Poisonous Substrate

Question
Have you ever heard that ground English walnut shells are poisonous? I have recently come back from the vet where they told me the reason for my bearded dragon being so sick was because of a toxin in the substrate, Which has cause his liver to start to shut down and issues with his lungs. I was wondering if you know what this toxin is called and if you had ever heard of this before. The brand of the ground english walnut shells was Zilla and this is not an issue with impaction.

Answer
Hello Jordan,

Well, no, the walnut shells are not poisonous, but, they can be the cause of fatal impactions however.  I do not recommend the use of walnut shells for substrate, or calcisand or any calcium based substrates, they are too dangerous.
How does the vet know that his liver has started to shut down, did he do a blood test?  What type of lung issues is he having?
If he did do a blood test, please email me a copy of them to my home email at:  Drache613@cfl.rr.com

Let's go over your tank setup first, to see what else could be going on.  Such as what type & brand of UVB are you using, is it a fluorescent tube bulb or a compact/coil light?  What foods are you feeding your dragon, & where did you get your food from?  
What are the temperatures in the tank, & what type of thermometer are you using to measure the temperatures?

Is he eating anything right now?

Tracie