iguana that got dumped with MBD or that got dumped because of normal adult behaviors, I wouldn't be going into work again, ever. I almost wish that the things cost $5000 rather than less than $50. But because they're cheap, they're like Niles--magnificent animals that people ditch when they become difficult; they aren't worth the cost of providing for adequately because after all, they're so cheap to replace that it's not worth the price of a vet visit or a decent set up to some.

I've seen a few beginners take excellent care of iggies and Niles but they are in the minority. Most of the time these animals fall victim to the casual herp owner--they guy who wants something exotic and that is about all that he wants. The casual guy isn't overly motivated to provide the very best husbandry for his animal, he wants something cool to show off to his friends. He's not about to spend many times more than he paid for the animal to care for it properly.

My guess is that the green iguana is overall the most neglected and most dumped and passed around reptile there is. That really pisses me off. Like tegus, these animals are intelligent and responsive to owners who really take the time to work with them. Yet so many of them are discarded after they have suffered the consequences of ignorance and indifferent husbandry.