Just thought I'd put in my 2 cents worth on this subject. I've been following the whole edema thing for over 20 years and I definitely have my opinions. When I first started reading this post, I sort of felt like I must be in the Twilight Zone because, unless I'm mistaken, I believe many causes of edema have, for the most part, already been determined though a combination of collective "experimentation", controlled studies, and shared similar experiences.
Edema is generally seen as a symptom of organ (kidneys and/or liver) malfunction or permanent organ damage. The organ malfunction/damage can be caused by dehydration, too much D3 or too much preformed vitamin A among other things.
In my experience (mostly with montane species) and the experiences of many others, most instances of edema are due to hypervitaminosis D3 rather than hypervitaminosis A, as was previously thought in the early days of the Chameleon Information Network. However, as the editor of the CiN and author of the articles on hypervitaminosis A, John Annis, in conjunction with a veterinarian (forgot his name) demonstrated through a controlled study, too much preformed vitamin A alone can cause organ malfunction/damage resulting in edema.
At the end of the second article, they concluded that most commercially reared crickets did not contain enough preformed vitamin A to cause edemas. Overdose of other vitamins, D3 especially, became suspect.
Trioceros montium neonates raised by John Annis quickly developed edemas when fed non-supplemented commercially bred crickets, something I experienced with Trioceros johnstoni and T. melleri. I recall Rob Trenor of RK Reptiles experienced the same thing with CH melleri many years ago. These cases are not isolated. Many cricket foods/chows that a lot of cricket suppliers use contain both preformed vitamin A and D3. In the case of the T. montium, even when the crickets were fed a diet free of vitamin fortified foods for a period of two weeks, neonates still developed edemas, suggesting the crickets can store fat soluble vitamins in their tissues for at least 2 weeks.
Today, many commercial gutloads for crickets are available. some contain too much D3 and/or preformed vitamin A for some species. In my opinion, unless you know what gutloads a particular cricket supplier uses, you are taking a risk of over-supplementing, especially with D3 and especially with montane species. Keep in mind that most commercial gutloads are fortified with vitamins. Many if not most of those gutloads have preformed vitamin A and D3 added, which, by the way, may account for those keepers who have had success raising neonates without supplementing with preformed vitamin A, a vitamin generally considered important in increasing egg viability and for producing strong babies.
Since crickets can store fat soluble vitamins, I don't think it's valid to claim that, "because I don't use powdered supplements containing D3, D3 could not have caused an edema in my chameleon." I'd have to ask, "What do you gutload your feeders with (whole foods or vitamin fortified foods containing D3?) and what did the supplier of your feeders use to gutload their insects with before they were shipped to you?" Too much D3 can't be ruled out unless you know the answers to these questions.
Primarily because vets see way more cases of hypovitaminosis A than they do hypervitaminosis A, I believe preformed vitamin A is most often not the cause of most reported edemas.
Perry
Considering most of the people starting out with chameleons only have calcium with D3 and use that multiple times a week for weeks or months on end until we correct them and do not see any evidence of edema I do not think the results will be what you're hoping for. This experiment has pretty much been performed through misinformation many times already. If D3 was the only factor we'd see it much more frequently.
and where im at now in BFN...the rental property doesnt have a good place to put one itd have to go under the kitchen sink which is actually still pretty small are to house one.. im actually looking into a DI canister.. might be able to set it up in the bathroom
