Hello,
I am cutting and pasting a previous post that I have written. It explains impaction in relation to leopard geckos. Overall however, it explains impaction and how impactions are created. This aspect of my post would cover all species of reptile as impaction is the same in all. It is an obstruction.
I feel that sand is a "safe" substrate for bearded dragons that have reached adulthood. Smaller dragons, as with most if not all reptiles, should be kept off ALL particulate substrates. The smaller the intestinal tract, the more likely the animal will become impacted.
This is my previous post:
There are 2 types of impaction. (Well there is one type of impaction, as the result is always the same. However, there are two "classes" of impaction.)
The first type of impaction is the "Acute" impaction.
An acute impaction is the result of consuming anything that can become logged in the intestinal tract or other vital organs. This can be sand,gravel,rocks,or prey that is too large;among other things. This type of impaction is sudden and the problems that arise will become noticeable far faster than the second class of impaction. In many instances, an observant caretaker will notice behavioral changes with the reptile and after seeking veterinary assistance, will be able to save the reptile.
The second, and far more dangerous type of impaction is the "chronic" impaction.
The term chronic means anything that is persisting for a long period of time or duration. The US National Center for Health Statistics defines it as a condition of 3 months duration or longer.
When the term chronic and impaction are placed together, you now have an impaction that is accumulating over a long duration.
This type of impaction is extremely dangerous because there are very few signs that anything is wrong. In fact, most reptiles that are victims of a chronic impaction will not show many signs of illness until their problems have already surfaced and it is most often too late to do anything about it. (This type of impaction can take years before it shows itself and is noticeable.)
What happens with this type of impaction is that the item in question, most often sand, has individual particles that adhere to the intestinal tract. A majority of the substrate passes, but one or more grains will remain adhered. The intestinal tract now has a tiny speed bump in its lining. In the beginning, this is not much of an issue. Food and other particulates will still pass. However, over time, other grains accumulate and adhere to the initial "speed bump." This in turn,creates a larger "speed bump".
As the "bump" increases in size over time and by accumulation, a dangerous blockage is being created. The opening of the intestinal tract is reduced in circumference dramatically and this makes it more difficult for food and other particulates to pass. The digestive process is slowed down dramatically and the absorption of needed vitamins and nutrients is not being met.
This can cause 2 immediate types of problems. The first is the onset of an acute impaction resulting from the leopard geckos need to add calcium to its diet. Though it is available, the blockage is preventing the necessary amounts to be digested. The primary cause of an acute impaction though is due to a lack of vitamins and nutrients in the diet. The Leo in turn begins eating the substrate directly in an attempt to gain the required nutrients. Now you have an acute impaction that has amassed from a chronic impaction.
What could also happen is toxicity. A leopard gecko that has either an acute impaction or a chronic impaction will defecate less and less. In some instances, defecation ceases all together. This causes a buildup of "toxic" substances in the body. With the severe accumulation of sand in the intestinal tract, stomach, and bowel; the reptile can not pass any of these substances and their blood becomes "poisoned". This can lead to a sudden, "unexplainable" death in the leopard gecko. It can also lead to tremors, convulsions, lack of appetite, lethargy,etc.
Particulate substrates are always going to be a controversial debate.Every reptile that is subjected to particulate substrates is going to be subjected to the chance that their reptile is going to succumb to an impaction.(Every enthusiast agrees that the chance is always there.) The chance of an impaction is more severe in smaller reptiles that have smaller intestinal tracts to begin with.
With leopard geckos, it is highly advised to use alternative substrates. Shale,granite, and other larger "rocky" materials can create a beautiful enclosure without the chance that the substrate will be consumed. Also, fabrics can make wonderful substrates as well.
Here is a picture of one of the enclosures that I have designed for my Leopard Geckos. notice that the substrate appears to be sand. Also note that their are live cacti in the tank.
There are no substrates that are 100% safe. There is always some sort of risk involved. With adult bearded dragons, the risk of an impaction is lower than that of a smaller reptile. This is due to the size of the animal and its internal organs. Larger organs passing sand will have a much easier time than that of a reptile who's organs are significantly smaller. I won't say that sand is 100% safe with adults. As with all particulate substrates, the risk of impaction is very real. Its a judgment call when dealing with particular species.
When asked about sand and leopard geckos, I say no. When asked about sand and adult bearded dragons, I don't object.
