Marcia,
This is a pretty interesting topic. Although I do not keep Leopard Geckos, I do keep Bearded Dragons and have used T-Rex Dragon Dust VGF Veggie Growth Formula. My Bearded Dragons are young adults now well into breeding age, but have not produced at all despite being fed well and maintained properly. I use the Dragon Dust sparingly as a supplement when I do not have a large variety of greens, or I feed it to my crickets and superworms before feeding the crickets to the lizards. I have been wondering why my pair of BDs has not yet produced, now I am wondering if it is in some way due to the Dragon Dust.
I went to the T-Rex site and viewed the information available for both the Dragon Dust and the Leopard Gecko Dust. The ingredients listed were the same for each from what I could see. At first I thought that was a glitch in their site, but I do wonder - maybe they use the same ingredients in each of their so-called Sandfire Super Foods. I checked the ingredients for the Box Turtle dust, and guess what - it too listed the same ingredients from what I could see in a quick glance. Either this stuff all has the same ingredients, or I read it wrong (maybe they mean these are all the various ingredients in their various Sandfire Super Foods, but not each ingredient is in each type of the Super Food), or there is a glitch with the ingredients listed on their site.
There was something else I noted on the site and on the jar of Dragon Dust I have. They claim this to be a "complete food" on the label of the jar, and as "complete and balanced". On the jar they also claim it: "…provides all of the nutritional requirements of growing juvenile dragons as well as breeding females". I note they also sell a product called Dragon Dust VGF Veggie maintenance Formula. This then is apparently not a supplement but part of a balanced regular diet. Now working on the premise that the Gecko formula likewise provides all the required nutritional requirements for a juvenile or breeding gecko I hypothesize that if you now add this to your geckos' diets, and then take away calcium and vitamin powders, they are receiving a balanced diet without any of what we would normally consider to be supplementation. In other words, while they may be receiving a bit more calcium, vitamins or other nutrients that are contained in these T-Rex products, they are receiving them in the form of a 'balanced diet'. They are not receiving EXTRA supplementation of only vitamins, minerals or calcium as would be the case when you use calcium, mineral and vitamin powders. In essence what they seemingly, at least seemingly to me, would be receiving is a bit more of a balanced diet and not a strong boost of calcium, minerals or vitamins. So I think they are getting what you would 'normally' have given them when you feed them crickets, and whatever other foods round out a Leo's diet. If those normally given foods were healthy and balanced I see little difference between giving them a bit more 'normal' food at each feeding and giving them the regular amount of food dusted with T-Rex dust products in place of that bit more of food - except that is for the actual ingredients of each diet (more on the ingredients below).
I do however see a vast difference between giving them calcium and vitamin supplementation as opposed to either feeding them a bit more or adding T-Rex dust. Now you would not be giving them a normally balanced diet, but one that is disproportionately higher than normal in calcium and vitamins. I am guessing that the effect of your changing to the Gecko Dust and stopping the calcium and vitamin supplementation is that you have cut back on their vitamin or calcium intake somewhat. I hope I am explaining this so it comes across making sense.
I do not think this would be enough to cause infertility or bad eggs but might cause a decrease in number of eggs produced or the thickness of shells. So I wondered on as to what might be causing your problem. When thinking about this I kept the T-Rex product in mind because of your claim that it was only after you commenced to use this stuff that the problems arose. My idea is a simple one, and I am not saying it is right, just that it is a hypothesis. There are a number of ingredients in the Gecko Dust that you do not normally feed your geckos (an assumption on my part). My hypothesis is that these ingredients in part or in whole may be causing some type of problem with reproduction or digestion (which could effect reproduction). Here are the ingredients that I could glean from their website (
http://www.t-rexproducts.com/Dynamic/ingredients.asp?item=83252):
Dried Banana Powder
Dried Honey Powder
Hempseed Flour and Meal
Bee Pollen
Fig Powder
Whey Protein Isolate
Brewers Yeast
Wheat Germ
Calcium Carbonate
Spirulina Algae
RoseHips Powder
Kelp Meal
Haemotococcus Algae
Marigold Extract
Rosemary Extract
Yucca Extract
Probiotics: a special blend of bacteria containing live bacteria
Vitamin Premix: Vitamins Of most importance, are Vitamin A, and Vitamin D-3.
Does this sound like a reptile diet to you? To me it sounds like a health guru's diet for humans (except maybe for the Marigold Extract), and the ingredients list as shown on the T-Tex web site repeatedly says the source of some of the ingredients is the "human food ingredients industry". Of course they could be fine for reptiles, yet I wonder. Some of the ingredients I am a bit concerned about are: whey protein isolate, brewer's yeast, and live bacteria. If I understand correctly, whey is a dairy product or dairy byproduct. Could what I imagine to be an unnatural foodstuff for a gecko dairy product be causing a problem? As to brewers yeast, I wonder if the yeast culture is live, and if so can it be properly handled by a lizards digestive process or could it cause problems with absorption of nutrients that are required for successful reproduction. As to the live bacteria, could that also be a problem? Another guess is that other ingredients of this product that are not normally found in a Leos diet might also cause a problem with reproduction.
Then again maybe the change in diet is all that has caused the problem. There also could be another reason for the problem, but I do find it curious that it only commenced after the change in diet.
Please make sure to post if things return to normal when you discontinue the T-Rex product and return to your regular supplementation routine. I would suggest you also try simply stopping the T-Rex formula for some of your geckos without giving extra calcium and vitamin supplementation. If they start producing normal healthy clutches, and if the supplemented animals also produce normal healthy clutches, you could probably be more suspicious that the T-Rex product had something to do with your problem. You could not yet be sure, but you could place a small wager on it if you were a betting person.
All the best,
Glenn B
